Int. J. Plant Biol., Volume 14, Issue 4 (December 2023) – 24 articles

Early rice disease detection is vital in preventing damage to agricultural product output and quantity in the agricultural field. Manual observations of rice diseases are tedious, costly, and time-consuming, especially when classifying disease patterns and color while dealing with non-native diseases. Hence, image processing and Machine Learning (ML) techniques are used to detect rice disease early and within a relatively brief time period. This article aims to demonstrate the performance of different ML algorithms in rice disease detection through image processing. We critically examined different techniques, and the outcomes of previous research have been reviewed to compare the performance of rice disease classifications. Performance has been evaluated based on the criteria of feature extraction, clustering, segmentation, noise reduction, and level of accuracy of disease detection techniques. This paper also showcases various algorithms for different datasets in terms of training methods, image preprocessing with clustering and filtering criteria, and testing with reliable outcomes. Through this review, we provide valuable insights into the current state of ML-based approaches for the early detection of rice diseases, and assist future research and improvement. In addition, we discuss several challenges that must be overcome in order to achieve effective identification of rice diseases. Full article

In vitro regeneration of passion fruit has great prospects for mass production of disease-free planting materials. The objective of this study was to develop an in vitro regeneration system through somatic embryogenesis for farmer-preferred genotypes grown in Kenya. Callus induction and somatic embryogenesis were carried out using leaf and immature seed explants. The explants were cultured on Murashige and Skoog medium augmented with different concentrations of 2,4-dichlorophenoxyacetic acid (2,4-D) alone and 2,4-D combined with 1.0 mg L⁻¹ thidiazuron (TDZ). Data were recorded and subjected to analysis of variance. The highest number of somatic embryos was obtained from KPF4 genotype using MS medium supplemented with 8 mg L⁻¹ 2,4-D and 1 mg L⁻¹ TDZ^. The embryos were converted to plants on germination medium comprising of MS augmented with 0.5 mg L⁻¹ 6-benzyl amino purine (BAP). The plantlets were hardened for 4 weeks in plastic pots. The survival rate during hardening of in vitro regenerated plants was 77.8%. The present study reports a regeneration system through somatic embryogenesis for KPF4 passion fruit grown in Kenya. The in vitro regeneration system can be utilized for mass propagation and genetic improvement of KPF4 variety grown in Kenya. Full article

Agriculture in the Andean region is mainly small-scale and rainfed, especially in Peru where almost 80% of its population depends on agriculture-related activities. Climate change in addition to social factors threatens the food security of this region. The forecast of more frequent dry spells would especially affect potato crops, domesticated centuries ago in the Andes, where there remains a great genetic diversity. This study aimed to characterize the response to drought stress of 79 potato landraces traditionally grown in the Central Andes of Peru (Pasco region) as a first selection for future breeding evaluations. The used indices were mean productivity (MP), geometric mean productivity (GMP), stress tolerance (STI), stress susceptibility (SSI), and tolerance index (TOL), and a scoring methodology that integrates all of them into a single descriptor in a simple and fast way. The varied responses showed a wide genetic diversity within the assessed landraces, where at least nine of them own high resilience and productivity qualities, and many others are highly vulnerable to drought. It is recommended to complement these studies with physiological and molecular evaluations in stress situations, especially in those with tolerance qualities highlighted in this study, and thus promote the conservation of the biodiversity of this region. Full article

Bacterial leaf blight (Xanthomonas oryzae pv. oryzae) is a significant rice disease. Aqueous crude extracts of Kalanchoe pinnata were shown to induce rice resistance against the disease. This study aims at testing the disease-reducing effects of K. pinnata leaf extracts using the liquid–liquid extraction method with three different solvents (dichloromethane, methanol, and water). This serves as a basis to select appropriate extracts for effective disease control. Three concentrations (1, 1.5, and 2%) of each extract were tested using seed soaking. The extracts did not show adverse effects on seed germination and seedling growth. Methanol extracts showed significantly different effects compared to those of the untreated control. The involvement of induced resistance in the disease reduction was shown through activities of the four defense-related and antioxidant enzymes, i.e., peroxidase (POX), catalase (CAT), polyphenol oxidase (PPO), and phenylalanine ammonia lyase (PAL). Using 1% methanol extract, activities of POX and CAT involved in hydrogen peroxide production in rice tissues increased 1–4 days after pathogen inoculation (DAI) and remained at high levels until 6 DAI. Activities of PPO and PAL involved in resistance signaling pathways significantly increased after pathogen inoculation. Activities of the four enzymes generally increased after pathogen inoculation and reached higher levels with extract applications. Full article

The question of the effect of the anion type on halophyte salt tolerance and ion accumulation is still far from the necessary generalization due to the lack of comparative studies. The aim of the present study was to compare the relatively long-term effect of treatment with various salts formed by different anions on the growth and ion accumulation of several halophyte species in controlled conditions. The main experiments with the largest variety of individual salt types were performed with Cochlearia officinalis L. and two cultivars of Limonium sinuatum (L.) Mill. In addition, experiments with Lobularia maritima (L.) Desv., Plantago maritima L., and Tripolium pannonicum (Jacq.) Dobrocz. focused on the comparison of neutral (NaCl) and alkaline (NaHCO₃) salts as well as NaNO₃. Acetate salts appeared to be the most toxic, with only Plantago and Tripolium plants being able to withstand full treatment while having a pronounced inhibition in growth. Only the two Limonium cultivars were more susceptible to treatment with alkaline salts in comparison to that with neutral salts. In treatments with alkaline salts, the ion accumulation potential was lower in comparison to plants treated with chlorides and nitrates. It can be concluded that the type of anion is a significant determinant of salinity tolerance and ion accumulation in halophytes, but a high genotype dependence of the responses makes it difficult to generalize the obtained results. Full article

Rose flowers have been cultivated for their fragrance and their garden value since ancient times. Very ancient cultivars became famous locally for their specific use, and competitive horticultural activities progressively established, leading, with time, to landraces with limited polymorphism. The most famous examples are the oil-bearing Damask roses from Iran and the Yueyue Fen garden strain from China. In 1817, a new rose, allegedly a hybrid from the two previous lineages, was discovered at Reunion. From this plant, as early as the 1820s, a new founder group, the Bourbon roses, was developed in France, which immediately stirred up deep passions among botanists and skilled enthusiasts. Today, more than 30,000 named cultivars have been raised either as garden and landscape plants for the cut rose market or as indoor pot plants. The market handles billions of euros a year, making the rose the most economically important crop worldwide. Following the inheritance of SSR DNA markers, we here propose a reconstitution of the very early lineage of Bourbon roses, clarifying one of the major steps, if not the major one, that links these very ancient heritage roses to modern roses. Full article

Farmers hoping to manage cropping systems sustainably are turning to cover crops to help mitigate plant pathogens. Plants with biofumigant properties are used to control soil-borne pathogens in agricultural settings, especially in till systems, where the brassicas are incorporated into the soil as green manure or seed meal. The effect of these crops is not well studied in no-till systems; thus, it is hard to know if they are as effective as green manure. Whether or not these cover crops can effect changes during a single growth season has not yet been studied. This study compared the response of the soil microbial community to four different brassica cover crops, two of which are commonly used in vineyards (Sinapis alba L. (white mustard) and Raphanus sativus (L.) Domin (tillage radish)) as well as two brassicas that are native or naturalized to the Okanagan (Capsella bursa-pastoris (L.) Medik. (Shepherd’s purse) and Boechera holboelli (Hornem.) Á. Löve and D. Löve (Holbøll’s rockcress)). Cover crops did not affect fungal species richness, but B. holboelli recover crops were associated with increased evenness among fungal taxa. Both C. bursa-pastoris and S. alba had lower levels of plant parasitic nematodes compared to non-brassica controls. These results were apparent only after a single growing season, which indicates growers could use this approach as needed, minimizing long-term exposure to biofumigants for beneficial soil microbes. Full article

Barley stripe mosaic virus (BSMV)-based vectors are frequently used in virus-induced gene silencing (VIGS) and, more recently, viral overexpression (VOX) studies in wheat. Two general strategies are employed to initiate infection in wheat plants with BSMV in VIGS and VOX studies. One method involves the direct infection of wheat using viral RNA produced via the in vitro transcription of BSMV constructs. The second class utilizes viral replication in an intermediate host plant to produce large amounts of BSMV viral particles that are then used to inoculate wheat plants. This study was designed to examine the potential for BSMV-VIGS constructs to rearrange during replication in the intermediate host and result in initiating the VIGS studies with a virus that is significantly different from the original experimental construct. It is shown that in the case of BSMV-VIGS constructs harboring a PDS-silencing fragment, significant rearrangement can occur during replication in the intermediate host that has the potential to introduce artifactual experimental outcomes. Full article

Ensuring the quality attributes of cashew kernels is essential for selecting superior genotypes with agro-industrial potential. Therefore, this study characterized cashew nut accessions from the Cashew Germplasm Bank regarding kernel quality standards and identified genotypes with optimal characteristics for the industry. The characterization included key industrial indicators such as peeling efficiency, average kernel mass, class, type, and industrial yield, evaluated in 47 different accessions. Through multivariate cluster analysis and principal component analysis, the accessions revealed four distinct groups, exposing correlations among various industrial indicators. The analysis revealed a diverse genetic profile within the Cashew Germplasm Bank. A notable finding is that 80.85% of the accessions group together, displaying predominant features—easy peeling, an average mass exceeding 2.5 g, categorized as super large (SLW) and large (LW), and uniformly white-colored kernels. Correlations found include a negative relationship between kernel mass and class and positive associations between class and industrial yield, as well as between industrial yield and peeling efficiency. The study reveals substantial variability in cashew nut germplasm with respect to quality traits, highlighting its invaluable potential for identifying and selecting superior genotypes adapted for agro-industrial purposes. Particularly promising are Group 4 accessions, such as BGC632, BGC589 and BGC127, presenting attributes indicative of high-quality kernels. Full article

Estimation of carbon (C) stocks revealed a very high carbon sequestration potential of mangroves, which play a major role in the global C cycle. The C stored in the biomass of live trees can be estimated from above- and below-ground measurements, i.e., tree diameter and height, leaf litter, root biomass, necromass, and soil. The allocation of biomass and C in the scrub mangrove forest is influenced by various factors, including low structural development. The objective of this study was to estimate the carbon stock (in relation to biomass) and storage in the soil of the San Ignacio and El Dátil lagoons in an arid region of the north Pacific. Above-ground biomass (AGB) was estimated based on mangrove structure and leaf litter; below-ground biomass (BGB) was measured by extracting root cores (45 cm depth) and soil (1.2 m depth). Biomass values were converted to carbon with allometric equations. We found an inverse relationship between BGB content (roots) and above-ground structural development, with a mean total biomass (AGB + BGB) of 101.7 MgC ha⁻¹. Below-ground carbon content (roots, necromass, and soil) was 2.8 times higher than above-ground carbon content (trees and litter). Control sites (devoid of vegetation) adjacent to the mangrove have recorded low carbon stocks of 7.3 MgC ha⁻¹, which supports the recommendations for conserving and restoring degraded areas. The present study contributes valuable information on carbon related to mangrove biomass and stored in the soil of arid mangrove areas of northwestern Mexico. Full article

In plants, an increasing number of traits and new characteristics are being developed using gene editing. Simple traits represented by a single gene can be managed through backcross breeding, but this is typically not the case for more complex traits which may result from the function of a large number of genes. Here, we demonstrate two case studies of improving oleic oil content and developing pod shatter reduction in Brassica napus by using gene editing tools on an industrial scale. There are four BnaFAD2 genes involved in oleic oil content and eight BnaSHP genes involved in pod shatter tolerance. In order to develop these two traits, we delivered nuclease ribonucleoproteins with Gene Repair OligoNucleotides (GRONs) into protoplasts, with subsequent regeneration into plants on an industrial scale, which encompassed robust tissue culture protocols, efficient gene editing, robotics sampling, and molecular screening, vigorous plant regeneration, growth, and phenotyping. We can produce precise loss-of-function-edited plants with two improved agronomically important complex traits, high oleic oil or pod shatter reduction, in elite canola varieties within 1–3 years, depending on the trait complexity. In the edited plants carrying loss of function of four BnaFAD2 genes, the seed fatty acid oleic acid content reached 89% compared to 61% in the non-edited wildtype control. The plants carrying eight edited BnaSHP genes achieved 51% pod shatter reduction in multiple year field testing in the target environment compared to the wildtype control. Full article

Rose is a commercially significant floricultural crop that has been used for various industrial as well as decoration purposes. Along with the beautification of rose flowers, their leaves are enriched with different biologically active compounds having various therapeutic uses. The current study was performed on the phytochemical and antioxidant activity of aqueous extracts of rose leaves. In our study, we found there are consequential variations observed in all the parameters, viz., total chlorophyll, carotenoids, total anthocyanin, total phenol, flavonoids, and antioxidant activity, among all the varieties. Among the ten varieties, Thelma Barlow revealed the maximum phenolic content (35.19 mg/g FW), flavonoids content (15.97 mg/g FW), 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity of IC₅₀ value (206.86 ± 0.49 µg/mL), and 2,2′-azinobis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) (301.62 ± 2.31 µg/mL). The variety Grand Amore presented the highest values for total chlorophyll (1.41 mg/g FW) and carotenoids (36.29 mg/g FW) content compared to other varieties. Also, a comparative correlation was studied amongst the phytochemicals such as anthocyanin content, total phenolic content, flavonoids, and antioxidant activities. Amongst the different rose varieties, Grand Amore and Thelma Barlow contain higher antioxidant potential, owing to their greater phytochemical activity. From our findings, we collectively concluded that fresh rose leaves contain potentially higher phenolic and flavonoid content, i.e., are responsible for higher antioxidant activity, which can be utilized for various pharmacological as well as food industries. Full article

The endomembrane system in plant cells enables the cell to manage and coordinate a variety of membranous compartments so that they and their contents arrive at the right location. The secretory pathway is an essential part of this complex network and has its gateway at the Endoplasmic Reticulum. Therefore, alterations at the ER can affect how protein trafficking takes place and how cargo leaves this organelle. With this work, we assessed how abnormalities at the Endoplasmic Reticulum would interfere with protein sorting and trafficking. We used an Arabidopsis mutant—leb-2 GFP-h, presenting abnormal ER morphology, and evaluated the expression of aspartic proteinases and genes related to vacuolar transport along with the localization of a specific vacuolar sorting signal—plant-specific insert (PSI). Our results show that alterations in the leb-2 GFP-h mutant did not disrupt the transport of PSI–mCherry to the vacuole but influenced the expression of endogenous aspartic proteinases. Furthermore, the study of key endomembrane genes expression revealed an upregulation of the SNARE proteins AtVAMP722 and AtVAMP723. The leb-2 mutant seems not to interfere with vacuolar routes but may be implicated in secretion events. Full article

The excessive use of synthetic chemicals in agriculture demands sustainable alternatives to combat crop-affecting microorganisms. Plant-derived secondary metabolites have garnered attention as promising candidates with antimicrobial properties. This study investigates the antimicrobial potential of tobacco plants, specifically non-commercial accessions Nic 1015 (“TI 1341”) and BHmN, recognized for their rich bioactive compounds. Our objectives encompassed the extraction of leaf surface compounds and the assessment of their in vitro antimicrobial activity against crop-damaging microorganisms. Ethanol-based extracts, abundant in diterpenes, were meticulously analyzed. Notably, BHmN contained cis-abienol, while both accessions featured α-CBT diol, as confirmed by thin-layer chromatography (TLC) and high-performance liquid chromatography (HPLC). TLC-Bioautography and microdilution assays unveiled substantial antifungal activity. The growth inhibition percentages correlated with extract concentrations, highlighting the pivotal role of diterpenes. These extracts exhibited pronounced efficacy against Rhizoctonia solani and Stemphylium solani but displayed relatively weaker activity against Sarocladium oryzae. Notably, Nic 1015 extract demonstrated remarkable antifungal activity at a minimal concentration of 78 µg·mL⁻¹, while cis-abienol and sclareol inhibited the growth of Fusarium graminearum and Alternaria alternata. Additionally, the extracts demonstrated in vitro antibacterial activity against common plant culture contaminants, Bacillus licheniformis and Stenotrophomonas maltophilia. In conclusion, the findings underscore the potential of these extracts as effective tools for controlling pathogenic fungi and bacterial contaminants in plant in vitro cultures. Harnessing plant-derived secondary metabolites, especially those from tobacco leaf surface, presents a sustainable and eco-friendly strategy to mitigate the detrimental impact of microorganisms on agricultural crops, promising a greener alternative to synthetic chemical products. Full article

Physalis species are used as an indigenous food and medicine in Kenya. However, species identification and an analysis of the health-promoting bioactive compounds and antioxidant properties are lacking. In this study, we report the molecular identification and mineral and phytochemical profiling of wild Physalis accessions. Leaf samples of 10 Physalis accessions were collected and used for species identification using nuclear ITS2 and plastid rbcL barcodes. Ripe fruits were collected from the same accessions and analyzed for mineral, total phenolic, tannin, and flavonoid contents, and antioxidant activities. The Physalis species were discriminated based on the ITS2 barcode and identified as Physalis purpurea. The genetic diversity, distance, and polymorphism of the ITS2 region of Physalis accessions were high due to the high rate of singleton and parsimony mutations. No genetic diversity, distance, or polymorphism was observed based on the rbcL barcode. The mineral content was significantly different (p < 0.05) for calcium, zinc, nickel, copper, and lithium among the Physalis accessions. No significant variation (p > 0.05) was found for phenolic acids or flavonoids, but the tannic acid content varied significantly (p < 0.05). DPPH free radical scavenging varied significantly (p < 0.05) among Physalis accessions. In conclusion, nuclear ITS2 was used to successfully identify the Physalis species of all the accessions as Physalis purpurea. The present study confirmed that Physalis purpurea has a significantly high mineral and phytochemical content and antioxidant activity. The findings from this study can be used to facilitate exploitation of Physalis purpurea in genetic breeding, their application in pharmaceutical, cosmetic, and nutritional value as well as conservation and sustainable use. Full article

Using agricultural gypsum promotes nutrient descent and generates a less aggressive environment for roots, favoring their development and better use of water and nutrients. However, studies on apple trees are scarce, and there is no official recommendation for gypsum application in the soils of southern Brazil. This work aimed to evaluate the potential use of agricultural gypsum to increase soil fertility and apple tree productivity. The research was carried out in the municipality of Ipê, RS, in an apple orchard cv. Condessa planted fifteen years ago and with acidity in the soil layer of 20–40 cm. The design of the experiment was consisted of randomized blocks, containing five treatments and four replications, with 80 m² each. The treatments consisted of five doses of agricultural gypsum, applied at the beginning of the productive cycle. The study evaluated soil chemical parameters at 0–20 cm and 20–40 cm, chlorophyll content, and crop productivity. The results showed an increase in the sulfur content up to the gypsum dose of 6.0 t∙ha⁻¹ and a reduction in the magnesium content in the soil at both evaluated depths. Agricultural gypsum application did not significantly influence the other chemical parameters evaluated. Chlorophyll content in apple leaves was reduced, and there was an increase in productivity with the increase in the dose of agricultural gypsum. Therefore, gypsum can potentially improve soil fertility and increase apple tree productivity. Full article

Copper (Cu) is an essential plant micronutrient. This report is the first to assess the effects of high copper sulfate (CuSO₄) levels on in vitro callus and shoot formation of cucumber. Four-day-old cotyledon explants from the inbred line Wisconsin 2843 and the commercial cultivars Marketer and Negrito were used. Murashige and Skoog (MS)-derived callus and shoot induction medium containing 0.5 mg L⁻¹ indole-3-acetic acid (IAA) and 2.5 mg L⁻¹ 6-benzylaminopurine (BAP) was supplemented with CuSO₄ (0.2–5 mg L⁻¹). The response on callus-derived shoots showed that the optimal concentration of CuSO₄ was 8- to 200-fold greater than in standard MS medium. Shoot frequency (SF) and shoot number (SN) were assessed, and Marketer > Negrito > Wisconsin 2843, where 1, 0.2 and 5 mg L⁻¹ CuSO₄ produced the highest results, respectively. SF and SN increased 6- and 10-fold in Wisconsin 2843 and twice in the other cultivars. All explants formed calluses, and in two of the three cultivars, callus extension was significantly affected by CuSO₄ application. SN showed a strong relationship with CuSO₄ levels and no association with callus extension. The results show that specific CuSO₄ concentrations higher than in standard MS medium increase adventitious cucumber shoot organogenesis. Full article

Camellia quephongensis Hakoda et Ninh is a yellow-flowered camellia that inhabits the Que Phong District, Nghe An Province, North-Central Vietnam, and its taxon includes approximately 50 species from South China and Vietnam. Researchers have primarily focused on the taxonomy and biochemistry of medicinal substances found in camellia flowers and on horticultural studies of their propagation. Consequently, habitat characteristics and adaptation mechanisms still need to be better understood. Thus, this study investigated the habitats of C. quephongensis in terms of landscape and stand composition, analyzed the morphological variabilities and age distribution patterns among different habitat types, and explored its adaptation mechanisms. The results revealed that this species preferentially inhabited forests on vulnerable slopes and stream banks, which were frequently disturbed by slope failure or flooding, while its multi-stemming traits were key factors in recovering from damage and persisting in such habitats. Relatively stable sites with fewer disturbances can be a source habitat, whereas frequently disturbed sites can be a sink habitat for the populations. Regular thinning of the shrub and herb layers in the plantation maintained a stand composition similar to that of natural stands; thus, succession control is recommended to conserve the naturally growing site of this species. The findings of this study will aid in the future conservation and restoration of growing areas. Full article

Pink staining in shiitake (Lentinula edodes (Berk.) Pegler) billets (Quercus griffithii Hook.f. and Thomson ex Miq.) causing the inhibition of shiitake mycelium and a reduction in shiitake production was observed throughout Bhutan in 2017–2018. Completion of Koch’s postulates confirmed the causal agent to be Scytalidium cuboideum, a first record of this disease in shiitake billets in Bhutan. In failed billets, it was observed that there was no growth of shiitake mycelium from the spawn. Trials suggest that S. cuboideum is responsible for the occurrences of poor colonisation by shiitake spawn—even when pink staining is not evident. Warm temperatures favour S. cuboideum, with shiitake able to sometimes overcome low rates of infection when incubated at low temperatures. Full article

Carnarvon is a key horticultural district in Western Australia which is located approximately 900 km north of Perth and is characterised by a semi-arid climate. In Carnarvon, capsicum (Capsicum annuum L.) is the second most important vegetable crop after tomato, with approximately 3700 tonnes of capsicum fruit produced annually with a farm gate value of AUD 13.5 million. High temperatures, excessive sunlight, low air humidity, and strong wind in spring and summer are major impediments to the achievement of high yield and quality of capsicum in this region. Capsicums are usually planted between March (early autumn) and May (late autumn), and the harvest is usually finished by October (spring) of the same year when grown under shade net houses. However, the internal microenvironment in the shade net houses is sub-optimal for the crop in the early and late growing season due to excessive temperatures and low humidity, resulting in a shorter harvest window and lower production. This study was conducted to examine the possibilities to extend the cropping season for capsicum varieties (i.e., Chevello and Chevi) grown under the retractable roof production system (RRPS) and explore an alternative protected cropping structure that is more affordable and suitable to grow vegetable crops under Carnarvon weather conditions. Overall, the results showed that capsicums planted in February (planting 1) performed better than specimens planted later on in the season: planting 1 performed better and yielded the highest marketable fruit yield (102.6 t ha⁻¹) compared to those planted in early April (planting 2, 72.5 t ha⁻¹) and late May (planting 3, 36.1 t ha⁻¹). The RRPS effectively mitigated the adverse weather conditions and provided a more optimised internal microenvironment for vigorous crop establishment in late summer and an extended harvest in late spring, leading to a higher marketable fruit yield per crop. The total soluble solids were cultivar-specific, with the Brix level of Chevello changing with planting time while those of Chevi remained constant. The study identifies the potential for an alternative protected cropping structure, i.e., the modified multi-span polytunnels. The technical feasibility and affordability of the alternative protected cropping structure is also discussed. Full article

Maize (Zea mays sp.) is one of the most important basic grains in our diets, and it requires high levels of nitrogen and phosphorus for optimum growth. However, phosphorous transitions in forms inaccessible to plants. The Lupinus genus, and more specifically, Lupinus albus, through its root clusters, or proteoid roots, has the ability to solubilize portions of phosphorous when it is found in a limited environment. The objective of the current study was to evaluate the effect of Lupinus montanus under phosphorous stress conditions intercropped with maize, utilizing sandy soils with calcium phosphate bands. Work was conducted in growth chambers using rhizotrons, which allowed the authors to observe the growth and root behavior of both species (Lupinus montanus and maize). The phosphorus analysis in the plant tissue indicated that its concentration in maize was slightly higher in intercropping conditions than in monoculture planting. From this, we concluded that Lupinus montanus is capable of solubilizing portions of phosphorus, making it available for other crops; likewise, we also observed that the proteoid structures did not develop, leaving the study open for other wild species. In conclusion, the use of Lupinus montanus will be as an alternative in favor of more sustainable agricultural methods since it improve soil fertility in phosphorus deficient soils. Full article

Alkaloids are a class of secondary metabolites that play multifaceted roles in plant physiology, including defense mechanisms and interactions with other organisms. The alkaloids from Piper retrofractum (Javanese long pepper) fruits offer potential alternatives to synthetic pesticides due to their natural origin and insecticide properties. However, information on particular alkaloid biosynthesis pathways is required to enhance individual alkaloid production via metabolic engineering. Here, we perform HPLC profiling to demonstrate that fruit ripening influences the alkaloid diversity in P. retrofractum. De novo transcriptomic profiling of young, green mature, and red ripened fruits revealed that the piperine biosynthesis pathway genes were highly upregulated in the mature fruits. However, an enhanced accumulation of methyl piperate and guineensine in the ripened fruit was observed, entailing ripening-related differential gene expression to synchronize the alkaloid biosyntheses. Gene expression clustering and functional enrichment analysis identified a large group of genes involved in diverse biosynthetic processes explicitly enriched in the ripened fruits. A cohort of genes encoding for “Alkaloid Biosynthesis”, remarkably upregulated in the ripening fruits, indicates they may function directly in alkaloid diversity during a later stage of fruit development. This study provides the basis for metabolic engineering to enhance alkaloid diversity and production. Full article

Background: In the search of a rapid and representative method for the approximate calculation of culture density and cell content of useful pigments, the study of absorption spectra of cultures of the dinoflagellate Amphidinium carterae, the haptophyte Isochrysis galbana, the chlorophyte Nephroselmis sp., and the filamentous cyanobacterium Anabaena sp. were selected as representative species of different taxa. Methods: The experimental cultures were established in small volumes by the discontinuous method under 20–21 °C, salinity of 30 or 40 ppt, and 2000 or 8000 lux illumination, and the absorbance spectra, density of the culture and concentration of the extracted pigments chlorophyll, total carotenoids, and phycocyanin were recorded during cultivation. Results: Algal density can be predicted sufficiently correctly because the regression equation of the correlation of the OD value of 750 nm from each absorption spectrum and the measured algal biomass was very strong. The same is true for the corresponding correlations between OD 750 nm and the detected pigments. Conclusions: Absorption spectra of microalgal cultures can be a simple, inexpensive, and non-invasive method for the growers to obtain the necessary information for predicting the right time to collect an ideal combination of maximum biomass and useful pigments, provided that the interpretation of the spectra is performed according to the method described herein. Full article

Climate change has prompted agri-food systems to explore new strategies for improving the production of crops in a sustainable manner. This includes green bean, the most important legume in the world for its nutritional value. The use of omeprazole (OMP) and melatonin (MEL) has been proposed as innovative strategy for crop improvement when they are applied as biostimulants. However, although their role in the growth of several species has been studied, the results in photosynthetic efficiency parameters are still scarce. Therefore, the objective of the present study was to evaluate the effect of foliar application of OMP and MEL on biomass, yield, SPAD values, leaf chlorophyll fluorescence (Fv/Fm), photochemical quenching (qP), non-photochemical quenching (NPQ), quantum yield of photosystem II (PhiPSII), and electron transport rate (ETR) in bean plants. Treatments were applied separately at doses of 1, 10, and 100 µM, plus a control without application. The results obtained indicate that OMP and MEL were able to increase biomass; yield; SPAD values; and qP, Fv/Fm, and PhiPSII coefficients. Finally, it is concluded that foliar application of OMP and MEL at a dose of 1 and 10 µM can increase photosynthetic efficiency and decrease photoinhibition, which is reflected in higher biomass accumulation and yield in green bean plants cv. Strike. Full article