Stress Tolerance In Plants Research Articles

Transcription Factor OsMYB2 Triggers Amino Acid Transporter OsANT1 expression to Regulate Rice Growth and Salt Tolerance.

Amino acid transporters play important roles in plant growth and stress tolerance; however, whether the abscisic acid signaling pathway regulates their transcription in rice (Oryza sativa) under salt stress remains unclear. In this study, we report that the transcription factor OsMYB2 (MYB transcription factor 2) of the abscisic acid signaling pathway mediates the expression of the gene encoding the amino acid transporter OsANT1 (aromatic and neutral amino acid transporter 1), which positively regulates growth and salt tolerance in rice. OsANT1 was mainly expressed in the leaf blade and panicle under normal conditions and transports leucine, phenylalanine, tyrosine and proline, positively regulating tillering and yield in rice. Nevertheless, salt stress induced the accumulation of abscisic acid and strongly increased the expression level of OsANT1 in the root, resulting in enhanced salt tolerance of rice seedlings, as evidenced by higher proline concentration and antioxidant-like enzyme activities and lower malondialdehyde and hydrogen peroxide concentrations. Moreover, we showed that OsMYB2 interacts with the promoter of OsANT1 and promotes its expression. Overexpression of OsMYB2 also improved tillering, yield, and salt tolerance in rice. In conclusion, our results suggest that the transcription factor OsMYB2 triggers OsANT1 expression and regulates growth and salt tolerance in rice, providing insights into the role of the abscisic acid signaling pathway in the regulatory mechanism of amino acid transporters in response to salt stress.

Choline supplementation reduces cadmium uptake and alleviates cadmium toxicity in Solanum lycopersicum seedlings

Sustainable plant production in soil polluted with heavy metals requires that novel strategies are developed for the benefit of humans and other living things. Cadmium (Cd) is a common heavy metal pollutant for plants, and there is limited information on the use of exogenous bio-regulators to reduce the accumulation and toxic effects of Cd pollution in plants. Choline is an endogenous quertarnary amine that is known to improve stress tolerance in plants, while its mechanism of action in certain conditions is yet to be determined. This study investigated the effects of foliar choline supplementation (10 mM) on Solanum lycopersicum seedlings exposed to Cd application (50 mg/L in soil). The seedlings were randomized to five groups: Control (E1), Cd stress (E2), Choline supplementation after Cd stress (E3), Choline (E4), and Choline supplementation before Cd stress (E5). Following the applications, the Cd content, growth and development parameters (chlorophyll content, fresh and dry weight), oxidative stress parameters (H2O2 and MDA contents), as well as antioxidative defense system (SOD, GSH, AsA, and TPC contents) were analyzed. Choline supplementation after Cd stress reduced the enhanced Cd content in roots by 38% but did not alter it in leaves (p > 0.05) compared to the Cd group. Choline supplementation before Cd stress decreased Cd content both in roots by 87.5% and in leaves by 50%. Choline supplementation after and before Cd stress increased fresh and dry weights in both roots and leaves. While the Cd group (E2) increased the H2O2 level and SOD activity, no remarkable change was observed in H2O2 levels in all choline supplementations (E3, E4, E5). Therefore, lipid peroxidation (MDA) was not observed in choline supplementation before Cd stress (E5), however, when the choline was applied after Cd stress (E3) MDA content was reduced by 40% compared with the Cd stress group (E2). Choline supplementations after and before Cd stress (E3, E5) increased AsA content by 30%, while the Cd group (E2) decreased it by 60% compared with the control group (E1). Choline supplementations before Cd stress (E5) increased TPC by 33%, while the Cd group (E2) decreased it by 18%, moreover, when choline was applied after Cd stress (E3), no change was observed compared to the control group. These data suggest that choline prevents inhibition of plant growth due to Cd toxicity by reducing Cd uptake. The results provided in the present study are likely to enhance the quality and efficiency of crop production in heavy metal-polluted areas.

Evaluating Native Bacillus Strains as Potential Biocontrol Agents against Tea Anthracnose Caused by Colletotrichum fructicola

Anthracnose of the tea plant (Camellia sinensis), caused by Colletotrichum spp., poses a significant threat to both the yield and quality of tea production. To address this challenge, researchers have looked to the application of endophytic bacteria as a natural alternative to the use chemical pesticides, offering potential for enhancing disease resistance and abiotic stress tolerance in tea plants. This study focused on identifying effective microbial agents to combat tea anthracnose caused by Colletotrichum fructicola. A total of 38 Bacillus-like strains were isolated from the tea rhizosphere, with 8 isolates showing substantial inhibitory effects against the mycelial growth of C. fructicola, achieving an average inhibition rate of 60.68%. Among these, strain T3 was particularly effective, with a 69.86% inhibition rate. Through morphological, physiological, and biochemical characterization, along with 16S rRNA gene phylogenetics analysis, these strains were identified as B. inaquosorum (T1 and T2), B. tequilensis (T3, T5, T7, T8, and T19), and B. spizizenii (T6). Biological and molecular assays confirmed that these strains could induce the expression of genes associated with antimicrobial compounds like iturin, fengycin, subtilosin, and alkaline protease, which effectively reduced the disease index of tea anthracnose and enhanced tea plant growth. In conclusion, this study demonstrates that B. inaquosorum, B. tequilensis, and B. spizizenii strains are promising biocontrol agents for managing tea anthracnose.

An mRNA methylase and demethylase regulate sorghum salt tolerance by mediating N6-methyladenosine modification.

N 6-methyladenosine (m6A) modification is a crucial and widespread molecular mechanism governing plant development and stress tolerance. The specific impact of m6A regulation on plants with inherently high salt tolerance remains unclear. Existing research primarily focuses on the overexpression or knockout of individual writer or eraser components to alter m6A levels. However, a comprehensive study simultaneously altering overall m6A modification levels within the same experiment is lacking. Such an investigation is essential to determine whether opposing changes in m6A modification levels exert entirely different effects on plant salt tolerance. In this study, we identified the major writer member mRNA adenosine methylase A (SbMTA) in sorghum (Sorghum bicolor) as critical for sorghum survival. The sbmta mutant exhibits a phenotype characterized by reduced overall m6A, developmental arrest, and, ultimately, lethality. Overexpression of SbMTA increased m6A levels and salt tolerance, while overexpression of the m6A eraser alkylated DNA repair protein AlkB homolog 10B (SbALKBH10B) in sorghum showed the opposite phenotype. Comparative analyses between sorghum with different m6A levels reveal that SbMTA- and SbALKBH10B-mediated m6A alterations significantly impact the stability and expression levels of genes related to the ABA signaling pathway and growth under salt stress. In summary, this study unveils the intricate relationship between m6A modifications and salt tolerance in sorghum, providing valuable insights into how m6A modification levels on specific transcripts influence responses to salt stress.

Genome-Wide Identification of the Maize Chitinase Gene Family and Analysis of Its Response to Biotic and Abiotic Stresses

Background/Objectives: Chitinases, enzymes belonging to the glycoside hydrolase family, play a crucial role in plant growth and stress response by hydrolyzing chitin, a natural polymer found in fungal cell walls. This study aimed to identify and analyze the maize chitinase gene family, assessing their response to various biotic and abiotic stresses to understand their potential role in plant defense mechanisms and stress tolerance. Methods: We employed bioinformatics tools to identify 43 chitinase genes in the maize B73_V5 genome. These genes were characterized for their chromosomal positions, gene and protein structures, phylogenetic relationships, functional enrichment, and collinearity. Based on previous RNA-seq data, the analysis assessed the expression patterns of these genes at different developmental stages and under multiple stress conditions. Results: The identified chitinase genes were unevenly distributed across maize chromosomes with a history of tandem duplications contributing to their divergence. The ZmChi protein family was predominantly hydrophilic and localized mainly in chloroplasts. Expression analysis revealed that certain chitinase genes were highly expressed at specific developmental stages and in response to various stresses, with ZmChi31 showing significant responsiveness to 11 different abiotic and biotic stresses. Conclusions: This study provides new insights into the role of chitinase genes in maize stress response, establishing a theoretical framework for exploring the molecular basis of maize stress tolerance. The identification of stress-responsive chitinase genes, particularly ZmChi31, offers potential candidates for further study in enhancing maize resistance to environmental challenges.

Cloning, sequence analysis, and functional study of the PeDof-4 gene in response to drought stress

DNA-binding with one finger (Dof) was a functionally important gene in plant stress tolerance processes. The cloned full-length (849bp) passion fruit PeDof-4 gene was sequenced, which encodes 282 amino acids with the molecular formula C1274H1983N375O408S14, molecular weight 29529.87 u, and theoretical isoelectric point pI of 8.96. Evolutionary tree analysis showed that the PeDof-4-encoded proteins had a high degree of identity with Dof-encoded proteins in other plants. Blastp of the PeDof-4 encoded proteins revealed a closer affinity to the proteins encoded by the Dof of Theobroma cacao. The relative expression of the PeDof-4 gene was higher at 50% of the relative soil moisture content in the fluorescence qPCR experiments under different levels of drought stress. Tissue-specific analysis showed that the highest expression of this gene was found in the roots. Overexpression of GUS gene under the PeDof-4 promoter inbidopsis thaliana showed that PeDof-4 could significantly respond to drought stress. Bangladesh J. Bot. 52(3): 653-663, 2024 (September) Special

Rhizosheath Formation and Its Role in Plant Adaptation to Abiotic Stress

The rhizosheath, the layer of soil tightly attached to the roots, protects plants against abiotic stress and other adverse conditions by providing a bridge from the plant root system to the soil. It reduces the formation of air gaps between the root and soil and facilitates the transportation of water at the root–soil interface. It also serves as a favourable niche for plant-growth-promoting rhizobacteria in the surrounding soil, which facilitate the absorption of soil water and nutrients. This review compares the difference between the rhizosheath and rhizosphere, and summarises the molecular and physiological mechanisms of rhizosheath formation, and identifying the causes of rhizosheath formation/non-formation in plants. We summarise the chemical and physical factors (root hair, soil-related factors, root exudates, and microorganisms) that determine rhizosheath formation, and focus on the important functions of the rhizosheath in plants under abiotic stress, especially in drought stress, phosphorus deficiency, aluminium stress, and salinity stress. Understanding the roles played by the rhizosheath and the mechanisms of its formation provides new perspectives for improving plant stress tolerance in the field, which will mitigate the increasing environmental stress conditions associated with on-going global climate change.

Diethyl aminoethyl hexanoate reprogramed accumulations of organic metabolites associated with water balance and metabolic homeostasis in white clover under drought stress.

Diethyl aminoethyl hexanoate (DA-6) serving as a non-toxic and low-cost plant growth regulator is used for improving plant growth and stress tolerance, but the DA-6-mediated organic metabolites remodeling in relation to drought tolerance is not well documented in crops. The aims of the present study were to evaluate impacts of DA-6 on physiological functions including osmotic adjustment, photochemical efficiency, oxidative damage, and cell membrane stability as well as organic metabolites remodeling in white clover (Trifolium repens) leaves based on the analysis of metabolomics. Plants were foliarly treated with or without DA-6 and subsequently exposed to drought stress for 8 days. Results demonstrated that foliar application of DA-6 (1.5 mM) could significantly ameliorate drought tolerance, which was linked with better leaf water status, photosynthetic performance, and cell membrane stability as well as lower oxidative injury in leaves. Metabolic profiling of organic metabolites identified a total of 59 metabolites including 17 organic acids, 20 sugars, 12 alcohols, and 10 other metabolites. In response to drought stress, the DA-6 induced accumulations of many sugars and sugar alcohols (erythrulose, arabinose, xylose, inosose, galactose, talopyranose, fucose, erythritol, and ribitol), organic acids (propanoic acid, 2,3-dihydroxybutanoic acid, palmitic acid, linolenic acid, and galacturonic acid), and other metabolites (2-oxazoline, silane, and glycine) in white clover. These altered metabolites induced by the DA-6 could perform critical functions in maintenances of osmo-protection, osmotic adjustment, redox homeostasis, cell wall structure and membrane stability when white clover suffered from water deficit. In addition, the campesterol and stigmasterol significantly accumulated in all plants in spite of the DA-6 pretreatment under drought stress, which could be an important adaptive response to water deficit due to beneficial roles of those two metabolites in regulating cell membrane stability and antioxidant defense. Present findings provide new evidence of DA-6-regulated metabolic homeostasis contributing to drought tolerance in leguminous plants.

Phosphoproteome modulation by nucleoside diphosphate kinase affects photosynthesis & stress tolerance of Nostoc PCC 7120

Nucleoside diphosphate kinase (Ndk/NDK/NDPK) is known to possess pleiotropic functions, one of which is that as a protein kinase, and has been shown to be involved in stress tolerance in plants. To assess its role in the cyanobacterium Nostoc PCC 7120, which is hitherto unreported, recombinant strain overexpressing Ndk, Anndk+ was generated. Phosphoproteomic analysis of Anndk+ and its comparison with that of the vector control, AnpAM, revealed differential phosphorylation at S/T/Y sites of proteins belonging to varied functional groups, with over 17 % phosphoproteins involved in photosynthesis. A total of 177 phosphopeptides and 117 phosphoproteins were identified, including newly identified phosphopeptides in any cyanobacteria. Compared to AnpAM, the Anndk+ cells exhibited (i) lower photosynthetic efficiency and electron transport rate at low PAR (photosynthetically active radiation), (ii) no change in photochemical quenching across PAR, (iii) but distinct non-photochemical quenching [zero Y(NPQ) and high Y(NO) in Anndk+ and high Y(NPQ) and low (NO) in AnpAM], and (iv) increased tolerance to γ-radiation, oxidative, salt and DCMU stresses. The observed modulation of phosphoproteome linked to physiological changes upon overexpression of Ndk in Nostoc could be a combination of direct protein kinase activity of Ndk and/or indirectly through other protein kinases and phosphatases whose phosphorylation status is mediated by Ndk. This is the first report on a direct correlation between Ndk levels, phosphorylation status of proteins and stress tolerance in any cyanobacteria.

Biomolecular condensates mediate bending and scission of endosome membranes

Multivesicular bodies are key endosomal compartments implicated in cellular quality control through their degradation of membrane-bound cargo proteins1–3. The ATP-consuming ESCRT protein machinery mediates the capture and engulfment of membrane-bound cargo proteins through invagination and scission of multivesicular-body membranes to form intraluminal vesicles4,5. Here we report that the plant ESCRT component FREE16 forms liquid-like condensates that associate with membranes to drive intraluminal vesicle formation. We use a minimal physical model, reconstitution experiments and in silico simulations to identify the dynamics of this process and describe intermediate morphologies of nascent intraluminal vesicles. Furthermore, we find that condensate-wetting-induced line tension forces and membrane asymmetries are sufficient to mediate scission of the membrane neck without the ESCRT protein machinery or ATP consumption. Genetic manipulation of the ESCRT pathway in several eukaryotes provides additional evidence for condensate-mediated membrane scission in vivo. We find that the interplay between condensate and machinery-mediated scission mechanisms is indispensable for osmotic stress tolerance in plants. We propose that condensate-mediated scission represents a previously undescribed scission mechanism that depends on the physicomolecular properties of the condensate and is involved in a range of trafficking processes. More generally, FREE1 condensate-mediated membrane scission in multivesicular-body biogenesis highlights the fundamental role of wetting in intracellular dynamics and organization.

Enhancing Citrus Resilience: Strategies and Advances in Abiotic Stress Management: A Review

Citrus, a major global agricultural crop is highly valued for its nutritional benefits and widespread consumption. However, as a subtropical plant, citrus is particularly sensitive to abiotic stresses such as salinity, drought, waterlogging, nutrient deficiency, high irradiance and cold temperatures. These stresses pose significant challenges to citriculture, reducing yield and fruit quality. Traditional methods like rootstock selection and plant breeding have been used to improve stress tolerance to some extent. Recent advancements in genetic engineering and biotechnology have enhanced our understanding of the molecular mechanisms behind stress tolerance. Identifying and isolating specific genes and transcription factors have led to novel agricultural practices that economically benefit citriculture and mitigate the adverse effects of abiotic stress. This review paper emphasizes and summarises the citrus responses to abiotic stress and strategies developed to enhance stress tolerance in citrus plants.

Harnessing the potential of copper-based nanoparticles in mitigating abiotic and biotic stresses in crops.

The demand for crops production continues to intensify with the rapid increase in population. Agricultural crops continue to encounter abiotic and biotic stresses, which can substantially hamper their productivity. Numerous strategies have been focused to tackle the abiotic and biotic stress factors in various plants. Nanotechnology has displayed great potential to minimize the phytotoxic impacts of these environmental constraints. Copper (Cu)-based nanoparticles (NPs) have displayed beneficial effects on plant growth and stress tolerance. Cu-based NPs alone or in combination with plant growth hormones or microorganisms have been documented to induce plant tolerance and mitigate abiotic or biotic stresses in different plants. In this review, we have comprehensively discussed the uptake and translocation of Cu-based NPs in plants, and beneficial roles in improving the plant growth and development at various growth stages. Moreover, we have discussed how Cu-based NPs mechanistically modulate the physiological, biochemical, metabolic, cellular, and metabolic functions to enhance plant tolerance against both biotic (viruses, bacterial and fungal diseases, etc.) and abiotic stresses (heavy metals or metalloids, salt, and drought stress, etc.). We elucidated recent advancements, knowledge gaps, and recommendations for future research. This review would help plant and soil scientists to adapt Cu-based novel strategies such as nanofertilizers and nanopesticides to detoxify the abiotic or biotic stresses. These outcomes may contribute to the promotion of healthy food production and food security, thus providing new avenues for sustainable agriculture production.

Evaluation of oxidative stress, biochemical parameters and in silico markers in different pea accessions in response to drought stress.

ARG6 and ARG10 pea accessions exhibited better tolerance to drought by keeping drought-associated attributes stable and higher, that is, stable chlorophyll content, high antioxidant activity, and the presence of polymorphic bands with stress-responsive EST-SSR markers. Each year, a significant portion of crops is lost due to various abiotic stresses, and even pea (Pisum sativum) crop growth and yield are severely affected by the challenges posed by drought stress. Drought is a critical factor that limits crop growth and development, and its impact is exacerbated by changes in the magnitude of climatic conditions. Drought induces oxidative stress in plants, leading to the accumulation of high concentrations of reactive oxygen species that damage cell structures and vital functioning of cells. The primary objective was to identify stress-tolerant plants by evaluating different morphological and biochemical attributes, such as biomass, chlorophyll content, relative water content, ascorbate peroxidase (APX), superoxide dismutase (SOD), and DPPH scavenging activity, as well as protein, proline, and phenolic content. Our study revealed that pea accessions (ARG6 and ARG10) were more resilient to drought stress as their chlorophyll, relative water, protein, and proline contents increased under drought conditions. Antioxidant enzymes, such as SOD, APX, and DPPH activities, also increased under drought stress in ARG10 and ARG6, suggesting that these accessions could bolster the antioxidant defense system in response to drought stress. Based on putative (cellular, biological, and metabolic) functions, ten EST-SSR primers were selected for the amplification study. Three EST-SSR primers, AUMP06_110, AUMP18_300, and AUMP31_250, were used for ARG6 and ARG10. Based on the correlation between the presence or absence of specific EST-SSR alleles, various physiological and morphological traits, and DPPH scavenging activity, both ARG10 and ARG6 demonstrated resistance to drought stress.

Complexity of influences on atrazine phytoremediation of coexisting graphene oxide in water: Mitigating its phytotoxicity while decreasing plant removal contribution

Phytoremediation is an efficient technology for the removal of herbicide atrazine (ATZ) contamination in water bodies, but its ability to reduce ATZ under combined pollution remains unclear, especially ATZ co-existing with the emerging pollutant graphene oxide (GO) that may have potential effects on ATZ fate, plants and microbes. Herein, we investigated the phytoremediation potential of an emergent plant (Iris pseudacorus) for ATZ and the response of bacteria in a hydroponic system with and without GO. The results showed that plants enhanced ATZ dissipation in water with the increased removal rate by a factor of 1.7–4.0. GO restricted ATZ uptake by plants, but favored ATZ bioconcentration in cell walls. The plant contributed most to changes in the bacterial communities, decreasing the alpha diversity, while enriching the functional categories involving in amino acid and carbohydrate metabolisms. These findings indicated that I. pseudacorus can be employed as an effective candidate of phytoremediation for ATZ co-existing with GO at environmentally relevant concentrations, tending to recruit bacteria with plant stress tolerance and growth-promotion activities more than with ATZ degradation activities; GO exerted a mitigating effect on ATZ stress improving the barrier function of cell walls, but decreased the contribution of plants to ATZ removal.

Genome-wide identification and gene expression networks of LBD transcription factors in Populus trichocarpa

The Lateral Organ Boundaries Domain (LBD) proteins, an exclusive family of transcription factors (TFs) found solely in plants, play pivotal roles in lateral organogenesis, stress adaptation, secondary growth, and hormonal signaling responses. In this study, a total of 55 PtLBD TFs from Populus trichocarpa were identified and systematically classified into two subfamilies, designated as subfamily-I and subfamily-II with seven distinct groups based on phylogenetic analysis. Gene structure detection indicated that the difference of phase numbers linking adjacent exons contribute to the variations in splicing patterns among different PtLBD groups. Numerous transcription factor binding sites and cis-elements pertinent to hormone signaling pathways and stress response mechanisms were identified within the upstream promoter regions of the PtLBD genes. Thirty-five PtLBDs were found to be engaged in either tandem or segmental duplications, and genomic collinearity analysis revealed a stronger alignment between PtLBD genes and eudicots plants compared to their relationship with monocots. GO enrichment and temporal-spatio expression patterns showed that PtLBD7 from subfamily-I and PtLBD20 from subfamily-II, along with other 13 PtLBDs, were involved in plant growth and development biological processes. The multilayered hierarchical gene networks (ML-hGRN) mediated by PtLBD7 and PtLBD20 indicated that PtLBDs were mainly function in poplar growth and stress tolerance through a multifaceted and intricate regulatory machinery. This study lays a solid groundwork for delving deeper into the roles and underlying mechanisms of LBD transcription factors in poplar, specifically those related to plant hormones and stress tolerance.

Simultaneous mutations in ITPK4 and MRP5 genes result in a low phytic acid level without compromising salt tolerance in Arabidopsis.

Generation of crops with low phytic acid (myo-inositol-1,2,3,4,5,6-hexakisphosphate (InsP6)) is an important breeding direction, but such plants often display less desirable agronomic traits. In this study, through ethyl methanesulfonate-mediated mutagenesis, we found that inositol 1,3,4-trisphosphate 5/6-kinase 4 (ITPK4), which is essential for producing InsP6, is a critical regulator of salt tolerance in Arabidopsis. Loss of function of ITPK4 gene leads to reduced root elongation under salt stress, which is primarily because of decreased root meristem length and reduced meristematic cell number. The itpk4 mutation also results in increased root hair density and increased accumulation of reactive oxygen species during salt exposure. RNA sequencing assay reveals that several auxin-responsive genes are down-regulated in the itpk4-1 mutant compared to the wild-type. Consistently, the itpk4-1 mutant exhibits a reduced auxin level in the root tip and displays compromised gravity response, indicating that ITPK4 is involved in the regulation of the auxin signaling pathway. Through suppressor screening, it was found that mutation of Multidrug Resistance Protein 5 (MRP5)5 gene, which encodes an ATP-binding cassette (ABC) transporter required for transporting InsP6 from the cytoplasm into the vacuole, fully rescues the salt hypersensitivity of the itpk4-1 mutant, but in the itpk4-1 mrp5 double mutant, InsP6 remains at a very low level. These results imply that InsP6 homeostasis rather than its overall amount is beneficial for stress tolerance in plants. Collectively, this study uncovers a pair of gene mutations that confer low InsP6 content without impacting stress tolerance, which offers a new strategy for creating "low-phytate" crops.

Endophytic bacilli from Cyamopsis tetragonoloba (L.) Taub. induces plant growth and drought tolerance.

Cyamopsis tetragonoloba (L.) Taub. (guar) is a commercially important crop known for its galactomannan content in seeds. Drought stress is a significant global concern that compromises the productivity of major legumes including guar. The endophytic microbes associated with plants play a significant role in enhancing plant growth and modulating the impact of abiotic stress(s). The present study involved the isolation of 73 endophytic bacteria from the guar seeds of drought-tolerant (RGC-1002 and RGC-1066) and sensitive (Sarada and Varsha) varieties. Based on multiple PGP attributes and drought tolerance, at 50% PEG6000 w/v, 11 efficient isolates were selected and identified through 16S rRNA gene sequencing. Isolates belonging to ten different species of bacilli including Cytobacillus oceanisediminis, Mesobacillus fermenti, Peribacillus simplex from sensitive and Bacillus zanthoxyli, B. safensis, B. velezensis, B. altitudinis, B. licheniformis, B. tequilensis, and B. paralicheniformis isolated from tolerant varieties. A greenhouse experiment with a drought-sensitive guar variety demonstrated that inoculation of selected isolates showed comparatively better plant growth, higher relative water content (RWC), decreased carbon isotope discrimination ratio (Δ13C), increased chlorophyll, carotenoids, anthocyanin, and proline content, decreased malondialdehyde (MDA) and modulated defense enzymes as compared to their uninoculated controls. Tolerant variety isolates B. tequilensis NBRI14G and B. safensis NBRI10R showed the most promising results in improving plant growth and also drought stress tolerance in guar plants. This study represents for the first time that seed endophytic bacterial strains from guar can be utilized to develop the formulation for improving the productivity of guar under drought-stress conditions.

Small chemical molecules regulating the phytohormone signalling alter the plant's physiological processes to improve stress adaptation, growth and productivity.

Small chemical molecules are attractive agents for improving the plant processes associated with plant growth and stress tolerance. Recent advances in chemical biology and structure-assisted drug discovery approaches have opened up new avenues in plant biology to discover new drug-like molecules to improve plant processes for sustained food production. Several compounds targeting phytohormone biosynthesis or signalling cascades were designed to alter plant physiological mechanisms. Altering Abscisic acid synthesis and its signalling process can improve drought tolerance, and the processes targeted are reversible. Molecules targeting cytokinin, Auxin, and gibberellic acid regulate plant physiological processes and can potentially improve plant growth, biomass and productivity. The potential of molecules may be exploited as agrochemicals to enhance agricultural productivity. The discovery of small molecules provides new avenues to improve crop production in changing climatic conditions and the nutritional quality of foods. We present the rational combinations of small molecules with inhibitory and co-stimulatory effects and discuss future opportunities in this field.

Genome-wide identification and expression analysis of the U-box gene family related to biotic and abiotic stresses in Coffea canephora L.

Plant U-box genes play an important role in the regulation of plant hormone signal transduction, stress tolerance, and pathogen resistance; however, their functions in coffee (Coffea canephora L.) remain largely unexplored. In this study, we identified 47 CcPUB genes in the C. canephora L. genome, clustering them into nine groups via phylogenetic tree. The CcPUB genes were unevenly distributed across the 11 chromosomes of C. canephora L., with the majority (11) on chromosome 2 and none on chromosome 8. The cis-acting elements analysis showed that CcPUB genes were involved in abiotic and biotic stresses, phytohormone responsive, and plant growth and development. RNA-seq data revealed diverse expression patterns of CcPUB genes across leaves, stems, and fruits tissues. qRT-PCR analyses under dehydration, low temperature, SA, and Colletotrichum stresses showed significant up-regulation of CcPUB2, CcPUB24, CcPUB34, and CcPUB40 in leaves. Furthermore, subcellular localization showed CcPUB2 and CcPUB34 were located in the plasma membrane and nucleus, and CcPUB24 and CcPUB40 were located in the nucleus. This study provides valuable insights into the roles of PUB genes in stress responses and phytohormone signaling in C. canephora L., and provided basis for functional characterization of PUB genes in C. canephora L.

Cerium oxide nanoparticles promoted lateral root formation in Arabidopsis by modulating reactive oxygen species and Ca2+ level.

Roots play an important role in plant growth, including providing essential mechanical support, water uptake, and nutrient absorption. Nanomaterials play a positive role in improving plant root development, but there is limited knowledge of how nanomaterials affect lateral root (LR) formation. Poly (acrylic) acid coated nanoceria (cerium oxide nanoparticles, PNC) are commonly used to improve plant stress tolerance due to their ability to scavenge reactive oxygen species (ROS). However, its impact on LR formation remains unclear. In this study, we investigated the effects of PNC on LR formation in Arabidopsis thaliana by monitoring ROS levels and Ca2+ distribution in roots. Our results demonstrate that PNC significantly promote LR formation, increasing LR numbers by 26.2%. Compared to controls, PNC-treated Arabidopsis seedlings exhibited reduced H2 O2 levels by 18.9% in primary roots (PRs) and 40.6% in LRs, as well as decreased O 2 · - levels by 47.7% in PRs and 88.5% in LRs. When compared with control plants, Ca2+ levels were reduced by 35.7% in PRs and 22.7% in LRs of PNC-treated plants. Overall, these results indicate that PNC could enhance LR development by modulating ROS and Ca2+ levels in roots.