International Journal of Plant Biology

The effect of Bacillus subtilis in combination with salicylic (SA) and jasmonic (JA) acids on the activity of amylases, cellulases, proteases, and their inhibitors in potato leaves in connection with the development of resistance to Phytophthora infestans (Mont.) de Bary in conditions of moisture deficiency have been investigated. Plants grown from microtubers were treated with Bacillus subtilis suspension (10⁸ cells/mL) and with a mixture of bacteria with SA (10⁻⁶ M), JA (10⁻⁷ M), and SA + JA and were then infected with P. infestans (10⁷ spores/mL) and cultivated under drought. Treatment with B. subtilis bacteria, especially in combination with signaling molecules, contributed to a decrease in the degree of pathogen infestation on plants grown with a lack of moisture. Both salicylate and jasmonate signaling pathways play an important role in the regulation of hydrolase activity and the stimulation of plant resistance. The revealed differences in the degree of hydrolase inhibitors activation under the influence of B. subtilis bacteria and signal molecules suggest different paths to the formation of resistance to P. infestans in potato under drought conditions. Full article

The protective effect of Bacillus bacteria against viruses can be significantly expanded by combination with salicylic acid (SA) or methyl jasmonate (MeJ). In soil water deficiency conditions, potato leaves were sprayed with Bacillus subtilis strain 47 combined with MeJ and MeJ + SA displayed a decrease in PVY and preservation of the shoot’s growth. Signaling molecules with Bacillus subtilis mitigated the adverse effect of PVY under water deficiency by manipulating enzymatic/non-enzymatic antioxidant levels and activity in treated plants. The application mixtures increased the mass and number of mini-tubers during the microclonal propagation of plants. Treatment with bacteria in combination with signaling molecules significantly changed the content and phosphorylation status of a number of hydrolases, catalase, phosphorylase, annexin, and protease inhibitor. Based on the analysis of changes in the proteome, the key mechanisms mediating the induction of plant resistance to change in the tuber proteome aimed at enhancing the expression of protective protein genes that increase resistance to pathogens and abiotic stress. Full article

Yam (Dioscorea spp.) is an important food security crop with economic, nutritional, and medicinal value. It is a source of carbohydrates for millions of people in tropical and sub-tropical regions of Africa, Asia, South America, the Caribbean, and the South Pacific Islands. Determining the appropriate parents for breeding programs is the most important decision that plant breeders must make to maximize genetic variability and produce excellent recombinant varieties. However, adequate genetic diversity and the population structure of yam accessions in Kenya are not available to guide accurate selection of parents for breeding. In the present study, 25 start-codon-targeted (SCoT) molecular markers were used to determine the genetic diversity and population structure among 20 yam accessions grown in Kenya. A total of 294 fragments were amplified, of which 95% were polymorphic with an average of 11.16 polymorphic fragments per primer. The polymorphic information content (PIC) value and primer resolving power (Rp) of 0.58 and 5.91, respectively, revealed high genetic diversity among the accessions. A dendrogram based on the unweighted pair group method of arithmetic means (UPGMA) grouped the 20 yam accessions into two clusters at 0.61 genetic similarity coefficients. Bayesian structure analysis revealed the existence of three subpopulations and some admixed accessions. Analysis of molecular variance (AMOVA) revealed a variance of 60% within the subpopulations and 40% among the subpopulations. The high degree of genetic diversity in the yam accessions successfully exhibited by SCoT molecular markers may serve as a valuable aid to widen the genetic base in yam breeding programs. The selection and hybridization of parental lines from the different clusters and sub-clusters identified could provide a foundation and could be exploited for yam breeding and variety development. Full article

The morphostructure of inflorescences in the genus Coelogyne Lindl. was studied for the first time using a structural–rhythmological approach. Three species of Coelogyne were used to describe one-season, intercalary, and all-season inflorescences. In C. monilirachis, a new type of all-season inflorescence was identified, characterized by a prolonged sympodial growth of the rachis, lack of a pronounced dormant period, and thickening of all rachis internodes except the first. This inflorescence has been determined to be a compound monochasial cyme, with each floral unit represented by a separate flower. C. ovalis has a one-season inflorescence, with the floral unit being a determinate bracteous spike (stachyoid), and C. prolifera developed intercalary inflorescences united in an indeterminate bracteous spike. Full article

Nowadays, the search for natural substances with a high nutraceutical effect positively impact the world market. Among the most attractive macromolecules are antioxidants, capable of preventing the development of various pathologies. Astaxanthin (ASX) is antioxidant molecule produced by the microalga H. pluvialis as a response to different types of stress. Usually, astaxanthin production involves the first phase of accumulation of the biomass of H. pluvialis (green phase), which is then stressed to stimulate the biosynthesis and accumulation of ASX (red phase). In this study, the H. pluvialis wild-type strain was subjected to random mutagenesis by UV. Among the different mutant strains obtained, only two showed interesting bio-functional characteristics, such as a good growth rate. The results demonstrated that the HM1010 mutant not only has a higher growth trend than the WT mutant but accumulates and produces ASX even in the green phase. This innovative genotype would guarantee the continuous production of ASX, not linked to the two-step process and the uniqueness of the product obtained. Full article

Hydrangea macrophylla is popular for its unique physiological characteristics and changeable colors. Previous studies have shown that the pH of the vacuoles of the sepal cells of hydrangea affects the color of the sepals. Located on the vacuolar membrane, NHX1 is an important H⁺ proton pump that drives the exchange of metal ions. This proton pump affects the physiological environment by controlling the accumulation of H⁺ in the vacuole. In hydrangea, the HmNHX1 gene has an open reading frame of 1626 bp and encodes a total of 541 amino acids. Bioinformatic analysis showed that HmNHX1, which encodes a Na⁺/H⁺ exchanger, is located on the vacuolar membrane. Tissue-specific expression analysis showed that the expression of this gene in the treatment group was higher than that in the control group. The ion flux in the vacuoles of colored hydrangea in the treatment group and the control group were measured, and the results showed that HmNHX1 was indeed a Na⁺/H⁺ exchanger. When the results of the HmNHX1 expression analysis and ion flux measurements are combined, it can be seen that HmNHX1 regulates the accumulation of H⁺ in the vacuole, ultimately affecting the color of the plant. Full article

Cryptostegia madagascariensis is an invasive plant species that covers 11% of the Brazilian northeastern territory, but its role on the litter trait in tropical ecosystems remains unclear. Here, we analyzed and compared the litter deposition, litter nutrient content, soil organic matter, and the litter decay rate from invaded and non-invaded environments by C. madagascariensis at a tropical Cambisol. The PCA analysis revealed that litter deposition, litter quality, and soil organic matter were correlated with the invaded environment. We grew plant species in greenhouse conditions to obtain a standard litter material to use in our litter bags in field conditions. We found that litter decay rate was higher in the invaded environment than in the non-invaded one. Our results suggest that C. madagascariensis changes litter traits in tropical ecosystems that in turn create negative plant–soil feedback to the native species by creating a physical barrier on soil surface and to promote its own rhizosphere. Full article

Plant colonization by endophytic bacteria is mediated by different biomolecules that cause dynamic changes in gene expression of both bacteria and plant. Phytohormones, in particular, salicylic acid, play a key role in the regulation of endophytic colonization and diversity of bacteria in methaphytobiome. For the first time it was found that salicylic acid influenced motility in biofilms and transcription of the surfactin synthetase gene of the endophytic strain Bacillus subtilis 26D in vitro. Treatment of Solanum tuberosum plants with salicylic acid, along with B. subtilis 26D, increased the number of endophytic cells of bacteria in potato internal tissues and level of transcripts of bacterial surfactin synthetase gene and decreased transcription of plant PR genes on the stage of colonisation with endophytes. Thus, the production of surfactin plays an important role in endophytic colonization of plants, and salicylic acid has an ability to influence this mechanism. Here we firstly show that plants treated with salicylic acid and B. subtilis 26D showed enhanced resistance to the late blight pathogen Phytophthora infestans, which was accompanied by increase in transcriptional activity of plant PR-genes and bacterial surfactin synthetase gene after pathogen inoculation. Therefore, it is suggested that salicylic acid can modulate physiological status of the whole plant–endophyte system and improve biocontrol potential of endophytic strains. Full article

DREB is a plant-specific transcription factor family that plays a pleiotropic regulatory role in response to abiotic stresses such as drought and cold. In this study, we identified 51 DREB genes of Camellia oleifera. These CoDREBs ranged from 88 to 518 amino acids (average/median 259/237 aa). The predicted molecular weights (MW) of the CoDREB proteins ranged from 9.7 kDa to 59.6 kDa, and the isoelectric points (pI) ranged from 4.62 to 10.44. A gene structure analysis showed that 43/51 (84.3%) CoDREBs were intronless, and the number of exons varied from one to three. Then, we focused on the response of CoDREB genes in terms of plant drought and cold acclimation. Under short-/long-term drought stress, CoDREB1.2/4.1/4.4/4.8/4.12/4.15/5.1/5.3/5.5/6.2 have different regulations in response to long-term drought response, and CoDREB1.4/2.5/4.6/4.1/6.3/6.5 specifically in the short term. Additionally, in response to mild/severe drought and followed by recovery, we found that CoDREBs may be involved in a complex drought-responsive regulatory network. Under cold stress, CoDREB5.2 and CoDREB6.5 are significantly up-regulated, and CoDREB may participate in the regulation of the low-temperature response of C. oleifera. Full article

Ardisia crenata var. bicolor is a multi-purpose plant and has important ornamental and medicinal properties. Conventional methods of propagating the species from seeds and cuttings have low efficiency because of the recalcitrant properties of seeds and low survival rate of high-quality cuttings. This work aims to study the in vitro regeneration protocol for direct organogenesis from nodal segments of A. crenata var. bicolor on Murashige and Skoog (MS) medium, with different combinations and concentrations of plant growth regulators (PGRs). The treatments used for the establishment and proliferation of shoots included MS medium supplemented with different concentrations of Benzyl-aminopurine (BAP) and indole-3-butyric acid (IBA). For rooting, IBA was used in combination with naphthaleneacetic acid (NAA) in full- and half-strength MS media. Maximum shoot establishment (76.67%) and the highest shoot length (6.6 cm) were observed on MS medium with 1.0 mg·L⁻¹ BAP with 0.5 mg·L⁻¹ IBA, while BAP at 1.0 mg·L⁻¹ with 0.25 mg·L⁻¹ IBA obtained the highest shoot proliferation (4.5 ± 1.53). The best rooting response (83.33%) was achieved on half-strength MS including 1.0 mg·L⁻¹ IBA with 0.25 mg·L⁻¹ NAA, and the maximum survival rate of 84.4% was observed after acclimatization under 75% shading. To define their genetic stability, using eleven primers of ISSR markers to assess the genetic stability of the unstable leaf color samples compared with their mother plant, the ISSR markers demonstrated a level of genetic polymorphism in plantlets, but without other morphological variations. This indicates the genetic resemblance to the mother plant and the reliability of this protocol for the efficient micropropagation of A. crenata var. bicolor. Full article

Sugar beet (Beta vulgaris L.) is cultivated in temperate climates worldwide to produce sugar. The production of sugar beet and other plants is in danger due to the world’s increasingly salinized soils. Although different sugar beet genotypes exist at various ploidy levels, most of them are diploid (2X) with 18 chromosomes. The majority of polyploid plants have different variations, morphologies, and anatomy. Diploid and polyploid plants especially have different morphology, physiology, cellularity, and biochemistry. As a result, polyploidy has been identified as an essential component in determining plant salt tolerance. To evaluate the effects of salt (NaCl) stress on sugar beet genotypes, diploid (2X), triploid (3X), and tetraploid (4X) genotypes were exposed to 0 (control), 50, and 150 mM NaCl concentrations for seven weeks. Under control conditions, the diploid (2X) genotype showed higher growth performance compared to the tetraploid (4X) and triploid (3X) genotypes, respectively. Regarding germination and early-stage growth performance, a reduction of about 50% was observed in the diploid (2X) genotype under salt stress compared to the control condition. The diploid (2X) genotype showed higher germination, a greater salt tolerance index, and better seedling growth performance than the other ploidy levels. Late-stage growth, leaf length, leaf width, leaf area, cytological findings, and total chlorophyll content were all shown to be higher and less reduced (around 30%) under salt stress in diploid (2X) genotypes. Even though all of the findings in this study showed a decrease when plants were exposed to salt (NaCl), the diploid (2X) ploidy level plants displayed more robust growth and development than the triploid (3X) and tetraploid (4X) genotypes. Full article

Understanding the critical stages in ovule development is essential for optimizing in vitro seed propagation, cryopreservation, and indirect somatic plant embryogenesis. We studied the main stages of the megasporogenesis and megagametogenesis of Coelogyne speciosa subsp. fimbriata (J.J.Sm.) Gravendeel by confocal laser scanning microscopy. The ovule is anatropic, tenuinucellate, bitegmal, and funicular. The embryo sac is monosporic, Polygonum-type, bipolar, and usually 8-nuclear, but in cases of a reduction in the last mitotic division, it is 6-nuclear. Endosperm formation was not detected. The formation of a functional megaspore occurred 65–70 days after pollination (DAP), while the formation of a mature embryo sac and fertilization occurred after 85–100 DAP. Full article

Worldwide, virus infections in grapevines are of concern due to the potential for economic loss. Although the grape industry in Mexico is relatively small and focused mainly on the local market, production dates back to the time of the Spanish colonization. This manuscript discusses the findings on grapevine viruses in Mexico. Nine viruses have been identified in the last fifty years, including grapevine red blotch virus (GRBV), grapevine leafroll-associated virus 3 (GLRaV-3), grapevine fanleaf virus (GFLV), and grapevine virus A (GVA). Important information is provided about these viruses and viral pathogens that have not yet been reported in Mexico, but represent an ongoing threat to plant health and grapevine production in other viticultural regions of the world. Strategies for virus control in vineyards are described. The information discussed here should be shared with growers and stakeholders to prevent future negative impacts on the Mexican grapevine industry and to save ancient grapevine accessions. Full article

Water deficit conditions trigger the production of a chemical signal, the phytohormone abscisic acid (ABA), which coordinates multiple responses at different temporal and spatial scales. Despite the complexity of natural drought conditions, the modulation of ABA signaling could be harnessed to ameliorate the drought performances of crops in the face of increasingly challenging climate conditions. Based on recent studies, increasing ABA sensitivity can lead to genotypes with improved drought resistance traits, with sustained biomass production in water-limiting environments and little or no costs with respect to biomass production under optimal conditions. However, variations in ABA production and sensitivity lead to changes in various aspects of reproductive development, including flowering time. Here we provide an updated summary of the literature on ABA-related genes in tomato and discuss how their manipulation can impact water-deficit-related responses and/or other developmental traits. We suggest that a better understanding of specific ABA components’ function or their expression may offer novel tools to specifically engineer drought resistance without affecting developmental traits. Full article

Sorghum is the agricultural crop most adaptable to the effects of abiotic factors, able to tolerate prolonged soil and air droughts, changes in air temperature, insufficient precipitation, salinization, acidification of soils, and many others with the least loss of yield compared to traditional crops such as wheat and barley. However, even among sorghum genotypes, there are samples with varying degrees of resistance to stressors, for example, drought. The aim of this study is a comprehensive study of the influence of abiotic factors on the physiological characteristics and biochemical parameters of sorghum grain. The experiment was carried out on the experimental field and laboratory conditions of the Rossorgo Institute. Drought resistance of plants is determined in the initial phase of development and during the flowering period by the degree of seed swelling in hypertonic solutions and the water regime of the leaves (total water content, water deficiency, moisture loss, and water-holding capacity). The quality of the grain is determined using the spectrophotometry method for the main biochemical components, and likewise, the separation of the protein into fractions. The growing conditions of plants in 2021–2022 differ significantly in terms of hydrothermal indicators. As a result of the conducted research for use in breeding programs for the creation of new varieties and hybrids with increased stress resistance selected samples L-65/14, Magistr has high drought resistance in the degree of seed swelling in hypertonic solutions (55.2–58.9%), which turned out to be at the level of the control variant (61.6–63.7%), and indicators of the water regime of the leaves (total water content of leaf tissues—74.20–77.83%; water-retaining capacity—83.77–85.56%; low moisture loss for 1 h/day—2.86–3.01%). These samples were characterized by the biological value determined by the optimal ratio of major indicators of grain and protein fractions: albumin (16.59–22.75%), globulin (8.13–9.09%), glutelin (9.09–14.01%), and prolamin (5.79–11.50%). Full article

Iran, possessing unique topographic and diverse climatic conditions, is the home of 8167 vascular plant species. Iran has a historical tradition in using plants for medicinal purposes. Approximately 2075 species over the whole are popularly characterized as medicinal or aromatic. Medicinal trees and shrubs compose a significant percentage of Iranian medicinal flora. Nonetheless, there are no integrated databases on their applications and most of the publications and documents have been scattered to date. Therefore, the present investigation aims to integrate the published literature considering its ethnobotanical aspects that would serve as promising precursors for developing potent medicines of plant origin. In the study, we compile information about ethnobotany of trees and shrubs of Iran. Our survey found 174 taxa belonging to 109 genera and 56 families. The majority of species were classified in Rosaceae, Fabaceae, Rutaceae, Salicaceae, and Lamiaceae families. Rosaceae was the most dominant, representing 21.8% of the total plant species recorded, among them, the genus with the highest number of species was Prunus (16 species). Berberis vulgaris, Citrus limon, and Betula pendula have the highest number of medicinal uses (24 number of uses) in Iran. Leaves (22.7%) represented the most dominant usage of the plant parts, while the most commonly used preparation method was infusion (33.5%). Most of the plant species have been consumed for digestive system treatment (21%), followed by immune system treatment (20%). The present review highlights that different trees and shrubs taxa have great traditional applications in various healing throughout the Iranian territory. The represented data can potentially be a precious reference containing useful information for directing further phytochemical, biological, and pharmacological investigations. Several endemic species of trees and shrubs, particularly Ribes khorasanicum, are frequently used in Iranian traditional medicine. Because of overharvesting, these species are calling a wake-up alarm for conservation. Full article

Understanding the mechanisms of plant salt tolerance as a complex trait is an integral part of many studies, the results of which have been used in the breeding process. The aim of this study was to compare the root response of two tomato (Solanum lycopersicum L.) genotypes (breeding line YaLF and cultivar Recordsmen) differing in salt tolerance. Rhizogenesis was induced in tomato shoots in vitro with different concentrations of NaCl in the culture medium. A number of morphobiological and cytological parameters were evaluated at the organ, tissue, and cellular levels for possible use in a comprehensive assessment of genotypes for salt tolerance. The influence of NaCl caused disruption of the cell cycle and redistribution of cells in the phases of the cell cycle. An increase in the degree of vacuolization was shown in cv Recordsmen at 75 and 150 mM NaCl and in the YaLF line at 150 mM NaCl. Under salt action, an increase/decrease in the length of cells such as columella cells (both genotypes) and epidermal cells (in cv Recordsmen at 75 and 150 mM NaCl) was shown. Differences between genotypes were demonstrated by changes in the area of the central cylinder and primary root cortex cells, as well as by changes of the S_nucleolus/S_nucleus ratio in these cells. Transmission electron microscopy (TEM) showed the modification of the chromatin structure in the root cells of these genotypes. Various cytoskeletal disorders were revealed in interphase cells of the tomato root of cv Recordsmen and the YaLF line by immunofluorescent staining under saline conditions. These morphometric and cytological parameters can be used for a comparative evaluation of genotypes differing in salt tolerance in a comprehensive assessment of varieties. Full article

Nitrogen availability is one of the critical determinants of agricultural yield. Biological nitrogen fixation, such as legume–rhizobia symbiotic association, might function as a solution to fix nitrogen. Using phytosulfokine (PSK)-α sequences as a query, Yu et al., 2022 performed a comprehensive genome-wide search of legume species to identify PSK-δ, a divergent pentapeptide differing in single amino acid. Furthermore, PSK-δ exhibited nodule-specific expression with lower expression in the root, substantiating the nodule-specific temporal expression and suggesting its role in nodule development and nitrogen fixation. Additionally, in planta functional characterization in Medicago truncatula using overexpression and Tnt1-insertion mutant analysis indicated the role of PSK-δ in symbiotic nodulation. Interestingly, a similar phenotype of MtPSKδ mutant (mtpskδ) with that of wild-type control led to the hypothesis of its functional redundancy with PSK-α in nodule organogenesis. Further investigation regarding its position in the Nod-factor signaling pathway revealed the downstream function of PSK-δ in association with MtENOD11 in regulating nodule formation. Full article