Horticulturae, Volume 10, Issue 6 (June 2024) – 109 articles

Cold stress is an important limiting factor affecting spring tea quality. This study analyzed the effects of foliar spraying of brassinolide (BR) at concentrations of 0.05, 0.1, 0.5, and 1 mg/L on the chlorophyll index, nitrogen balance index, quality, antioxidant defense system, and secondary metabolite profiles in leaves of Camellia sinensis cv. Fuding-dabaicha grown at 4 °C for 48 h. All exogenous BR treatments significantly increased leaf nitrogen balance index, with the highest effect at 0.1 mg/L, which also significantly increased leaf chlorophyll index. BR treatments distinctly increased tea polyphenol, catechin, amino acid, and caffeine levels at cold stress, with the greatest effect at 0.1 mg BR/L. Foliar spraying of BR showed no effect on the expression of CsGOGAT at cold stress, but it differentially regulated the expression of CsHMGR, CsGDH, and CsGs, accompanied by their expression being up-regulated under 0.1 mg BR/L treatment. BR-treated plants exhibited a low level of oxidative damage at cold stress based on malondialdehyde levels, which was associated with higher glutathione levels and CsCAT and CsSOD gene expression levels under BR concentrations of 0.05 mg/L and 0.1 mg/L. Non-targeted metabolomics found a total of 26,175 metabolites, the majority of which were lipids and lipid-like molecules (8.97%) and organic heterocyclic compounds (8.97%). BR treatments with 0.05, 0.1, 0.5, and 1 mg/L triggered 1181, 1997, 2414, and 1455 differential metabolites, respectively, accompanied by more differential metabolites being up-regulated. Among them, 18 differential metabolites were associated with tea quality. The enriched pathways of differential metabolites were mainly caffeine metabolism, amino acid synthesis and metabolism, alkaloid synthesis and metabolism, and flavonoid synthesis, depending on the BR concentrations used. Caffeine metabolism was an BR-inducible differential metabolite pathway. Taken together, foliar spraying of BR (0.1 mg/L) improved leaf antioxidant capacity and quality as well as modulated secondary metabolites and their pathways in cold-stressed tea. Full article

The production of cut flowers has substantial economic potential, and therefore, extending their lifespan has been the main focus of several floriculture researchers. Despite the increased marketable value of gladioli, their spikes rapidly lose their visual value and postharvest quality, accompanied by a short vase life. Unfortunately, most floral preservatives used to extend the flower lifespan have hazardous impacts; thus, providing eco-friendly alternatives has spurred immense interest among scientists. Sage and rosemary essential oils (EOs) seem to be effective eco-friendly flower preservatives due to their content of antimicrobial and antioxidant compounds. This study was therefore conducted to investigate whether using sage or rosemary EOs as novel preservative solutions can enhance the quality and prolong the vase life of cut gladiolus spikes. Gladiolus spikes were subjected to several concentrations (0, 50, 100, 150 and 200 mg L⁻¹) of sage or rosemary EOs in a vase solution. All levels of both EOs significantly prolonged the vase life of gladiolus spikes, increased their water uptake and enhanced floret opening compared to the control. The vase life was increased by 88.16 and 84.76% by applying 150 or 100 mg L⁻¹ of sage or rosemary EOs, respectively, compared to the untreated spikes. Sage and rosemary EO treatments markedly decreased bacterial populations, preserved the chlorophyll content, decreased H₂O₂ production and retarded the accumulation of malondialdehyde (MDA), and therefore preserved the membrane stability relative to the control. Furthermore, the total phenols and the antioxidant enzyme activities of catalase, glutathione reductase and ascorbate peroxidase were significantly increased due to sage or rosemary EO applications. In conclusion, sage or rosemary EOs may be applied as innovative, eco-friendly alternative preservatives to the communal chemicals used as preservatives in the cut flower industry. Full article

Programmed cell death (PCD) is common in plant growth and development, such as xylem development, organ senescence, and abscission. Calyx abscission in Korla fragrant pear contributes to fruit quality, while it was not clear whether PCD occurred during calyx abscission and which signals regulated the process. Therefore, it is imperative to clarify the process of PCD in the process of calyx abscission in Korla fragrant pear under natural conditions to enrich the mechanism of calyx abscission. The results showed that the total time of calyx abscission of Korla fragrant pear began from 6 days after pollination (DAP) to 13 DAP, and the peak of calyx abscission occurred 10 DAP. During the whole process of calyx abscission, PCD started 6 DAP. At 9 DAP, the degree of PCD deepened. At 12 DAP, the cells in the abscission zone showed asymmetry on both sides, the organelles in the distal cells of the abscission zone degraded into apoptotic fragments, and the protective layer of the normal development of cells located at the proximal end of the abscission zone region ended the PCD process. ETH concentrations in the abscission zone of the decalyx fruit were significantly higher than those of the persistent calyx fruits in each period during calyx abscission, and high levels of ethylene and hydrogen peroxide and low contents of the GA₃, ZT, and hydroxyl radicals promoted calyx abscission before the formation of the abscission zone. At 3 DAP, the ethylene concentration (43.97 ppm) and H₂O₂ content (8.49 μmol/g) of decalyx fruit in the abscission zone were significantly higher than those of persistent calyx fruit by 67.69% and 27.86%, respectively; however, the GA₃, ZT, and hydroxyl radicals showed the opposite. Overall, PCD in the abscission zone of decalyx fruits did occur during the calyx abscission of Korla fragrant pear, and ethylene and H₂O₂ might play major roles in initiating the PCD process during Korla fragrant pear calyx abscission. Full article

The Lycoris radiata (L’ Herit.) Herb. is a perennial bulbous plant characterized by its high ornamental and medicinal value, exhibiting a unique growth rhythm where the flower and leaf do not coexist and a period of summer dormancy. However, its metabolic response to various developmental stages remains unclear. To address this gap, we conducted a non-targeted metabolomic analysis spanning six developmental stages of L. radiata. The results showed that most differentially accumulated metabolites (DAMs) demonstrated enrichment predominantly in carbohydrate and amino acid metabolism pathways, with the former being more active during vegetative growth and the latter during reproductive stages. The proportion of DAMs categorized under “quaternary ammonium salts”, “tricarboxylic acids and derivatives”, “fatty acids and conjugates”, and “pyrimidine nucleotide sugars” was notably higher in comparisons between the flowering and dormancy stages than in other comparative groups. Furthermore, DAMs involved in the KEGG pathways of C5-branched dibasic acid metabolism and lysine biosynthesis were uniquely identified during the transition from Dormancy to Flowering. The proportion of DAMs associated with “linoleic acids and derivatives” and “pyridines and pyridine derivatives” was notably higher in the leafing out versus flowering comparison than in other comparative groups. Furthermore, the glycolysis/gluconeogenesis pathway was uniquely enriched by DAMs during this phase. This study provided an in-depth view of metabolite changes in L. radiata over its annual growth cycle, enriching our understanding of the regulatory mechanisms governing its development, dormancy, and flowering. Full article

Heterodera schachtii (Schmidt, 1871) (Nematoda: Heteroderidae) is one of the most widespread plant-parasitic nematodes (PPNs) associated with cabbages, which cause severe yield losses in cruciferous vegetables. This study aimed to improve the current understanding of the prevalence and detection of H. schachtii in the cabbage-growing areas of Niğde Province, Türkiye. Field surveys were conducted between November and December 2021, and 100 soil samples were collected immediately after cabbage harvesting. Heterodera schachtii populations were identified by morphological and morphometric methods along with Internal Transcribed Spacer of the ribosomal region (ITS-rDNA) and Cytochrome Oxidase Subunit (COI-mtDNA) sequencing. The mean body length of H. schachtii was 463 ± 7 μm, while stylet and hyaline length ranged between 20.7–27.8 μm and 20.1–32.1 μm, respectively. Nearly half of the surveyed areas were infested with H. schachtii with a 41% incidence rate. However, the Merkez District had the highest proportion of infested fields with an over 51% incidence rate. The population density was determined in 41 samples with a mean of 79.5 cysts per 250 g of soil. These results will help to determine the control and management strategies of H. schachtii. Full article

Fusarium wilt in Cymbidium ensifolium, caused by Fusarium oxysporum, is highly contagious and poses a severe hazard. It significantly reduces the ornamental value of C. ensifolium and causes substantial economic losses in agricultural production. Nucleotide-binding site–leucine-rich repeat (NBS-LRR) genes are key regulatory factors in plant disease resistance responses, playing vital roles in defending against pathogen invasions. In our study, we conducted a comprehensive analysis of the NBS-LRR gene family in the genome of Cymbidium ensifolium. Phylogenetic analysis identified a total of 31 NBS-LRR genes encoding NB-ARC proteins, which were categorized into five classes (CNL, CN, NL, N, RNL) based on their protein structural domains. These genes were found to be unevenly distributed across eight chromosomes. Physicochemical analysis revealed significant variances in molecular weight and sequence length among the family members. Subcellular localization results indicated that most genes primarily reside in the cytoplasm and cell membrane, suggesting that the primary sites of disease resistance responses may be the cell membrane and cyto-plasm. Furthermore, noticeable disparities were observed in gene structures and conserved motifs among different categories of family genes. Promoter analysis indicated that cis-regulatory elements are mainly associated with plant stress, jasmonic acid, gibberellin, and other development-related factors, suggesting that CeNBS-LRR genes mainly resist external stress through hormones such as abscisic acid and jasmonic acid. We characterized twenty-seven CeNBS-LRR gene expression patterns of healthy C. ensifolium at different periods after Fusarium wilt infection, and found that those genes exhibit a temporospatial expression pattern, and that their expression is also responsive to Fusarium wilt infection. By analyzing the expression pattern via transcriptome and qRT-PCR, we speculated that JL006442 and JL014305 may play key roles in resisting Fusarium wilt. This study lays the groundwork and holds considerable significance as a reference for identifying disease-resistant genes and facilitating genetic breeding in C. ensifolium. Full article

Five edible species of the genus Kaempferia—K. minuta, K. phuphanensis, K. sisaketensis, K. takensis, and K. udonensis—in Thailand were cytologically studied by their root tips. The somatic chromosome numbers of all species were found to be 2n = 22, and the FNs of all species were revealed to be 44. The karyotype of all five rare and endemic species was provided: 10m + 12sm with three satellites for K. minuta, 12m + 10sm with six satellites for K. phuphanensis, 18m + 4sm with four satellites for K. sisaketensis, 6m + 10sm + 6st with three satellites for K. takensis, and 14m + 2sm + 6st with two satellites for K. udonensis. This research identified all new karyological information regarding the chromosome number, FN, karyotype, and ideogram of all the species. They all had a symmetrical karyotype. The chromosome structures and karyotype formula of five edible Kaempferia species from Thailand can be used for species identification. Full article

Wild edible plants, botanically defined as phytoalimurgical species, have historically been a useful source of food to cope with recurrent famines and poor farming conditions. If properly identified, harvested, transformed and promoted, alimurgical plants could further enhance the wellbeing of rural and urban communities and the multifunctional productivity of agriculture. The research aimed to survey alimurgical species in a wetland, map their location, detect their spatial richness, and develop a monitoring plan for ongoing vegetation succession. The study area is the King’s Lagoon, a wetland that has recently undergone a radical restoration of its natural layout. A satellite image was used to create a land cover map and interpret the relationship between plant species and land cover. The survey provided a snapshot of the wetland’s current ecosystem status and used botanical analysis and ecological indices to investigate biodiversity levels. The alpha, beta and gamma levels of biodiversity were explored and interpreted through the statistical processing of a comprehensive dataset of species occurrence and abundance, together with the calculation of Shannon’s, Simpson’s and Jaccard’s indices. It was observed that biodiversity in the wetland is developing gradually following restoration and is expected to increase over time as successional stages take hold. Biodiversity is more pronounced along the banks of the canals and watercourses connecting the basins and open ponds, while it is less pronounced in areas where the soil has been disturbed by previous excavations. Salicornia spp., Beta vulgaris subsp. maritima and Suaeda vera were identified as the most common and interesting species found in the study area. The potential for cultivation of some of the halophyte species that were monitored was also highlighted, with particular reference to the selection of the most commercially interesting species, the best species associations and intercropping practices in a wetland context, which must always prioritize the conservation of wild biodiversity. The spring surveys should be repeated in the coming years in order to accurately trace the dynamics of the ecological succession of this particular ecosystem, once it has returned to its natural development. Full article

(1) Background: Since microplastics in aquatic environments are difficult to prevent and can cause adverse physiological and biochemical reactions to various organisms, we aimed to analyze the effectiveness of using aquatic plants with well-developed roots and excellent water purification capabilities to remove microplastics in an eco-friendly manner. Additionally, we examined the differences in removal efficiency based on the sizes of the microplastic particles and the types of aquatic plants used. (2) Methods: Two types of polyethylene (PE) microplastic particles (46 µm and 140 µm) and two types of aquatic plants (Iris pseudacorus and Lythrum anceps) were used in this study. These plants were cultivated in tap water containing microplastics for a duration of four months in an aquatic setup without soil. Water samples from the cultivation area were analyzed using Fourier-transform infrared spectroscopy (FT-IR) to determine the reduction in microplastics. Scanning electron microscopy (SEM) was employed to examine the adsorption of microplastics on the plants’ roots. Plant growth was assessed by measuring plant height, plant width, and the number of branches (number of leaves). (3) Results: The results revealed significant reductions in the numbers of microplastics in the water of the cultivation boxes containing Iris pseudacorus and Lythrum anceps, irrespective of the microplastic particle size or plant type. These reductions were further confirmed by the adsorption of microplastics on the roots of both plant species. Moreover, the presence of microplastics had no significant negative effects on the plants’ growth. These findings suggest that Iris pseudacorus and Lythrum anceps are suitable plants for removing microplastics in aquatic environments. (4) Conclusions: To effectively reduce aquatic microplastics using plants, it is essential to establish a sustainable vegetation cover using perennial plants with well-developed roots and rapid reproductive capabilities. Follow-up research should consider not only the type of plant but also various aspects related to their tolerance to different environmental conditions. Full article

Despite the increasing attention on smart farms as a solution to rural issues such as aging agricultural populations, a shortage of young farmers, decreased production area, and reduced investment leading to stagnant income, exports, and growth rates, many farms still rely on traditional methods like cultivating tangerines in open fields. Despite this, increasing farm income requires producing high-quality tangerines and selling them at premium prices, with fruit sweetness being a crucial factor. Therefore, there is a need to examine the close correlation between tangerine quality and sweetness. In this paper, we use deep learning with the PyCaret library to predict and analyze tangerine sweetness using data from seven regions in Jeju and 13 comprehensive factors influencing sweetness, including terrain, temperature, humidity, precipitation, sunlight, wind speed, acidity, sugar-acid ratio, and others. Although applying all 13 factors could achieve over 90% accuracy, our study, limited to seven factors, still achieves a respectable 82.4% prediction accuracy, demonstrating the significant impact of weather data on sweetness. Moreover, these optimistic predictions enable the estimation of tangerine quality and price formation in the market for the coming year, allowing tangerine farmers and related agencies to respond to market conditions proactively. Furthermore, by applying these data to smart farms to control factors influencing tangerine sweetness, it is anticipated that high-quality tangerine production and increased farm income can be achieved. Full article

The storage roots of orange-fleshed sweet potato contain high levels of polyphenols and carotenoids. Little information is available on changes in the content and composition of these secondary metabolites during the growth stages of the root system. We investigated changes in carotenoids, polyphenols, and anthocyanins in the root system of the orange-fleshed sweet potato ‘Tamaakane’ from the post-planting stage. Carotenoids and polyphenols accumulated immediately after root-system formation at 15 days after transplanting (DAT). The levels of carotenoids increased by 45 DAT and decreased once the storage root enlargement began, but increased rapidly thereafter. After 90 DAT, β-carotene accounted for >90% of the total carotenoids, and the frequency remained stable until maturity. Total polyphenol content increased significantly towards 45 DAT and then gradually decreased as the storage roots began to thicken. No anthocyanin was detected in the root systems of ‘Tamaakane’ at any stage. The content and composition of these secondary metabolites are discussed in terms of agronomic aspects, as they might contribute to a strategy to protect storage roots while engaging with each other against biotic or abiotic stresses at the growth stage of the root system. Full article

Potassium is an essential mineral nutrient for citrus growth and stress response. In this study, the HAK/KUP/KT gene family was identified from the genome of trifoliate orange (Poncirus trifoliata). The physical and chemical properties, chromosomal location, gene structure, evolutionary relationship, conserved motifs, and tissue expression characteristics were analyzed. The expression characteristics under low potassium and salt stress were analyzed by fluorescence quantitative PCR. The function of PtKUP10 was investigated by heterologous expression in Arabidopsis thaliana. The results showed that at least 18 PtKUPs were distributed in seven chromosomes. Phylogenetic analysis showed that four PtKUPs clustered in clade I, which mediated the high-affinity potassium absorption. Gene expression analysis showed that four PtKUPs were highly expressed in root, seven PtKUPs were up-regulated by low potassium stress, and nine PtKUPs were up-regulated by salt stress. The cis-acting elements on the promoter of PtKUPs were predominantly involved in stress and hormone responses. Overexpression of PtKUP10 in Arabidopsis thaliana could enhance salt tolerance by accumulating more potassium in the shoot and reducing sodium content in the shoots and roots. These results indicated that PtKUPs play important roles in potassium absorption and salt stress response, and PtKUP10 might enhance salt tolerance by maintaining potassium and sodium homeostasis. Full article

Oligosaccharides, as a wide type of polysaccharide, have a broad antimicrobial spectrum and promote development as plant growth stimulants. To investigate the regulation effects of different oligosaccharides on the dynamic changes of chlorophyll content, leaf fluorescence, root activity and morphology, and chloroplast ultrastructure, as well as the yields and yield components of strawberry and cucumber, typical greenhouse experiments were conducted over two years (2021–2022). The experimental plants were foliar sprayed with tap water (CK), chitosan oligosaccharide (CSOS), and mixed oligosaccharides (MixOS) five times before flowering. The conventional management (CM) was conducted as a conventional control. The findings of the present study suggest that the application of MixOS has the greatest regulation effects on delayed leaf senescence, well-developed roots, and higher fruit productions of strawberry and cucumber. Exogenous MixOS resulted in significant increases in SPAD values, maximum photochemical efficiency (Fv/Fm), and photochemical quenching coefficiency (qP); they were increased by 1.94–28.96%, 5.41–33.89%, and 9.93–62.07%, compared to the CSOS, CM, and CK treatments, respectively. The orderly and steady structure of thylakoids in the chloroplast, and the randomly distributed starch grains, could be clearly observed in the MixOS treatment, while the non-photochemical quenching (NPQ) was correspondingly reduced by 19.04–45.92%. Meanwhile, the remarkable promotion of root activity and root surface morphology indicators (i.e., root length, surface area, average diameter, and volume) could be observed when exposed to the MixOS treatments, and the total yields of strawberry and cucumber were all increased by 12.40–25.57%. These findings suggest that the mixed oligosaccharides mainly promote the coordinated growth of root and shoot, which leads to the improved yields of strawberry and cucumber. Full article

Integrated pest management (IPM) aims to protect plants using methods that limit the use of pesticides, as well as other interventions, to levels that are economically and ecologically justified, thus reducing the negative impact of crop protection on humans and the environment [...] Full article

Reactive oxygen species (ROS) are pivotal in signal transduction processes in plant–pathogen interactions. The ROS signaling pathways involved in Candidatus Liberibacter asiaticus (CLas) and Xanthomonas citri subspecies citri (Xcc) infections in Citrus sinensis (sweet orange) are unclear. In this study, we comprehensively identified ROS metabolism-associated genes, including 9 NADPH oxidase (RBOH), 14 superoxide dismutase (SOD), 1 catalase (CAT), 9 peroxiredoxin (PrxR), 5 ascorbate peroxidase (APX), 4 glutathione peroxidase (GPX), 3 monodehydroascorbate reductase (MDAR), 2 dehydroascorbate reductase (DHAR), 2 glutathione reductase (GR), 24 thioredoxin (Trx), and 18 glutaredoxin (GLR) genes in C. sinensis. An analysis revealed variable gene structures but conserved motifs and domains in ROS subfamilies. A comparative synteny analysis with Arabidopsis thaliana and Vitis vinifera indicated evolutionary conservation of most ROS metabolism-associated genes, with some originating from gene duplication events post-species divergence in C. sinensis. Expression profiling revealed five up-regulated genes and four down-regulated genes during both CLas and Xcc infections. Promoter analysis revealed numerous stress-responsive elements in the promoter of ROS metabolism-associated genes. Protein–protein interaction network analysis highlighted the involvement of ROS metabolism in various biological processes. A comparison of ROS metabolism-associated genes between C. sinensis and Poncirus trifoliata indicated multiple gene gain and loss events within ROS subfamilies of C. sinensis. This study enhances our understanding of ROS metabolism in C. sinensis and sheds light on citrus–pathogen interactions. Full article

Fruit storage is optimized at the lowest safe temperature to maximize storage life whilst avoiding chilling or freezing injury. The few published studies of freezing in kiwifruit (Actinidia spp.) have been conducted with A. chinensis var. deliciosa ‘Hayward’ fruit, with freezing temperatures reported in the range of −1.5 °C to −2.5 °C. In China, a large number of kiwifruit cultivars have been commercialized recently, with at least ten being commonly planted. In this research, freshly harvested fruits from 45 kiwifruit germplasm accessions were measured for freezing point, soluble solids content (SSC) and water content (WC). The difference in freezing point of different tissue zones within a fruit and after different periods of cold storage were determined for the fruit of three representative main cultivars: the green-fleshed ‘Hayward’, the red-fleshed A. chinensis var. chinensis ‘Donghong’, and the yellow-fleshed interspecific hybrid A. eriantha × A. chinensis ‘Jinyan’. The the freezing point of kiwifruit was found to be highly correlated with the SSC. This relationship was found irrespective of whether the measurement was made at harvest, at different places in the fruit, or after ripening during storage. These findings agree with previous reports for kiwifruit and other fruits, although it appears that the relationship may differ among kiwifruit cultivars, something not previously reported and which requires further confirmation. Full article

Τhe production of fresh fruit as well as olive orchards is increasing around the world, in order to meet the global demand for both fruits and olive products. This results in the spread and establishment of fruit and olive tree cultivation in areas where they were not found before, for example, plains and lowlands prone to waterlogging. Climate change is having a significant impact on the natural environment. Agricultural open-field crops have less growth and yield under these harsh weather conditions. Nowadays, unpredictable rainfall more often exposes field crops to waterlogging on a regular basis. This is a very stressful factor which can cause a reduction in yield and even total crop elimination. In this review, the morphological and physiological parameters affected by waterlogging are developed in order to understand better how olive and other fruit crops respond to waterlogging conditions and how this affects their development and productivity. Having a better understanding of these mechanisms can help us design strategies and approaches to increase fruit crop resistance to waterlogging stress. Full article

Salicylic acid (SA) is known to be an efficient elicitor of secondary metabolism in plants. Arbutin, a characteristic phenolic glycoside found in ‘Yuluxiang’ pear (Pyrus bretschneideri Rehder × Pyrus sinkiangensis Yu), is widely used in lightening agents, in addition to cough, anti-inflammatory, and anti-microbial remedies, among other applications. However, research into the synthesis of arbutin in pear is limited. This study aimed to clarify the effect of exogenous SA on the arbutin content of pear using HPLC and investigate the mechanism for arbutin accumulation using RNA-Seq analysis. HPLC revealed that SA increased the arbutin contents of leaf, fruit, and callus in pear and demonstrated that the effect of SA is concentration and time dependent. RNA-Seq analysis of pear callus treated with or without SA revealed 380 differentially expressed genes (DEGs), 335 of which were up-regulated. According to a KEGG database analysis, the highest number of genes were annotated for phenylpropane biosynthesis. Overall, 21 DEGs were found to be involved in the synthesis of hydroquinone and UDP-glucose, which are substrates of arbutin synthesis. It is noteworthy that the expression levels of three up-regulated genes (Pbr006844.1, Pbr021064.1 and Pbr021069.1) related to hydroquinone glycosyltransferase were induced by SA and hydroquinone. Furthermore, transient overexpression of PbUGT72B1 (Pbr021069.1) increased the arbutin content in pear callus. These data explain the regulation of gene transcription associated with the promotive effect of SA on arbutin biosynthesis in pear, thus providing a theoretical foundation for enhancing the arbutin content of fruit through genetic engineering. Full article

The health of soil is paramount for sustaining life, as it hosts diverse communities of microorganisms that interact with plants, influencing their growth, health, and resilience. Beneficial microorganisms, including fungi and bacteria, form symbiotic relationships with plants, providing essential nutrients, promoting growth, and enhancing stress tolerance. These microorganisms, such as mycorrhizal fungi and plant growth-promoting bacteria, play crucial roles in nutrient cycling, soil health, and plant productivity. Additionally, they help lessen reliance on chemical fertilizers, thereby mitigating the environmental risks associated with their use. Advances in agricultural practices harness the potential of these beneficial microorganisms to improve crop yields while minimizing the environmental impact. However, challenges such as competition with indigenous microbial strains and environmental factors limit the universal utilization of microbial inoculants. Despite these challenges, understanding and leveraging the interactions between plants and beneficial microorganisms hold promise for sustainable agriculture and enhanced food security. Full article

As a consequence of climate change, temperature and rainfall regimes are being modified, threatening the survival of the current gardening concept in many areas of the world. This situation highlights the need to investigate the potential of other species, especially in more sensitive areas such as the Mediterranean Basin. The aim of this research is to study the resilience of adapted species to promote sustainable gardening. To achieve this, seven species belonging to three families (Amaranthaceae, Lamiaceae and Asteraceae) used or potentially used as ornamentals were selected to compare their tolerance at the germinative stage to different levels of temperature (10 °C to 35 °C) and water stress created by PEG 6000 (−0.10 MPa to −2.5 MPa). Germination percentage, mean germination time, base temperature, thermal time, base water potential and hydrotime were calculated. The results showed a good response to high temperature and low osmotic potential in most of the species, and germination even increased under certain stress levels. Salsola oppositifolia presented by far the best results in terms of germination under high-water-stress conditions and the second best at high temperatures. The extraordinary response of Celosia argentea, an alien species, highlighted the risk of it becoming an invasive species. Full article

The study of pear dormancy mechanisms is currently a major research area in pear production and has high economic significance for agricultural production. We selected the southern sand pear cultivar Pyrus pyrifolia ‘Huanghua’ as the test material to study the pear dormancy process through microscopic observation of pear flower buds. The endodormancy period is abbreviated as D_bud. Similarly, the endodormancy release initiation period and the ecodormancy period are referred to as DB_bud and G_bud, respectively. Meanwhile, RNA sequencing was used to obtain the gene expression profile of Pyrus pyrifolia ‘Huanghua’ flower buds. The RNA sequencing results indicated that there were 224 differentially expressed genes (DEGs) in endodormancy (D) vs. endodormancy release initiation period (DB), while 975 were identified between endodormancy and ecodormancy (G). Finally, a total of 868 DEGs were found in the DB vs. G comparison. The expression levels of the genes Pbr009498.1 (LAX1-1), Pbr012348.1 (LAX1-2), Pbr021158.1 (GH35), and Pbr031621.1 (LAX2) encoding IAA were significantly higher during the DB_bud than during the D_bud. The expression level of Pbr025864.2 (IAA13) during the D_bud was significantly higher than the DB_bud and G_bud. The Pbr041942.1 (GID1B) gene also showed a significant increase during ecodormancy. Taken together, these results suggest that these genes, annotated as LAX1, GH35, LAX2, IAA13, and GID1C, are involved in endodormancy maintenance and in the transition from endodormancy to ecodormancy in Pyrus pyrifolia ‘Huanghua’. Full article

Climate change exacerbates drought, globally impacting crop production and necessitating the adoption of sustainable strategies. This study investigates the potential synergistic effects of salicylic acid (SA) and Bacillus butanolivorans KJ40 (KJ40) on napa cabbage (Brassica rapa subsp. pekinensis) under water-deficit stress conditions by watering withheld for five days. Results demonstrate that the combined application of KJ40 and SA, particularly at concentrations of 0.5 mM and 1 mM, significantly enhances plant growth and mitigates the negative impacts of water deficit. Moreover, the combination treatment with SA (0.5 mM) and KJ40 (1 × 10⁸ cells/mL) reduces lipid oxidation and enhances antioxidant enzyme activity, indicating improved plant stress tolerance. Analysis of soil microbial profiles reveals alterations in metabolic activity and substrate utilization patterns, suggesting potential changes in rhizosphere dynamics. Additionally, this study examines the impact of SA on KJ40 population dynamics in soil, revealing concentration-dependent effects on bacterial survival. Overall, the combination of KJ40 and SA was effective in mitigating water-deficit stress in napa cabbage. These findings highlight the combination as a novel synergistic strategy to enhance plant resilience to water-deficit stress, offering insights into plant–microbe interactions and soil ecosystem dynamics. Full article

Floral scent is an essential and genetically complex trait in herbaceous peonies (Paeonia lactiflora Pall.); however, specific genes related to metabolic and regulatory networks remain scantily studied. Our study integrated metabolite profiling and RNA-sequencing to screen floral scent biosynthetic genes. Hence, the major molecules identified by headspace collection combined with cultivar-specific GC-MS analysis were geraniol, β-caryophyllene, 2-phenylethanol (2-PE), citronellol, and 1,8-cineole. Genes related to terpenoids and 2-PE biosynthesis were identified after the assembly and annotation of the P. lactiflora transcriptomes. Eight angiosperm-specific terpene synthases (TPSs) from the TPS-a and TPS-b clades, as well as enzymes linked to 2-PE synthesis such as aromatic amino acid decarboxylase (AADC), phenylacetaldehyde reductase (PAR), and geranial reductase (GER) were identified. The biochemical analysis of the enzymes encoded by PlPAR1 and PlGER1 generated 2-PE from phenylacetaldehyde (PAld). The pairwise alignment of AADC1 reveals a splice variant lacking a 124 bp fragment, thus highlighting the possible role of alternative splicing in modulating floral scent composition. This study offers insights into the molecular-level biosynthesis of terpenoids and 2-PE in Peonia taxa, and provides the basis for the functional characterization, breeding, and bioengineering of prospective candidate genes for the production of floral volatiles in the Paeonia genus. Full article

Due to the high respiration rate and ethylene production at the cut surface of bamboo (Dendrocalamus latifloxus Munro) shoots after harvesting, browning and lignification at the cut surface reduce their quality and shelf life. Due to the demand of consumers, using physical treatment to inhibit microbial growth and maintain quality has become more and more popular. In this study, bamboo shoots were treated with hot water at 70 °C for 30 s after harvesting and then stored at 1, 3, or 5 °C for 4 weeks to measure the quality change. Our results show that the L* value and h° angle at the cut surface of the bamboo shoots were significantly higher, but the respiration rate was significantly lower when stored at 1 °C compared with those at 3 and 5 °C. In terms of quality, the bamboo shoots showed lower firmness and cutting force values, and no decay was observed at 1 °C. The results from the shelf simulation test with rewarming of the cold-treated bamboo shoots at ambient temperature (25 °C) for 1 day indicated that the L* value and h° angle were significantly higher for the bamboo shoots stored at 1 °C compared with those stored at 3 and 5 °C. Taken together, browning and lignification at the cut surface were effectively inhibited, quality was maintained, and the storage life could be extended to 4 weeks at 1 °C. Full article

Mealy peaches are dry and flavorless, which reduces their consumer acceptance. A deeper understanding of the mechanism underlying mealiness is crucial to enhancing peach fruit quality. In this study, comparative profiling was conducted on CP13, CP14, CM, and RM peaches. Sensory evaluation indicated that CP13 and CM are non-mealy clingstone and freestone peaches, respectively, and CP14 and RM are mealy freestone peaches. Both CP13 and CP14, identified as stony hard (SH) peaches, exhibited minimal ethylene release, whereas CM and RM, identified as melting flesh (MF) peaches, released high amounts of ethylene during the ripening process. Scanning electron microscopy (SEM) microstructure observation indicated that cells in the flesh tissue of mealy peaches, CP14 (SH) and RM (MF), were intact and separated, with large intercellular spaces and irregular arrangements. The main factor that promotes mealiness is differences in pectin metabolism, which impact cell wall composition. The fluctuations in polygalacturonase (PG) and pectin methylesterase (PME) activity between mealy and non-mealy peaches were the main factor contributing to mealiness. However, the changes in cell wall metabolism that caused these fluctuations did not have a clear direction. Using transcriptome analysis and weighted gene co-expression network analysis (WGCNA), we were able to identify forty differentially expressed genes (DEGs) that are associated with mealy patterns. Among these DEGs, genes encoding PG were significantly upregulated in mealy peaches (CP14 and RM) compared to non-mealy peaches (CP13 and CM). PpPG1 was the main effector gene for mealiness, while PpPG2, PpEGase2, PpEXP1, PpEXP3, PpAGP2, PpIAA4, and PpABA2 were identified as candidate genes regulating peach mealiness. These findings provide a solid experimental basis for understanding the textual distinctions between mealy and non-mealy peaches. Full article

Sweet pepper is a crop that benefits from phytosanitary treatments with low environmental impact, especially the successful control of pests through the introduction of biological control agents in greenhouses. However, predators that naturally occur in these surroundings often enter greenhouses. The precise roles of these natural predators and their interactions with the introduced predatory insects and mites are often unknown. This study investigated the relationships between Nesidiocoris tenuis, which is naturally present, and Amblyseius swirskii and Orius laevigatus, which are two species of generalist predators released for the control of multiple pests. This study was conducted for two years on 13 commercial sweet pepper crops in various types of greenhouses (tunnels and traditional greenhouses) in Sicily. The environmental complexity value (ECV) for each site was estimated based on 18 points detected around the site according to the different habitats that occurred at each coordinate. The results showed that the occurrence of N. tenuis in greenhouses, independently of their typology (tunnel or traditional greenhouse), was mainly promoted by the greater diversification of habitats immediately surrounding the pepper crops (in a circular area with a diameter of 500 mt), with an increase in its density during the crop season. Moreover, N. tenuis–O. laevigatus’s co-occurrence in flowers suggested that they were not impacted by each other’s presence and that their co-occurrence had a significant effect on pest reduction, although their co-occurrence was density-dependent. As an intraguild predator, N. tenuis competed with O. laevigatus for Frankliniella occidentalis when many predators were present. In addition, N. tenuis also competed with A. swirskii when they both occurred in flowers at a higher density. This study highlights the importance of pepper plant flowers in promoting a higher occurrence of juvenile forms of N. tenuis within flowers. Amblyseius swirskii colonized the plants in 3 weeks, distributing itself almost uniformly over the leaves with a clear control action against not only Bemisia tabaci but also F. occidentalis when present on the flowers. Thus, this concurrent analysis of several commercial pepper sites within the same production area suggests that, even with similar pest control plans, the diverse variability in the presence of natural enemies must be considered when selecting control strategies for pepper crop pests and that N. tenuis, favored by complex surrounding habitats, contributes actively to pest reduction. Full article

Ficus is a significant genus within the Moraceae family, primarily native to tropical and subtropical regions. It plays a crucial role in the study of co-evolution and genetics in the fig–fig wasp symbiosis. Advancements in sequencing technology have facilitated whole-genome sequencing of several Ficus species, accumulating vast amounts of genomic and transcriptomic data available in public databases. To streamline data integration, display, and analysis, we developed the Ficus Genome Database (FGD), a consolidated platform for the genomic data of five Ficus species, and self-assembled transcriptome data for 24 fig ostiolar bracts. The FGD is currently home to a diverse array of data, encompassing genome and gene sequences, annotations of genes, transcriptome analyses, biochemical pathways, non-coding RNA, and findings from comparative genomic studies, such as collinear blocks across different Ficus genome assemblies. To enhance translational and practical research concerning Ficus, FGD provides an extensive suite of accessible query interfaces, analytical instruments, and visualization options. These include the NCBI BLAST sequence search tool and the JBrowse/GBrowse genome browser. FGD also offers several distinct tools, including a genome Synteny Viewer, expression heatmap display, gene family identification, Gene Ontology terms enrichment, and pathway enrichment analysis. Full article

An experiment was conducted with two-year-old ‘Fino 95’ lemon plants (Citrus limon Burm. f. cv. Fino) grafted on C. macrophylla (Citrus macrophylla Wester) to study the effects of salinity on plants inoculated with arbuscular mycorrhizal fungi (AMF). Half of the inoculated (+AM) and non-inoculated (−AM) plants were irrigated with half-strength Hoagland solution, and the remainder were inoculated with half-strength Hoagland solution + 30 mM NaCl. Ninety-eight days later, results showed that AMF had alleviated the negative effect of salinity on growth. Inoculation with AMF provided some protection against the damage that salinity caused on cellular membranes and improved the plant water status and turgor under saline conditions (Ψ_x and Π increased by 16% and 48%, respectively). The responses of mineral nutrition to salinity and AMF treatments were complex. P concentrations in the leaves and roots of +AM plants were lower than in those of −AM plants, but inoculation improved Ca²⁺ (by 20%), Mg²⁺ (24%), Fe²⁺ (21%), and Zn²⁺ (7%) nutrition in roots and also the Mg²⁺/Na⁺ ratio in leaves (33%), reducing the antagonistic effect of Na⁺ on Mg²⁺ nutrition in salt-treated plants. AMF could protect plants against salt stress through the maintenance of the gas exchange capacity and due to a better antioxidant response. All these positive effects of AMF contributed to mitigating the harmful effects of salinity stress on the plant growth performance of lemon trees grafted on C. macrophylla rootstock under salinity conditions. Full article

In this study, the development trends of bioclimatic parameters recorded at the Maribor and Murska Sobota climate stations from 1952 to 2022 and the dynamics of grape ripening in early-, medium-, and late-ripening grape varieties in the Podravje wine-growing region in Slovenia (north-eastern Slovenia) from 1980 to 2022 were investigated. Based on the data on soluble solids content, total acidity, and the recommended harvest date per year (until the technological ripeness of the grapes; 76°Oe), trends for shortening the growing period of the vines were calculated. Temperature changes have been more pronounced since 1980. The number of so-called hot days (with a maximum of T > 30 °C) has increased the most, which has the greatest impact on other bioclimatic parameters, e.g., the average temperature and growing degree days (GDDs) and the Huglin index (HI). For the period of 1980 to 2022, the trends were 0.44 °C (Murska Sobota) and 0.51 °C (Maribor) per decade, respectively. The trends were more pronounced for the average temperature in the period of May–June (TMJ). After 1980, the HI increased by about 10 units per year. As a result of the climate warming, grapes in north-eastern Slovenia ripened 26 (‘Sauvignon Blanc’) to 35 (‘Welschriesling’) days earlier. The trends showed a decrease in total acidity, which can be attributed to the higher temperatures during the growing season period, especially during the ripening period of the grapes (véraison). After 2010, the average temperatures during the growing season (1 April to 31 October) in Podravje were 1.6 °C higher than in the 1980s. In line with the earlier ripening of the grapes, the actual average temperature from 1 April to the harvest date was a further 1.0 °C higher. The higher temperatures in the late-ripening varieties ‘Riesling’ and ‘Furmint’ had a positive effect on the lower total acidity. Total annual precipitation and precipitation in the growing season for the period 1980 to 2022 in the Maribor area show decreasing trends of 6 mm/m² (p = 0.001) and 4 mm/m² (p = 0.012), respectively. In the eastern sub-wine-growing region of Podravje (Murska Sobota), the trends in precipitation were not significant. Full article

ZF-HD transcription factors, which are unique to land plants, are involved in the regulation of abiotic stress response and related signaling pathways, and play a crucial role in plant growth and development. Dendrobium is one of the largest genera of orchids, with a high ornamental and ecological value. However, the specific functions of the ZF-HDs in Dendrobium remain unknown. In this study, we identified a total of 53 ZF-HDs from D. chrysotoxum (17), D. catenatum (23), and D. huoshanense (13), and analyzed their physicochemical properties, phylogenetic relationships, chromosomal locations, protein structures, conserved motifs, and expression patterns. The phylogenetic relationships revealed that 53 ZF-HDs were classified into six subfamilies (ZHDI–V and MIF), and all ZF-HD proteins contained motif 1 and motif 4 conserved domains, while a minority of these proteins had exons. The analysis of cis-elements in the promoters of ZF-HDs from three Dendrobium species showed that growth- and development-related elements were the most prevalent, followed by hormone response and abiotic stress response elements. Through collinearity analysis, 14 DchZF-HDs were found to be collinear with DhuZF-HDs, and 12 DchZF-HDs were found to be collinear with DcaZF-HDs. Furthermore, RT-qPCR analysis revealed that DchZF-HDs play a regulatory role in the development of lateral organs during the flowering process. The results indicated that DchZHD2 plays a role in the unpigmented bud stage, while DchMIF8 and DchZHD16 play significant roles during the pigmented bud and initial bloom stages. Hence, this study provides a crucial basis for further exploring ZF-HDs functions in regulating the floral organs of orchids. Full article