Laticifers are specialized structures found in diverse plant families and are regarded as important components of plant defense systems. In Fabaceae, however, laticifers are relatively uncommon and have been reported in only a few genera, including Mimosa. Despite this, little is known about the ultrastructural features of laticifer protoplasts and cell walls in this group, as well as their distribution throughout the plant body. This study investigated the distribution, anatomy, and ultrastructure of laticifers in Mimosa caesalpiniifolia Benth. (Fabaceae: Caesalpinioideae) from a developmental perspective, encompassing the embryo, seedling, and adult stages. Articulated nonanastomosing laticifers were found associated with both primary and secondary phloem. Total lipids, acidic polysaccharides, and terpenes were detected within the laticifer protoplasts. Primordial laticifer cells displayed thick pectocellulosic walls containing plasmodesmata, dense cytoplasm and abundant organelles. Young laticifers exhibited digitiform extensions toward neighboring cells, while in maturing laticifers, the terminal walls of aligned cells underwent dissolution. Mature laticifers showed an additional discontinuous internal parietal layer of uniform appearance, composed of callose. To the best of our knowledge, this study provides the first report of callose in laticifers of a legume species. The potential protective role of callose as a self-cytotoxic barrier and as a defense mechanism against natural enemies in the laticifer system is hypothesized. This study fills an important gap in the knowledge of laticifer origin and typology in Fabaceae and provides valuable insights to support taxonomic, ecological, and sustainable-use studies of this multipurpose forest species native to the Brazilian semi-arid region. Main Conclusion. Articulated, nonanastomosing laticifers are present throughout the development of Mimosa caesalpiniifolia, occurring in mature embryos,seedlings, and adult plants. A discontinuous parietal layer composed of callose internally lines the laticifer cells.

This study examined the influence of exogenous gamma-aminobutyric acid (GABA) on drought tolerance in faba bean (Vicia faba) under 15% PEG-induced drought stress conditions. Faba bean plants were subjected to treatments with varying GABA concentrations (0.5, 1, and 2mM) to evaluate physiological, biochemical, and molecular responses to drought stress. The results indicated that a concentration of 0.5mM GABA significantly enhanced the photosynthetic rate, stomatal conductance, and chlorophyll content, while also markedly improving relative water content (RWC). At this concentration, GABA treatment mitigated oxidative damage, evidenced by reduced levels of malondialdehyde (MDA) and hydrogen peroxide (H₂O₂), and increased antioxidant enzyme activities (catalase, superoxide dismutase, and ascorbate peroxidase). Furthermore, GABA supplementation influenced the accumulation of proline and soluble sugars, thereby facilitating osmotic regulation and stress adaptation. Gene expression analysis revealed that GABA modulated key drought-responsive genes, notably enhancing the expression of those associated with antioxidant defenses (VfCAT, VfSOD, VfAPX), water transport (VfPIP), and osmoprotection (VfP5CDH), particularly in leaf and root tissues, with differential effects observed across GABA concentrations. Interestingly, higher concentrations of GABA (1 and 2mM) yielded reduced or inconsistent outcomes, suggesting the existence of an optimal concentration threshold for stress mitigation. Collectively, these findings underscore the potential of GABA as a beneficial agent for enhancing drought resilience in faba bean, providing a promising strategy to improve crop tolerance to water scarcity.

Drought stress severely impacts mung bean [Vigna radiata (L.) R. Wilczek] production, making exploration of drought tolerance and breeding strategies critical. This study investigated drought resistance mechanisms in ten mung bean cultivars under polyethylene glycol (PEG 6000)-induced water deficit, analyzing germination, morphology, and physiology. Drought impaired vigor index (VI) and seedling growth across all cultivars, with mung bean Bing 20 exhibiting reduced VI (76.28%) and seedling length (63.47%). Drought induced hydrogen peroxide (H2O2) bursts, exacerbating membrane lipid peroxidation and elevating malondialdehyde levels, wherein increased H2O2 content in Bing 18 (2.02-fold) and elevated malondialdehyde content in Bing 17 (36.64%). Mung bean activated superoxide dismutase, peroxidase, and catalase antioxidant enzymes to mitigate oxidative damage and enhanced seed vigor by upregulating amylase and osmolyte accumulation (soluble sugar, starch, soluble protein, and proline); α-amylase activity in Jin 8 was elevated by 1.68-fold, while Jin 1 exhibited increased starch (1.57-fold) and proline content (40.28-fold). Based on drought resistance coefficients derived from these traits, correlation and principal component analyses (PCA) were performed. Mung bean Jin 1, Jin 7, Jin 8, Bing 11, and Bing 18 were identified as relatively tolerant, whereas Bing 16, Bing 17, Bing 19, Bing 20, and Bing 21 exhibited greater susceptibility. Correlation analysis revealed contrasting metabolic strategies tolerant varieties prioritized rapid early growth, while susceptible varieties showed a complex balance of growth, defense, and osmotic adjustment. PCA identified germination index and seedling length as key drought resistance screening traits. These findings enhance understanding of drought tolerance and facilitate selection of varieties. HIGHLIGHTS: Drought tolerance of ten mung bean cultivars was comprehensively evaluated based on germination, morphological, and physiological profiles under PEG-induced stress. Distinct drought response strategies were revealed between tolerant (prioritizing rapid early growth) and susceptible (balancing growth, defense, and osmotic adjustment) mung bean varieties. Germination index and seedling length were identified as key indicators for screening drought-tolerant mung bean varieties.

Viruses transmitted by the obligate biotrophic parasite Polymyxa graminis cause substantial losses in agriculture worldwide. A better knowledge of the infection process may lead to the identification of novel strategies for virus control. The coat protein readthrough (CP-RT) protein or its homologs, present in all P. graminis-transmitted viruses, are transmission factors of the viruses. To better characterize CP-RT function, we modified an infectious Japanese soil-borne wheat mosaic virus (JSBWMV) cDNA clone to express fluorescent protein-tagged CP-RT and analyzed the protein during infection in the model host plant Nicotiana benthamiana. We found that JSBWMV CP-RT localized to and self-interacted at the endoplasmic reticulum (ER) network and in small cortical particles during infection. The particles moved along the ER network and associated with sub-ER sites, most likely ER import sites, as indicated by co-localization with Sar1-GTP:GFP and AtSYP72:GFP. Particles were still present after reabsorption of the Golgi into the ER network after Brefeldin A treatment, thus they were not an intrinsic part of the Golgi-ER compartment. In natural CP-RT deletion mutants, the localization to the ER network was lost, while localization to the particles was maintained. Consistent with earlier data our findings from transmission experiments in hydroponic barley culture indicate that an intact JSBWMV CP-RT may be important for virus transmission by the vector, as more wild type CP-RT forms compared to mutant CP-RT forms accumulated in newly infected plants. ER-association of CP-RT may thus be important for virus transmission and early infection processes.

The microbiota associated with Cannabis sativa L. plays a crucial role in plant growth and health, although the mechanisms by which it is modulated in response to different types of stress during cultivation remains under investigation. In this study, the bacterial microbiota of both rhizospheric and bulk soil associated with a therapeutic C. sativa variety was characterized across three stages of the cultivation cycle (early vegetative, late vegetative, and late flowering), comparing healthy plants and those under stress induced by Tetranychus urticae. In addition to microbial profiling, plant physiological parameters were assessed, along with the analysis of cannabinoid and terpene profiles in floral tissues. Analyses of alpha diversity, community structure, discriminant taxa (LEfSe), and functional predictions (PICRUSt2) were performed using 16S rRNA gene sequencing data. The results revealed stress-associated shifts in the rhizospheric bacterial community, characterized by changes in the dominance of several genera across plant developmental stages, including a reduced representation of taxa commonly associated with plant growth promotion. Functional predictions further indicated that in control conditions the rhizosphere community exhibited higher metabolic activity, enriched in pathways related to replication, transcription and protein synthesis, whereas under stress, functions shifted toward resource recycling and metabolic flexibility. These findings suggest that biotic stress triggers a functional and structural reorganization of the soil bacterial microbiota, favoring more resilient yet less beneficial communities for plant development.This study provides novel evidence of the interaction between insect, plant, and microbiota, with both agronomic and biotechnological implications.

Biotic and/or abiotic stressors dampen crop productivity and affect sustainability worldwide. To address these challenges, it is crucial to associate the desired stress-responsive genes with specific stress-inducible promoters for developing plant varieties with broad-spectrum stress tolerance. In this study, the promoter region of the anthocyanidin synthase (ANS) gene from banana was thoroughly analysed, and its tissue-specific expression, in response to various environmental insults was delineated. Comprehensive analyses such as transcript abundance-based expression profiling and evaluation of ProANS-GUS activity in transgenic lines was performed and the expression patterns thus obtained were corroborated with the presence of corresponding cis-elements in the promoter region. Transcription of the ANS gene was strongly altered by the imposition of environmental stresses or signaling molecules. MusaANS transcripts in banana were significantly suppressed by exposure to high salinity, salicylic acid or abscisic acid, while its expression was stimulated by methyl jasmonate as well as drought. In PMusaANS-GUS transformed tobacco lines, PMusaANS activity was mainly observed in the vascular tissue under control conditions. Drought, salinity, MeJA, salicylic acid and ABA strongly activated PMusaANS whereas, ethephon suppressed its activity. Thorough scrutiny of PMusaANS showed the presence of a diverse array of stress and phytochemical response-associated cis-elements, such as ARR1AT (cytokinin), ACGTATERD1 (drought), DPBFCOREDCDC3 (ABA), ABREOSRAB21 (ABA), ASF1MOTIFCAMV (salicylic acid), ERELEE4 (ethylene) and BIHD1OS (pathogen response). Based on the results, PMusaANS is differentially activated under stress and hence is an excellent stress-inducible candidate promoter for producing resilient transgenic crop varieties.