Search

Climate change, particularly temperature fluctuations, profoundly impacts pest populations. This study focuses on the tomato, a crucial commercial crop in the Eastern Himalayan Region of India. The study examined the impact of varying thermal regimes on tomato fruit borers. Field experiments were conducted at three locations, with altitudes ranging from < 500 to > 1500 m. At lower altitudes, fruit borer incidence commenced earlier (5th − 18th March) and peaked higher (1.47 ± 0.34 to 1.73 ± 0.37 larvae/plant), causing more damage (26–29%) as compared to the highest location (~ 9%). The generalized linear mixed model (GLMM) analysis indicated that maximum temperature had significant positive impacts on the H. armigera incidence and fruit damage. Climatic datasets indicate an increase in the temperature of the region during the tomato growing season, thereby increasing the risk of fruit borer impact. As an adaptation option, we evaluated eight different tomato varieties/genotypes and studied biochemical parameters to understand their tolerance. Results showed a strong positive association of fruit borer incidence with total soluble solids whereas negative association with acidity. Cherry tomato (7.62%) and MT-2 (10.04%) had relatively lower fruit damage; MT-3 (50.92 t/ha) and MT-2 (50.57 t/ha) consistently yielded the highest across all locations. Hence, the selection of appropriate genotypes and the development of varieties with suitable characteristics hold the key to fruit borer management. This insight is crucial for developing effective pest management strategies and ensuring sustainable agricultural practices in the region. [ABSTRACT FROM AUTHOR]

Reactive oxygen species (ROS) and reactive nitrogen species (RNS) are critical for plant development as well as for its stress response. They can function as signaling molecules to orchestrate a well-defined response of plants to biotic stress. These responses are further fine-tuned by phytohormones, such as salicylic acid, jasmonic acid, and ethylene, to modulate immune response. In the past decades, the intricacies of redox and phytohormonal signaling have been uncovered during plant–pathogen interactions. This review explores the dynamic interplay of these components, elucidating their roles in perceiving biotic threats and shaping the plant's defense strategy. Molecular regulators and sites of oxidative burst have been explored during pathogen perception. Further, the interplay between various components of redox and phytohormonal signaling has been explored during bacterial, fungal, viral, and nematode infections as well as during insect pest infestation. Understanding these interactions highlights gaps in the current knowledge and provides insights into engineering crop varieties with enhanced resistance to pathogens and pests. This review also highlights potential applications of manipulating regulators of redox signaling to bolster plant immunity and ensure global food security. Future research should explore regulators of these signaling pathways as potential target to develop biotic stress-tolerant crops. Further insights are also needed into roles of endophytes and host microbiome modulating host ROS and RNS pool for exploiting them as biocontrol agents imparting resistance against pathogens in plants. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Autophagy is a preserved process in eukaryotes that allows large material degeneration and nutrient recovery via vacuoles or lysosomes in cytoplasm. Autophagy starts from the moment of induction during the formation of a phagophore. Degradation may occur in the autophagosomes even without fusion with lysosome or vacuole, particularly in microautophagosomes. This process is arbitrated by the conserved machinery of basic autophagy‐related genes (ATGs). In selective autophagy, specific materials are recruited by autophagosomes via receptors. Selective autophagy targets a vast variety of cellular components for degradation, i.e., old or damaged organelles, aggregates, and inactive or misfolded proteins. In optimal conditions, autophagy in plants ensures cellular homeostasis, proper plant growth, and fitness. Moreover, autophagy is essential during stress responses in plants and aids in survival of plants. Several biotic and abiotic stresses, i.e., pathogen infection, nutrient deficiency, plant senescence, heat stress, drought, osmotic stress, and hypoxia induce autophagy in plants. Cell death is not a stress, which induces autophagy but in contrast, sometimes it is a consequence of autophagy. In this way, autophagy plays a vital role in plant survival during harsh environmental conditions by maintaining nutrient concentration through elimination of useless cellular components. This review discussed the recent advances regarding regulatory functions of autophagy under normal and stressful conditions in plants and suggests future prospects in mitigating climate change. Autophagy in plants offers a viable way to increase plant resilience to climate change by increasing stress tolerance and nutrient usage efficiency. [ABSTRACT FROM AUTHOR]

This study assessed the efficacy of chitosan, methyl jasmonate, and silicon in the reduction of disease severity and the induction of defense responses in common bean plants against angular leaf spot caused by Pseudocercospora griseola. The expression level of several pathogenesis-related (PR) proteins, PR1, PR2 (β-1,3-glucanase), and PR3 (chitinase), and defense-related enzymes, phenylalanine ammonia-lyase, peroxidase, and lipoxygenase, was analyzed at different time points in common bean plants after different treatments. Elicitor treatments significantly reduced disease severity 21 days after inoculation, with silicon at a 2 mM concentration proving most effective with 38.93% disease control, followed by 1 mM MeJA and 2% chitosan, respectively. Treatments with chitosan, methyl jasmonate, and silicon, regardless of pathogen infection, significantly elevated PR1, PR2, and PR3 gene expressions at 48 h after inoculation (hpi). PAL and POD activities were similarly increased following elicitor treatments and pathogen infection, especially at 48 hpi. Chemical elicitors applied post-inoculation induced PR proteins, PAL, and POD enzyme activities at 48 hpi, while LOX activity exhibited a variable fluctuation with treatments. These findings suggested that chemical elicitors, especially silicon, were effective in reducing ALS disease severity in common beans, with improved resistance associated with the expression of pathogen-responsive genes. This study is the first to analyze the expression profiles of defense-related genes in common beans treated with chemical elicitors prior to P. griseola infection. [ABSTRACT FROM AUTHOR]

Introduction: The production of high-quality food for the growing world population on the one hand and the reduction of chemical-synthetic pesticides on the other hand represents a major challenge for agriculture worldwide. The effectiveness of a combination of microbial and non-microbial biostimulants (BSs) with various nitrogen (N) forms in pathogen defense is discussed as a promising, but still poorly understood bio-based alternative for crop protection. Methods: For this reason, nitrate and stabilized ammonium fertilizer both combined with a consortium of Pseudomonas brassicacearum, Bacillus amyloliquefaciens, and Trichoderma harzianum as soil treatment or with a mixture of seaweed extract (Ascophyllum nodosum) together with chitosan-amended micronutrient fertilizer as foliar spray application were compared under controlled greenhouse conditions. Furthermore, a combination of microbial and different non-microbial BSs (seaweed extracts + chitosan) and micronutrients with nitrate or with stabilized ammonium fertilizer was tested under field conditions to improve nutrient availability, promote plant growth, and suppress Zymoseptoria tritici (Zt) in winter wheat. Results and discussion: While plant-protective effects against Zt by the microbial consortium application could be observed particularly under ammonium fertilization, the application of seaweed extract-chitosan mixture expressed plant defense against Zt more strongly under nitrate fertilization. In the field trial, the combination of microbial consortium with the seaweed extract-chitosan mixture together with micronutrients zinc (Zn) and manganese (Mn) showed positive effects against Zt under ammonium fertilization, associated with increased levels of defense metabolites. Furthermore, the additional input of Zn and copper (Cu) from the chitosan application improved the micronutrient status by minimizing the risk of Zn and Cu deficiency under controlled and field conditions. The use of BSs and the inoculation of Zt did not show any effects on plant growth and yield neither under controlled greenhouse conditions nor in the field. Summarized, microbial and non-microbial BSs separately applied or even combined together as one treatment did not influence plant growth or yield but made a positive contribution to an N form-dependent promotion of pathogen defense. [ABSTRACT FROM AUTHOR]

Phytoplasmas are phytopathogenic bacteria that cause serious damage to agriculture. A quarantine pathogen, the flavescence dorée phytoplasma (FDp), often associated with grapevine yellows disease, affects viticultural production across Europe. However, the mechanisms of FDp pathogenicity are not still elucidated. In this study, symptomatic and asymptomatic grapevine (Vitis vinifera L. var. 'Pinot gris') leaves were sampled. Two different FDp genotypes (M38 and M54) were identified, and genotype-dependent changes to grapevine physiological responses through the development of FDp infection were analysed. Correlation analyses established a potential link between measured physiological parameters and relative FDp DNA abundance. Increased malondialdehyde levels pointed to the oxidative stress in infected leaves, and highly correlated with the activation of L-ascorbic acid synthesis. Levels of hydrogen peroxide were reduced in infected leaves, possibly as an FDp mechanism to avoid plant-derived oxidative damage. Genotype M54 was associated with a lower accumulation of soluble sugars and lower damage to photosynthetic pigments while retaining a higher titre than M38. Therefore, pronounced phytoplasma genotype-dependent changes in grapevine physiology, potentially caused by the differences between M54 and M38 on the level of the efficiency of their effectors should be further investigated. Altogether, results provide data on certain targets of FDp in grapevine and could assist in the identification of potential specific effectors of this phytoplasma to aid the efforts of FDp management in European vineyards. [ABSTRACT FROM AUTHOR]

Abiotic and biotic stress factors seriously affect plant growth and development. The process of plant response to abiotic stress involves the synergistic action of multiple resistance genes. The ASR (Abscisic acid stress-ripening) gene is a plant-specific transcription factor that plays a central role in regulating plant senescence, fruit ripening, and response to abiotic stress. ASR family members are highly conserved in plant evolution and contain ABA/WBS domains. ASR was first identified and characterized in tomatoes (Solanum lycopersicum L.). Subsequently, the ASR gene has been reported in many plant species, extending from gymnosperms to monocots and dicots, but lacks orthologues in Arabidopsis (Arabidopsis thaliana). The promoter regions of ASR genes in most species contain light-responsive elements, phytohormone-responsive elements, and abiotic stress-responsive elements. In addition, ASR genes can respond to biotic stresses via regulating the expression of defense genes in various plants. This review comprehensively summarizes the evolutionary history, gene and protein structures, and functions of the ASR gene family members in plant responses to salt stress, low temperature stress, pathogen stress, drought stress, and metal ions, which will provide valuable references for breeding high-yielding and stress-resistant plant varieties. [ABSTRACT FROM AUTHOR]

AbstractIn eukaryotes, general transcription factors (GTFs) enable recruitment of RNA polymerase II (RNA Pol II) to core promoters to facilitate initiation of transcription. Extensive research in mammals and yeast has unveiled their significance in basal transcription as well as in diverse biological processes. Unlike mammals and yeast, plant GTFs exhibit remarkable degree of variability and flexibility. This is because plant GTFs and GTF subunits are often encoded by multigene families, introducing complexity to transcriptional regulation at both cellular and biological levels. This review provides insights into the general transcription mechanism, GTF composition, and their cellular functions. It further highlights the involvement of RNA Pol II-related GTFs in plant development and stress responses. Studies reveal that GTFs act as important regulators of gene expression in specific developmental processes and help equip plants with resilience against adverse environmental conditions. Their functions may be direct or mediated through their cofactor nature. The versatility of GTFs in controlling gene expression, and thereby influencing specific traits, adds to the intricate complexity inherent in the plant system. [ABSTRACT FROM AUTHOR]

Insect infestation triggers multiple defense responses in plants, both locally at the infection site and systemically throughout the plant, including the production of feeding deterrents, toxins, defensive proteins, enzymes, and secondary metabolites. Our study aimed to compare the endogenous levels of antioxidative enzymes, photosynthetic pigments, phytohormones, total phenols, and flavonoids in bark-beetle-infested and uninfested trees. We evaluated the surviving trees in bark-beetle-infested stands, assessing both the condition and defense of uninfested and infested beech (Fagus sylvatica), pine (Pinus sylvestris), and fir (Abies alba) trees. Sampling was performed at six affected sites in the Czech Republic, targeting trees that were resilient to significant health deterioration caused by abiotic and biotic factors. The results showed different levels of most of the measured compounds in the three species. Among all the tested species, photosynthetic pigment levels showed the strongest association with infestation status, which was generally lower in the infested plants. For chlorophyll a, extremely significant reductions were observed from 123 ± 20.6 to 101 ± 17.9 μg/g dry weight (DW) in pine, from 231 ± 33.1 to 199 ± 22.2 μg/g DW in beech, and from 60 ± 5.66 to 51.3 ± 6.27 μg/g DW in fir. In contrast, enzymatic activities indicated only isolated instances of significant association, whereas antioxidative properties (total phenolic content, flavonoids, and 2,2-diphenyl-1-picrylhydrazyl radical scavenging capacity) were not significantly associated with infestation status. There was a statistically significant increase in glutathione reductase activity in infested fir and pine trees. However, this difference was not statistically significant in beech. In contrast, a significant increase in superoxide dismutase activity was detected in infected beech trees. Phytohormones have emerged as the most diverse group of analyzed compounds. Cytokinins were the most distinct, with many of them being significantly increased in infested pines, whereas both beech and fir showed only one significant association. Additionally, derivatives of jasmonic acid also showed a distinct pattern of change associated with bark beetle infestation, with the levels of three out of the four analyzed jasmonates being significantly decreased in infested pines, whereas no effects were observed in beeches and firs. Notably, many phytohormones were significantly elevated in the infested pine, whereas both beech and fir exhibited only one significant association. Overall, the data showed that pines responded differently to bark beetles than to beeches or firs. The greatest changes in phytohormones were observed in pine, whereas the most significant changes in photosynthetic pigments were observed in beech and fir trees. [ABSTRACT FROM AUTHOR]

The Defective in Induced Resistance 1 (DIR1) gene, a member of the lipid transferase proteins (LTPs), plays a crucial role in plant defense against pathogens. While previous transcriptomic studies have highlighted the significant expression of citrus LTPs during biotic stress, functional annotations of LTPs in the Citrus genera remain limited. In this study, we cloned the Murraya paniculata DIR1 (MpDIR1(t)) gene and overexpressed it in Arabidopsis thaliana to evaluate its stress response mechanisms against biotic stress. The transgenic Arabidopsis lines showed fewer disease symptoms in response to Pseudomonas syringae (Pst DC3000) compared to wild-type Arabidopsis. Defense and pathogenesis-responsive genes such as PR1, PR4, PR5, and WRKY12 were significantly induced, showing a 2- to 12-fold increase in all transgenic lines compared to the wild type. In addition, the Pst DC3000-infected transgenic Arabidopsis lines demonstrated elevated levels of flavonoids and salicylic acid (SA), along with higher expression of SA-related genes, compared to the wild type. Moreover, all transgenic lines possessed lower reactive oxygen species levels and higher activity of antioxidant defense enzymes such as superoxide dismutase, peroxidase, and catalase under Pst DC3000 stress compared to the wild type. The up-regulation of defense genes, activation of the SA pathway, accumulation of flavonoids, and reinforcement of antioxidant defense mechanisms in transgenic Arabidopsis lines in response to Pst DC3000 underscore the critical role of MpDIR1(t) in fortifying plant immunity. Thus, MpDIR1(t) constitutes a promising candidate gene for improving bacterial disease resistance in commercial citrus cultivars. [ABSTRACT FROM AUTHOR]

DNA methylation is environment-sensitive and can mediate stress responses. In trees, changes in the environment might cumulatively shape the methylome landscape over time. However, because high-resolution methylome studies usually focus on single environmental cues, the stress-specificity and long-term stability of methylation responses remain unclear. Here, we studied the methylome plasticity of a Populus nigra cv. 'Italica' clone widely distributed across Europe. Adult trees from different geographic locations were clonally propagated in a common garden experiment and exposed to cold, heat, drought, herbivory, rust infection, and salicylic acid treatments. Whole-genome bisulfite sequencing revealed stress-induced and naturally occurring DNA methylation variants. In CG/CHG contexts, the same genomic regions were often affected by multiple stresses, suggesting a generic methylome response. Moreover, these variants showed striking overlap with naturally occurring methylation variants between trees from different locations. Drought treatment triggered CHH hypermethylation of transposable elements, affecting entire superfamilies near drought-responsive genes. Thus, we revealed genomic hotspots of methylation change that are not stress-specific and that contribute to natural DNA methylation variation, and identified stress-specific hypermethylation of entire transposon superfamilies with possible functional consequences. Our results underscore the importance of studying multiple stressors in a single experiment for recognizing general versus stress-specific methylome responses. [ABSTRACT FROM AUTHOR]

Korean landrace red peppers (Capsicum annuum var. Subicho), such as the traditional representative Subicho variety, are integral to Korean foods and are often consumed raw or used as a dried powder for cuisine. However, the known vulnerability of local varieties of landrace to biotic stresses can compromise their quality and yield. We employed nuclear magnetic resonance (NMR) spectroscopy coupled with a multivariate analysis to uncover and compare the metabolomic profiles of healthy and biotic-stressed Subicho peppers. We identified 42 metabolites, with significant differences between the groups. The biotic-stressed Subicho red peppers exhibited lower sucrose levels but heightened concentrations of amino acids, particularly branched-chain amino acids (valine, leucine, and isoleucine), suggesting a robust stress resistance mechanism. The biotic-stressed red peppers had increased levels of TCA cycle intermediates (acetic, citric, and succinic acids), nitrogen metabolism-related compounds (alanine, asparagine, and aspartic acid), aromatic amino acids (tyrosine, phenylalanine, and tryptophan), and γ-aminobutyric acid. These findings reveal the unique metabolic adaptations of the Subicho variety, underscoring its potential resilience to biotic stresses. This novel insight into the stress response of the traditional Subicho pepper can inform strategies for developing targeted breeding programs and enhancing the quality and economic returns in the pepper and food industries. [ABSTRACT FROM AUTHOR]

Summary: Viroids are pathogenic noncoding RNAs that completely rely on their host molecular machinery to accomplish their life cycle. Several interactions between viroids and their host molecular machinery have been identified, including interference with epigenetic mechanisms such as DNA methylation. Despite this, whether viroids influence changes in other epigenetic marks such as histone modifications remained unknown. Epigenetic regulation is particularly important during pathogenesis processes because it might be a key regulator of the dynamism of the defense response.Here we have analyzed the changes taking place in Cucumis sativus (cucumber) facultative and constitutive heterochromatin during hop stunt viroid (HSVd) infection using chromatin immunoprecipitation (ChIP) of the two main heterochromatic marks: H3K9me2 and H3K27me3.We find that HSVd infection is associated with changes in both H3K27me3 and H3K9me2, with a tendency to decrease the levels of repressive epigenetic marks through infection progression. These epigenetic changes are connected to the transcriptional regulation of their expected targets, genes, and transposable elements. Indeed, several genes related to the defense response are targets of both epigenetic marks.Our results highlight another host regulatory mechanism affected by viroid infection, providing further information about the complexity of the multiple layers of interactions between pathogens/viroids and hosts/plants. [ABSTRACT FROM AUTHOR]

Biotic and abiotic environmental cues are major factors influencing plant growth and productivity. Interactions with biotic (e.g. symbionts and pathogens) and abiotic (e.g. changes in temperature, water, or nutrient availability) factors trigger signaling and downstream transcriptome adjustments in plants. While bulk RNA-sequencing technologies have traditionally been used to profile these transcriptional changes, tissue homogenization may mask heterogeneity of responses resulting from the cellular complexity of organs. Thus, whether different cell types respond equally to environmental fluctuations, or whether subsets of the responses are cell-type specific, are long-lasting questions in plant biology. The recent breakthrough of single-cell transcriptomics in plant research offers an unprecedented view of cellular responses under changing environmental conditions. In this review, we discuss the contribution of single-cell transcriptomics to the understanding of cell-type-specific plant responses to biotic and abiotic environmental interactions. Besides major biological findings, we present some technical challenges coupled to single-cell studies of plant–environment interactions, proposing possible solutions and exciting paths for future research. [ABSTRACT FROM AUTHOR]

The Nascent polypeptide‐Associated Complex (NAC) family is among the largest plant‐specific TF families and plays an important role in plant growth, development, and stress responses. NAC TFs have been extensively studied in plants such as rice and Arabidopsis; however, their characterization, functions, evolution, and expression patterns in Manihot esculenta (cassava) under environmental stress remain largely unexplored. Here, we used bioinformatic analyses and biotic stress responses to investigate the physicochemical properties, chromosome location, phylogeny, gene structure, expression patterns, and cis‐elements in promoter regions of the NAC TFs in cassava. We identified 119 M. esculenta NAC (MeNAC) gene families, unevenly distributed on 16 chromosomes. We investigated expression patterns of all identified MeNAC TFs under Xanthomonas axonopodis pv. manihotis (Xam) infection, strain CHN11, at different time points. Only 20 MeNAC TFs showed expression of significant bacterial resistance. Six MeNACs (MeNAC7, 26, 63, 65, 77, and 113) were selected for functional analysis. qRT‐PCR assays revealed that MeNAC7, 26, 63, 65, 77, and 113 were induced in response to XamCHN11 infection and may participate in the molecular interaction of cassava and bacterial blight. Interestingly, MeNAC26, MeNAC63, MeNAC65, and MeNAC113 responded to XamCHN11 infection at 3 h post‐inoculation. Furthermore, we identified 13 stress‐related cis‐elements in promoter regions of the MeNAC genes that are involved in diverse environmental stress responses. Phylogenetic analysis revealed that MeNAC genes with similar structures and motif distributions were grouped. This study provides valuable insights into the evolution, diversity, and characterization of MeNAC TFs. It lays the groundwork for a better understanding of their biological roles and molecular mechanisms in cassava. [ABSTRACT FROM AUTHOR]

Background: Alfalfa (Medicago sativa L.) is an essential leguminous forage with high nutrition and strong adaptability. The TIFY family is a plant-specific transcription factor identified in many plants. However, few reports have been reported on the phylogenetic analysis and gene expression profiling of TIFY family genes in alfalfa. Result: A total of 84 TIFY genes belonging to 4 categories were identified in alfalfa, including 58 MsJAZs, 18 MsZMLs, 4 MsTIFYs and 4 MsPPDs, respectively. qRT-PCR data from 8 genes in different tissues revealed that most MsTIFY genes were highly expressed in roots. The expression of MsTIFY14 was up-regulated after different times in both thrips-resistant and susceptible alfalfa after thrips feeding, and the expression of the remaining MsTIFYs had a strong correlation with the time of thrips feeding. Different abiotic stresses, including drought, salt, and cold, could induce or inhibit the expression of MsTIFY genes to varying degrees. In addition, the eight genes were all significantly up-regulated by JA and/or SA. Interestingly, MsTIFY77 was induced considerably by all the biotic, abiotic, or plant hormones (JA or SA) except ABA. Conclusion: Our study identified members of the TIFY gene family in alfalfa and analyzed their structures and possible functions. It laid the foundation for further research on the molecular functions of TIFYs in alfalfa. [ABSTRACT FROM AUTHOR]

The MD-2-related lipid-recognition (ML/Md-2) domain is a lipid/sterol-binding domain that are involved in sterol transfer and innate immunity in eukaryotes. Here we report a genome-wide survey of this family, identifying 84 genes in 30 fungi including plant pathogens. All the studied species were found to have varied ML numbers, and expansion of the family was observed in Rhizophagus irregularis (RI) with 33 genes. The molecular docking studies of these proteins with cholesterol derivatives indicate lipid-binding functional conservation across the animal and fungi kingdom. The phylogenetic studies among eukaryotic ML proteins showed that Puccinia ML members are more closely associated with animal (insect) npc2 proteins than other fungal ML members. One of the candidates from leaf rust fungus Puccinia triticina, Pt5643 was PCR amplified and further characterized using various studies such as qRT-PCR, subcellular localization studies, yeast functional complementation, signal peptide validation, and expression studies. The Pt5643 exhibits the highest expression on the 5th day post-infection (dpi). The confocal microscopy of Pt5643 in onion epidermal cells and N. benthamiana shows its location in the cytoplasm and nucleus. The functional complementation studies of Pt5643 in npc2 mutant yeast showed its functional similarity to the eukaryotic/yeast npc2 gene. Furthermore, the overexpression of Pt5643 also suppressed the BAX, NEP1, and H₂O₂-induced program cell death in Nicotiana species and yeast. Altogether the present study reports the novel function of ML domain proteins in plant fungal pathogens and their possible role as effector molecules in host defense manipulation. [ABSTRACT FROM AUTHOR]

Plants are rich in tandem repeats-containing proteins. It is postulated that the occurrence of tandem repeat gene families facilitates the adaptation and survival of plants in adverse environmental conditions. This study intended to identify the tandem repeats in the transcriptome of a high potential tropical horticultural plant, roselle (Hibiscus sabdariffa L.). A total of 92,974 annotated de novo assembled transcripts were analysed using in silico approach, and 6,541 transcripts that encoded proteins containing tandem repeats with length of 20-60 amino acid residues were identified. Domain analysis revealed a total of nine tandem repeat protein families in the transcriptome of roselle, which are the Ankyrin repeats (ANK), Armadillo repeats (ARM), elongation factor-hand domain repeats (EF- hand), Huntingtin, elongation factor 3, protein phosphatase 2A, yeast kinase TOR1 repeats (HEAT), Kelch repeats (Kelch), leucine rich repeats (LRR), pentatricopeptide repeats (PPR), tetratricopeptide repeats (TPR) and WD40 repeats (WD40). Functional annotation analysis further matched 6,236 transcripts to 1,045 known proteins that contained tandem repeats including proteins implicated in plant development, protein-protein interaction, immunity and abiotic stress responses. The findings provide new insights into the occurrence of tandem repeats in the transcriptome and lay the foundation to elucidate the functional associations between tandem peptide repeats (TRs) and proteins in roselle and facilitate the identification of novel biotic and abiotic response related tandem repeats genes that may be useful in breeding improved varieties. [ABSTRACT FROM AUTHOR]

Legumes have played an essential part as food and feed, but their productivity is inadequate to deliver the protein needs of a rapidly growing human population and livestock sectors. In numerous places around the world, legumes are the peculiar source of protein which essential for the human consumption. They are typically used as a supplement to other dietary proteins. As legumes have the richest protein source, the health experts and consumers demand increased rapidly. Simultaneously, the inhabitants of humans in the universe increased promptly. Meanwhile, fluctuation in biotic and also abiotic components is an extensive constraint for crop growth. It may provoke stress which results in the reduction of yield. However, the legume shows recalcitrant nature, these are the major root cause of the shortage of food. The biotechnology provides a solution to rectify all those issues and genetic transformation plays a consequential impact on enhancement of the legume productivity. This review clearly emphasizes the constraints of legume productivity, the strategy used, skill requirement and current advances in biotechnology for legume improvement. [ABSTRACT FROM AUTHOR]

The impact of climate change on plant growth and productivity is profound, resulting in significant stresses such as biotic and abiotic factors. Among the abiotic stresses, temperature extremes, nutrient imbalances, heavy metals, drought, and salinity stand out as prominent contributors to substantial crop yield losses globally, exacerbating food insecurity concerns. Various methods are currently being explored to enhance plants' resilience to these stresses. We undertook an extensive literature review to assess the current landscape of knowledge in Nano biotechnology and identify areas where existing research is deficient or underexplored. This examination focused on identifying gaps related to methodology, scope, applications, and specific challenges within nanobiotechnology. We also evaluated recent developments and emerging trends in the field, identifying areas where research interest is expanding but remains relatively uncharted. By narrowing our research scope, we aimed to pinpoint specific aspects of Nano biotechnology requiring further investigation or that have not been sufficiently addressed. One promising approach involves the use of nanoparticles, which have shown to positively influence plant performance under stressful conditions. Nanoparticles facilitate nutrient uptake by plants, combat plant diseases and pathogens, and enable the detection and monitoring of trace components in soil through signal absorption. Understanding the mechanisms by which nanoparticles assist plants in mitigating abiotic challenges holds great promise for developing enduring solutions. However, urgent action is needed to implement rapid strategies that alleviate abiotic stress and enhance agricultural productivity. [ABSTRACT FROM AUTHOR]

The population growth and the regular breakout of Nilaparvata lugens pose a significant risk to rice cultivation. Four different N. lugens biotypes have been identified worldwide, with biotype 4 being the most destructive and prevalent throughout Asia, particularly in India. Therefore, a rice variety with multiple resistance genes/alleles is required for effective management of N. lugens. Hence, 191 rice genotypes collected from various parts of India were evaluated for resistance to N. lugens. Further, SSR markers representing 23 different N. lugens resistant (R) genes were assayed to identify genomic regions associated with resistance. The results of the genetic analysis showed that the average genetic diversity value of all markers was 0.165 and polymorphic information content of 0.145 for all the markers used. The population structure and cluster analysis divided the studied genotypes into three distinct groups, with resistant genotypes grouped separately. These findings were confirmed by the principal coordinate analysis, which categorized resistant genotypes, moderately resistant genotypes, and susceptible genotypes into distinct components. Additionally, 90% of the genetic variation was between individuals of populations and 10% between the populations. Marker‐trait association study through mixed linear model and generalized linear model identified six SSR markers such as RM6732 (Bph15), RM314 (Bph6), RM16999 (Bph6), RM7 (QBph3), RM401 (bph4), and RM7102 (Bph1), which were significantly associated with various phenotypic parameters, such as feeding mark, honeydew excretion, percent damage and nymphal survival. The resistant genes identified in these genotypes could help in the marker‐assisted rice variety development with durable resistance against N. lugens. [ABSTRACT FROM AUTHOR]

Rich nutrients, climate resilience, and the economic importance of millets are believed to ensure food security for future generations. Millets have the habit of growing against abiotic stresses (particularly drought stress). Millets show much better climate resilience and nutrient supplementation properties compared to other major cereals. Understanding the molecular mechanisms of genes that respond to stresses and nutrient transport will help understand the tolerance mechanism and improve against both stresses. Genome sequences are currently available for two major (sorghum and pearl millet) and eight minor millets (foxtail millet, finger millet, kodo millet, barnyard millet, proso millet, job's tear, fonio millet, and tef). Five minor millets (little millet, kodo millet, brown top millet, guinea millet, and raishan) do not have genome sequences to date. Transcriptome studies help to identify differentially expressed genes (DEGs), mine genes induced in a particular stress and develop several molecular markers for all plants, including millets. Some millets have reports on transcriptome datasets for plants exposed to various biotic and abiotic stresses and for nutritional traits. Unfortunately, the transcriptome datasets of millets have not been adequately leveraged to explore genes associated with traits such as climate resilience, nutrient enrichment, and crop improvement. This underutilization stems from a lack of high-resolution studies and limited exploration within the field. As a result, the potential insights and genetic understanding offered by these datasets remain largely untapped. Through this review, we plan to elucidate the current status of transcriptome resources on millets and draw future insights on the utilization of these resources. This review will motivate researchers to utilize the available transcriptome resources for millet improvement. [ABSTRACT FROM AUTHOR]

This review summarizes recent progress in our current understanding of the mechanisms underlying the cell death pathways in bryophytes, focusing on conserved pathways and particularities in comparison to angiosperms. Regulated cell death (RCD) plays key roles during essential processes along the plant life cycle. It is part of specific developmental programmes and maintains homeostasis of the organism in response to unfavourable environments. Bryophytes could provide valuable models to study developmental RCD processes as well as those triggered by biotic and abiotic stresses. Some pathways analogous to those present in angiosperms occur in the gametophytic haploid generation of bryophytes, allowing direct genetic studies. In this review, we focus on such RCD programmes, identifying core conserved mechanisms and raising new key questions to analyse RCD from an evolutionary perspective. [ABSTRACT FROM AUTHOR]

Environmental stress affects food productivity by producing reactive oxygen species (ROS) that damage cell organelles and biomolecules, leading to apoptosis. Plants have developed a variety of defense responses over time to counteract the detrimental effects of biotic and abiotic stresses. However, in order to combat climate change and the deterioration of ecosystems, it will be necessary to promote the use of beneficial bacteria including plant growth-promoting bacteria (PGPR) in agricultural ecosystems. PGPR potentially improves nutrient absorption, modulates hormone levels, and/or improves tolerance to abiotic stress factors and plant pathogens. PGPR offers a sustainable replacement for conventional agrochemicals and traditional farming practices by improving plant growth and stress tolerance. In this context, studying the fundamental evolutionary and ecological relationships among plants and their microbiomes is necessary to build vital approaches to strengthen traditional agricultural techniques. Stress-tolerant PGPR can release bioactive substances such as gibberellins and indole acetic acid which participate in mitigating stresses. PGPR could minimize the adverse effect of salinity, drought, heavy metals, floods, and other stresses on plants by inducing antioxidant enzymes, like catalase, peroxidase, and superoxide dismutase. This review summarizes the current developments in the PGPR-based strategy for tackling biotic and abiotic stresses. [ABSTRACT FROM AUTHOR]

Elicitation, the process of stimulating plants to enhance the production of valuable secondary metabolites, has emerged as a significant avenue in the field of plant biotechnology. This review paper provides a comprehensive examination of elicitation, encompassing its mechanisms, the imperative for its utilization, and the diverse array of elicitors employed, including abiotic, biotic, and nanoparticle-based agents. By exploring the intricate signaling pathways and molecular responses triggered by external stimuli in this review, we gain insights into how plants tailor their metabolite production in reaction to their environment. Intricately intertwined with the mechanisms, the types of elicitors utilized are extensively discussed. Abiotic elicitors, encompassing physical factors and chemicals, biotic elicitors involving microbe-derived molecules, plant hormones and symbiotic microorganisms, and the emerging application of nanoparticles as elicitation agents are explored. The review further examines the application of these elicitors in both in-vitro and in-vivo cultures, showcasing their practical utility in controlled laboratory settings and real-world environments. By assessing the efficacy of diverse elicitors, this paper provides valuable insights into tailoring elicitation strategies to enhance secondary metabolite yields for various applications. Addressing the limitations and leveraging emerging technologies will undoubtedly steer elicitation research towards innovative breakthroughs, further enhancing our capacity to harness plants for sustainable and efficient secondary metabolite production. [ABSTRACT FROM AUTHOR]

The Fall armyworm (FAW), Spodoptera frugiperda (J. E. Smith), is a highly destructive lepidopteran pest known for its extensive feeding on maize (Zea mays L.) and other crops, resulting in a substantial reduction in crop yields. Understanding the metabolic response of maize to FAW infestation is essential for effective pest management and crop protection. Metabolomics, a powerful analytical tool, provides insights into the dynamic changes in maize's metabolic profile in response to FAW infestation. This review synthesizes recent advancements in metabolomics research focused on elucidating maize's metabolic responses to FAW and other lepidopteran pests. It discusses the methodologies used in metabolomics studies and highlights significant findings related to the identification of specific metabolites involved in FAW defense mechanisms. Additionally, it explores the roles of various metabolites, including phytohormones, secondary metabolites, and signaling molecules, in mediating plant–FAW interactions. The review also examines potential applications of metabolomics data in developing innovative strategies for integrated pest management and breeding maize cultivars resistant to FAW by identifying key metabolites and associated metabolic pathways involved in plant–FAW interactions. To ensure global food security and maximize the potential of using metabolomics in enhancing maize resistance to FAW infestation, further research integrating metabolomics with other omics techniques and field studies is necessary. [ABSTRACT FROM AUTHOR]

Eucalyptus are trees sensitive to interference imposed by weeds mainly during the early growth phase. The repetitive use of herbicides with the same mechanism of action has led to the selection of resistant weeds, and Digitaria insularis stands out for its resistance to glyphosate. Due to its occurrence in eucalyptus plantations, knowledge regarding D. insularis interference in eucalyptus early growth is needed to develop management strategies. This study aimed to confirm D. insularis glyphosate-resistence; and also to evaluate the effect of densities and distances of glyphosate-resistant D. insularis, seeded and in regrowth, on the early growth of Eucalyptus urophylla × E. grandis (Clone AEC-144). Prior to eucalyptus' experiments, D. insularis glyphosate-resistance was confirmed through a dose–response curve experiment. After that, two experiments [one for weed's first growth (seeded) and other for second growth (regrowth)] were carried out in an open area, in 700 L pots, for 105 days after planting eucalyptus seedlings. The treatments consisted of increasing densities of D. insularis (0, 1, 2 and 3 plants m−2) planted at 10, 20 or 30 cm from the eucalyptus seedlings. Eucalyptus height, stem diameter, leaf area and dry matter were evaluated. The eucalyptus variables most sensitive to interference were leaf and stem dry matter, with reductions of 45% and 88.4%, respectively for weeds seeded and regrowth. Weed second growth (regrowth) interfered more aggressively in eucalyptus growth. The coexistence with D. insularis, regardless of density and distance, negatively interfered early tree growth. [ABSTRACT FROM AUTHOR]

The objective of this systematic review (SR) was to select studies on the use of gene editing by CRISPR technology related to plant resistance to biotic stresses. We sought to evaluate articles deposited in six electronic databases, using pre-defined inclusion and exclusion criteria. This SR demonstrates that countries such as China and the United States of America stand out in studies with CRISPR/Cas. Among the most studied crops are rice, tomatoes and the model plant Arabidopsis thaliana. The most cited biotic agents include the genera, Xanthomonas, Manaporthe, Pseudomonas and Phytophthora. This SR also identifies several CRISPR/Cas-edited genes and demonstrates that plant responses to stressors are mediated by many complex signaling pathways. The Cas9 enzyme is used in most articles and Cas12 and 13 are used as additional editing tools. Furthermore, the quality of the articles included in this SR was validated by a risk of bias analysis. The information collected in this SR helps to understand the state of the art of CRISPR/Cas aimed at improving resistance to diseases and pests to understand the mechanisms involved in most host–pathogen relationships. This SR shows that the CRISPR/Cas system provides a straightforward method for rapid gene targeting, providing useful information for plant breeding programs.

Transcription factors (TFs) regulate gene expression by binding to DNA. The NAC gene family in plants consists of crucial TFs that influence plant development and stress responses. The whole genome of Capsicum annuum shows over 100 NAC genes (CaNAC). Functional characteristics of the most CaNAC TFs are unknown. In this study, we identified CaNAC4, a novel NAC TF in C. annuum. CaNAC4 expression increased after inoculation with the pathogens, Xanthomonas axonopodis pv. vesicatoria race 3 and X. axonopodis pv. glycines 8ra, and following treatment with the plant hormones, salicylic acid and abscisic acid. We investigated the functional characteristics of the CaNAC4 gene and its roles in salt tolerance and anti-pathogen defense in transgenic Nicotiana benthamiana. For salt stress analysis, the leaf discs of wild-type and CaNAC4-transgenic N. benthamiana plants were exposed to different concentrations of sodium chloride. Chlorophyll loss was more severe in salt stress-treated wild-type plants than in CaNAC4-transgenic plants. To analyze the role of CaNAC4 in anti-pathogen defense, a spore suspension of Botrytis cinerea was used to infect the leaves. The disease caused by B. cinerea gradually increased in severity, and the symptoms were clearer in the CaNAC4-transgenic lines. We also investigated hypersensitive response (HR) in CaNAC4-transgenic plants. The results showed a stronger HR in wild-type plants after infiltration with the apoptosis regulator, BAX. In conclusion, our results suggest that CaNAC4 may enhance salt tolerance and act as a negative regulator of biotic stress in plants.

Abiotic and biotic stressors adversely affect plant survival, biomass generation, and crop yields. As the global availability of arable land declines and the impacts of global warming intensify, such stressors may have increasingly pronounced effects on agricultural productivity. Currently, researchers face the overarching challenge of comprehensively enhancing plant resilience to abiotic and biotic stressors. The secondary cell wall plays a crucial role in bolstering the stress resistance of plants. To increase plant resistance to stress through genetic manipulation of the secondary cell wall, we cloned a cell wall protein designated glycine-rich protein-like (GhGRPL) from cotton fibers, and found that it is specifically expressed during the period of secondary cell wall biosynthesis. Notably, this protein differs from its Arabidopsis homolog, AtGRP, since its glycine-rich domain is deficient in glycine residues. GhGRPL is involved in secondary cell wall deposition. Upregulation of GhGRPL enhances lignin accumulation and, consequently, the thickness of the secondary cell walls, thereby increasing the plant's resistance to abiotic stressors, such as drought and salinity, and biotic threats, including Verticillium dahliae infection. Conversely, interference with GhGRPL expression in cotton reduces lignin accumulation and compromises that resistance. Taken together, our findings elucidate the role of GhGRPL in regulating secondary cell wall development through its influence on lignin deposition, which, in turn, reinforces cell wall robustness and impermeability. These findings highlight the promising near-future prospect of adopting GhGRPL as a viable, effective approach for enhancing plant resilience to abiotic and biotic stress factors.

Abstract Background Alfalfa (Medicago sativa L.) is an essential leguminous forage with high nutrition and strong adaptability. The TIFY family is a plant-specific transcription factor identified in many plants. However, few reports have been reported on the phylogenetic analysis and gene expression profiling of TIFY family genes in alfalfa. Result A total of 84 TIFY genes belonging to 4 categories were identified in alfalfa, including 58 MsJAZs, 18 MsZMLs, 4 MsTIFYs and 4 MsPPDs, respectively. qRT-PCR data from 8 genes in different tissues revealed that most MsTIFY genes were highly expressed in roots. The expression of MsTIFY14 was up-regulated after different times in both thrips-resistant and susceptible alfalfa after thrips feeding, and the expression of the remaining MsTIFYs had a strong correlation with the time of thrips feeding. Different abiotic stresses, including drought, salt, and cold, could induce or inhibit the expression of MsTIFY genes to varying degrees. In addition, the eight genes were all significantly up-regulated by JA and/or SA. Interestingly, MsTIFY77 was induced considerably by all the biotic, abiotic, or plant hormones (JA or SA) except ABA. Conclusion Our study identified members of the TIFY gene family in alfalfa and analyzed their structures and possible functions. It laid the foundation for further research on the molecular functions of TIFYs in alfalfa.

Abstract Background CINNAMYL ALCOHOL DEHYDROGENASE (CAD) catalyzes the NADPH-dependent reduction of cinnamaldehydes into cinnamyl alcohols and is a key enzyme found at the final step of the monolignol pathway. Cinnamyl alcohols and their conjugates are subsequently polymerized in the secondary cell wall to form lignin. CAD genes are typically encoded by multi-gene families and thus traditionally organized into general classifications of functional relevance. Results In silico analysis of the hexaploid Triticum aestivum genome revealed 47 high confidence TaCAD copies, of which three were determined to be the most significant isoforms (class I) considered bone fide CADs. Class I CADs were expressed throughout development both in RNAseq data sets as well as via qRT-PCR analysis. Of the 37 class II TaCADs identified, two groups were observed to be significantly co-expressed with class I TaCADs in developing tissue and under chitin elicitation in RNAseq data sets. These co-expressed class II TaCADs were also found to be phylogenetically unrelated to a separate clade of class II TaCADs previously reported to be an influential resistance factor to pathogenic fungal infection. Lastly, two groups were phylogenetically identified as class III TaCADs, which possess distinct conserved gene structures. However, the lack of data supporting their catalytic activity for cinnamaldehydes and their bereft transcriptional presence in lignifying tissues challenges their designation and function as CADs. Conclusions Taken together, our comprehensive transcriptomic analyses suggest that TaCAD genes contribute to overlapping but nonredundant functions during T. aestivum growth and development across a wide variety of agroecosystems and provide tolerance to various stressors.

Abstract Gray mold of roses, caused by the necrotrophic fungal pathogen Botrytis cinerea, is an economically notorious disease and a well-known economic menace, leading to substantial annual losses estimated at no less than 30% of production. This disease takes a toll not only on the marketability of cut rose flowers but also on consumer and importer confidence due to the unsightly symptoms it induces. This fungus influences the rose foliage throughout cultivation, transportation, storage, and marketing. The interplay of conducive environmental conditions and genetic factors plays significant roles in developing the rose gray mold on rose flowers during the pre- and post-harvest phases. Nevertheless, the molecular mechanisms underlying B. cinerea-rose interactions are poorly understood, and the knowledge of how rose plants defend themselves against B. cinerea infection is not comprehensively investigated. It is worth noting that breeding for resistance to discover genetically resistant roses toward gray mold was unsuccessful despite research conducted over the past century. Consequently, synthetic fungicides remain the primary approach to controlling Botrytis blight in roses during the pre- and post-harvest stages. However, this measure has several drawbacks, including the emergence of fungicide-resistant B. cinerea and endangering human and animal health due to chemical residues in the food chain. This review aims to offer a comprehensive update on recent research findings on the biology and management of B. cinerea infection in roses and to propose novel strategies for managing gray mold disease.

Abstract Gamma-aminobutyric acid (GABA), a ubiquitous non-protein 4-carbon amino acid present in both prokaryotic and eukaryotic organisms. It is conventionally recognized as a neurotransmitter in mammals and plays a crucial role in plants. The context of this review centers on the impact of GABA in mitigating abiotic stresses induced by climate change, such as drought, salinity, heat, and heavy metal exposure. Beyond its neurotransmitter role, GABA emerges as a key player in diverse metabolic processes, safeguarding plants against multifaceted abiotic as well as biotic challenges. This comprehensive exploration delves into the GABA biosynthetic pathway, its transport mechanisms, and its intricate interplay with various abiotic stresses. The discussion extends to the nuanced relationship between GABA and phytohormones during abiotic stress acclimation, offering insights into the strategic development of mitigation strategies against these stresses. The delineation of GABA's crosstalk with phytohormones underscores its pivotal role in formulating crucial strategies for abiotic stress alleviation in plants.

Abstract Background Pests and diseases are a major contributor to yield losses in sub-Saharan Africa, prompting smallholder farmers to seek cost-effective, accessible and ecologically friendly alternatives for crop protection. This study explored the management of pests and diseases affecting crops across eight selected villages in Ehlanzeni District, Mpumalanga Province, South Africa. Methods A total of 120 smallholder farmers were purposefully selected utilising the snowball technique. Information on the management of plant pests and diseases was collected through interviews and focus group discussions using semi-structured interview schedules. Ethnobotanical indices, including relative frequency of citation (RFC), use-value (UV) and informant consensus factor (Fic), were used to quantify and rank the plants used for crop protection in the study area. Results Twenty-three plant species (16 naturalised exotics and seven indigenous plants) belonging to 16 families were used for managing pests (vertebrates and invertebrates) and diseases (fungal and bacterial related) affecting crops in the study area. The dominant (100%) crops cultivated by the participants were Allium cepa L., Mangifera indica L., Solanum lycopersicum L. and Zea mays L. The RFC value ranged from 0.08 to 0.83 and the three most popular plants for crop protection were Capsium annuum L. (0.83), A. cepa (0.63) and Dichrostachys cinerea (L.) Wight & Arn. (0.43). In terms of the UV, the five most promising plants used as biocontrol were Tulbaghia violacea (0.13), A. cepa (0.12), C. annuum L. (0.09), Solanum campylacanthum Hochst. Ex A.Rich.(0.09) and Pinus pinaster (0.08). Based on the Fic, four categories were established and dominated by fungal diseases (0.64). Furthermore, T. violacea and A. cepa were the most often mentioned plants used against fungal conditions. Other categories cited were bacterial diseases (0.3), invertebrate pests (0.11) and vertebrate pests (0.14), an indication that smallholder farmers had limited agreement or common knowledge about the plants used for their management. The preparation methods included maceration (38%), decoction (38%) and burning (24%). Foliar application (67%) and soil drenching (33%) were used for administering plant extracts during the management of crop pests and diseases. Conclusion The study highlights the importance of botanicals and associated indigenous knowledge among smallholder farmers in Mpumalanga Province, South Africa. It is pertinent to explore the valorisation of these botanicals by generating empirical data on their biological efficacies and phytochemical profiles.

Among the many biotic factors with adverse effects on Solanum lycopersicum (tomato), diseases caused by fungi, viruses and nematodes are notable. Since the genome of S. lycopersicum became available, efforts have continued to identify the genes and proteins associated with the plant defence activity. One such gene family belongs to TIR-NBS-LRR (TNL), a subfamily of larger NBS-LRR genes. In total, 27 full-length TNLs were identified via genome wide analysis. Four pairs of segmental duplication events were observed involving different pairs of chromosomes, except the pairing of Solyc02g082050-Solyc02g032650, which were both present on chromosome 2. More than twenty nine percent (29.63%) of the genes were localised on chromosome 1 alone. Hormone-mediated biotic stress-responsive cis-regulatory elements were detected for methyl-jasmonate, salicylic acid (TCA motif) and ethylene (ERE motif). Differential gene expression was observed for many genes under different plant tissues and biotic stresses. The upregulation of many genes including SlBS4 was observed against Alternaria solani attacks in the disease tolerant varieties. Altogether, the results suggested that TNLs play a significant role in plant defence under biotic stress.

Abstract Background The dirigent (DIR) genes encode proteins that act as crucial regulators of plant lignin biosynthesis. In Solanaceae species, members of the DIR gene family are intricately related to plant growth and development, playing a key role in responding to various biotic and abiotic stresses. It will be of great application significance to analyze the DIR gene family and expression profile under various pathogen stresses in Solanaceae species. Results A total of 57 tobacco NtDIRs and 33 potato StDIRs were identified based on their respective genome sequences. Phylogenetic analysis of DIR genes in tobacco, potato, eggplant and Arabidopsis thaliana revealed three distinct subgroups (DIR-a, DIR-b/d and DIR-e). Gene structure and conserved motif analysis showed that a high degree of conservation in both exon/intron organization and protein motifs among tobacco and potato DIR genes, especially within members of the same subfamily. Total 8 pairs of tandem duplication genes (3 pairs in tobacco, 5 pairs in potato) and 13 pairs of segmental duplication genes (6 pairs in tobacco, 7 pairs in potato) were identified based on the analysis of gene duplication events. Cis-regulatory elements of the DIR promoters participated in hormone response, stress responses, circadian control, endosperm expression, and meristem expression. Transcriptomic data analysis under biotic stress revealed diverse response patterns among DIR gene family members to pathogens, indicating their functional divergence. After 96 h post-inoculation with Ralstonia solanacearum L. (Ras), tobacco seedlings exhibited typical symptoms of tobacco bacterial wilt. The qRT-PCR analysis of 11 selected NtDIR genes displayed differential expression pattern in response to the bacterial pathogen Ras infection. Using line 392278 of potato as material, typical symptoms of potato late blight manifested on the seedling leaves under Phytophthora infestans infection. The qRT-PCR analysis of 5 selected StDIR genes showed up-regulation in response to pathogen infection. Notably, three clustered genes (NtDIR2, NtDIR4, StDIR3) exhibited a robust response to pathogen infection, highlighting their essential roles in disease resistance. Conclusion The genome-wide identification, evolutionary analysis, and expression profiling of DIR genes in response to various pathogen infection in tobacco and potato have provided valuable insights into the roles of these genes under various stress conditions. Our results could provide a basis for further functional analysis of the DIR gene family under pathogen infection conditions.

Abstract Background Small-secreted peptides are increasingly recognized as a novel class of intracellular signal molecules, playing crucial roles in plant growth and development. However, the precise role and mechanism governed by peptides containing Tyrosine Sulfation (PSY) are still under investigation. Currently, there is a lack of accessible information concerning the PSY gene family in wheat. Results Therefore, in this investigation, we identified 29 PSY genes in Triticum aestivum, with the aim of unraveling their significance in plant development processes and their response to a variety of stress conditions. Phylogenetic analysis showed that TaPSY genes clustered into five groups. Additionally, an analysis of the gene structure of TaPSYs displayed a conserved evolutionary path. The syntenic relationship demonstrated the 69 orthologous gene pairs in T. dicoccoides, Ae. tauschii, T. turgidum, and H. vulgare, respectively. Furthermore, the Ka/Ks analysis indicated that TaPSY genes have experienced purifying selection during their evolutionary processes. The promoters of TaPSY genes were found to contain numerous CAREs, and these elements are known to perform essential functions in various development processes, phytohormone responses, as well as defense and stress mechanisms. In addition, the identification of potential miRNAs targeting TaPSY genes was followed by an examination of their expression patterns across various tissues. Among the 29 TaPSY genes, twenty miRNAs were discovered to target eighteen of them. Moreover, TaPSY genes displayed a distinct expression across different tissues and stress conditions. Conclusions Hence, these discoveries offer a significant reference point for forthcoming molecular investigations and hold promise for bolstering wheat yield and stress resilience through targeted genetic enhancements and strategic breeding approaches. Graphical Abstract

Background: CINNAMYL ALCOHOL DEHYDROGENASE (CAD) catalyzes the NADPH-dependent reduction of cinnamaldehydes into cinnamyl alcohols and is a key enzyme found at the final step of the monolignol pathway. Cinnamyl alcohols and their conjugates are subsequently polymerized in the secondary cell wall to form lignin. CAD genes are typically encoded by multi-gene families and thus traditionally organized into general classifications of functional relevance. Results: In silico analysis of the hexaploid Triticum aestivum genome revealed 47 high confidence TaCAD copies, of which three were determined to be the most significant isoforms (class I) considered bone fide CADs. Class I CADs were expressed throughout development both in RNAseq data sets as well as via qRT-PCR analysis. Of the 37 class II TaCADs identified, two groups were observed to be significantly co-expressed with class I TaCADs in developing tissue and under chitin elicitation in RNAseq data sets. These co-expressed class II TaCADs were also found to be phylogenetically unrelated to a separate clade of class II TaCADs previously reported to be an influential resistance factor to pathogenic fungal infection. Lastly, two groups were phylogenetically identified as class III TaCADs, which possess distinct conserved gene structures. However, the lack of data supporting their catalytic activity for cinnamaldehydes and their bereft transcriptional presence in lignifying tissues challenges their designation and function as CADs. Conclusions: Taken together, our comprehensive transcriptomic analyses suggest that TaCAD genes contribute to overlapping but nonredundant functions during T. aestivum growth and development across a wide variety of agroecosystems and provide tolerance to various stressors. [ABSTRACT FROM AUTHOR]

Gray mold of roses, caused by the necrotrophic fungal pathogen Botrytis cinerea, is an economically notorious disease and a well-known economic menace, leading to substantial annual losses estimated at no less than 30% of production. This disease takes a toll not only on the marketability of cut rose flowers but also on consumer and importer confidence due to the unsightly symptoms it induces. This fungus influences the rose foliage throughout cultivation, transportation, storage, and marketing. The interplay of conducive environmental conditions and genetic factors plays significant roles in developing the rose gray mold on rose flowers during the pre- and post-harvest phases. Nevertheless, the molecular mechanisms underlying B. cinerea-rose interactions are poorly understood, and the knowledge of how rose plants defend themselves against B. cinerea infection is not comprehensively investigated. It is worth noting that breeding for resistance to discover genetically resistant roses toward gray mold was unsuccessful despite research conducted over the past century. Consequently, synthetic fungicides remain the primary approach to controlling Botrytis blight in roses during the pre- and post-harvest stages. However, this measure has several drawbacks, including the emergence of fungicide-resistant B. cinerea and endangering human and animal health due to chemical residues in the food chain. This review aims to offer a comprehensive update on recent research findings on the biology and management of B. cinerea infection in roses and to propose novel strategies for managing gray mold disease. [ABSTRACT FROM AUTHOR]

Lipids are organic nonpolar molecules with essential biological and economic importance. While the genetic pathways and regulatory networks of lipid biosynthesis and metabolism have been extensively studied and thoroughly reviewed in oil crops such as soybeans, less attention has been paid to the biological roles of lipids in rice, a staple food for the global population and a model species for plant molecular biology research, leaving a considerable knowledge gap in the biological roles of lipids. In this review, we endeavor to furnish a current overview of the advancements in understanding the genetic foundations and physiological functions of lipids, including triacylglycerol, fatty acids, and very-long-chain fatty acids. We aim to summarize the key genes in lipid biosynthesis, metabolism, and transcriptional regulation underpinning rice's developmental and growth processes, biotic stress responses, abiotic stress responses, fertility, seed longevity, and recent efforts in rice oil genetic improvement. [ABSTRACT FROM AUTHOR]

Gamma-aminobutyric acid (GABA), a ubiquitous non-protein 4-carbon amino acid present in both prokaryotic and eukaryotic organisms. It is conventionally recognized as a neurotransmitter in mammals and plays a crucial role in plants. The context of this review centers on the impact of GABA in mitigating abiotic stresses induced by climate change, such as drought, salinity, heat, and heavy metal exposure. Beyond its neurotransmitter role, GABA emerges as a key player in diverse metabolic processes, safeguarding plants against multifaceted abiotic as well as biotic challenges. This comprehensive exploration delves into the GABA biosynthetic pathway, its transport mechanisms, and its intricate interplay with various abiotic stresses. The discussion extends to the nuanced relationship between GABA and phytohormones during abiotic stress acclimation, offering insights into the strategic development of mitigation strategies against these stresses. The delineation of GABA's crosstalk with phytohormones underscores its pivotal role in formulating crucial strategies for abiotic stress alleviation in plants. [ABSTRACT FROM AUTHOR]

Tomato (Solanum lycopersicon L.) is one of the most widely consumed and produced vegetable crops worldwide. It offers numerous health benefits due to its rich content of many therapeutic elements such as vitamins, carotenoids, and phenolic compounds. Biotic stressors such as bacteria, viruses, fungi, nematodes, and insects cause severe yield losses as well as decreasing fruit quality. Conventional breeding strategies have succeeded in developing resistant genotypes, but these approaches require significant time and effort. The advent of state-of-the-art genome editing technologies, particularly CRISPR/Cas9, provides a rapid and straightforward method for developing high-quality biotic stress-resistant tomato lines. The advantage of genome editing over other approaches is the ability to make precise, minute adjustments without leaving foreign DNA inside the transformed plant. The tomato genome has been precisely modified via CRISPR/Cas9 to induce resistance genes or knock out susceptibility genes, resulting in lines resistant to common bacterial, fungal, and viral diseases. This review provides the recent advances and application of CRISPR/Cas9 in developing tomato lines with resistance to biotic stress. [ABSTRACT FROM AUTHOR]

Plants continuously monitor the environment to detect changing conditions and to properly respond, avoiding deleterious effects on their fitness and survival. An enormous number of cell surface and intracellular immune receptors are deployed to perceive danger signals associated with microbial infections. Ligand binding by cognate receptors represents the first essential event in triggering plant immunity and determining the outcome of the tissue invasion attempt. Reactive oxygen and nitrogen species (ROS/RNS) are secondary messengers rapidly produced in different subcellular localizations upon the perception of immunogenic signals. Danger signal transduction inside the plant cells involves cytoskeletal rearrangements as well as several organelles and interactions between them to activate key immune signaling modules. Such immune processes depend on ROS and RNS accumulation, highlighting their role as key regulators in the execution of the immune cellular program. In fact, ROS and RNS are synergic and interdependent intracellular signals required for decoding danger signals and for the modulation of defense-related responses. Here we summarize current knowledge on ROS/RNS production, compartmentalization, and signaling in plant cells that have perceived immunogenic danger signals. [ABSTRACT FROM AUTHOR]

The E3 enzyme in the UPS pathway is a crucial factor for inhibiting substrate specificity. In Solanaceae, the U-box E3 ubiquitin ligase has a complex relationship with plant growth and development, and plays a pivotal role in responding to various biotic and abiotic stresses. The analysis of the U-box gene family in Solanaceae and its expression profile under different stresses holds significant implications. A total of 116 tobacco NtU-boxs and 56 eggplant SmU-boxs were identified based on their respective genome sequences. Phylogenetic analysis of U-box genes in tobacco, eggplant, tomato, Arabidopsis, pepper, and potato revealed five distinct subgroups (IV). Gene structure and protein motifs analysis found a high degree of conservation in both exon/intron organization and protein motifs among tobacco and eggplant U-box genes especially the members within the same subfamily. A total of 15 pairs of segmental duplication and 1 gene pair of tandem duplication were identified in tobacco based on the analysis of gene duplication events, while 10 pairs of segmental duplication in eggplant. It is speculated that segmental duplication events are the primary driver for the expansion of the U-box gene family in both tobacco and eggplant. The promoters of NtU-box and SmU-box genes contained cis-regulatory elements associated with cellular development, phytohormones, environment stress, and photoresponsive elements. Transcriptomic data analysis shows that the expression levels of the tobacco and eggplant U-box genes in different tissues and various abiotic stress conditions. Using cultivar Hongda of tobacco and cultivar Yanzhi of eggplant as materials, qRT-PCR analysis has revealed that 15 selected NtU-box genes and 8 SmU-box may play important roles in response to pathogen Ras invasion both in tobacco and eggplant. [ABSTRACT FROM AUTHOR]

The synthesis, metabolism and transport of plant carbohydrates in different tissues and organs of "source-sink-flow" are essential for the normal life activities of organism. Among them, the short-distance or long-distance transport of sugars, such as sucrose, glucose and fructose, play a key role in the "flow" from source to sink, the transport and distribution of carbohydrates require the synergistic involvement of multiple cellular sugar transporters. Sugars will eventually be exported transporters（SWEETs） exhibit diverse functions, participating in regulating important physiological processes such as nutrient allocation, utilization, tissue organ growth, and development, as well as responding to biotic and abiotic stress by maintaining or regulating cellular sugar levels. This review summarizes the research progress in the basic structural characteristics, physiological functions, and stress responses of the SWEETs gene family, which holds significant implications for understanding plant cellular physiology and research areas like biotic breeding. [ABSTRACT FROM AUTHOR]

Plant development and crop productivity are drastically reduced worldwide due to biotic and abiotic stresses and their unexpected combinations. The various chemicals (pesticides, fertilizers, and phyto-regulators) and genetic engineering techniques employed to date to improve crop tolerance to multiple stresses have a negative influence on the environment and are time-consuming. This has accelerated efforts to find more eco-friendly ways to control plant stress. Chitosan is a biopolymer which is largely extracted from the deacetylation of chitin and appears as a viable tool to overcome these problems in search of a more environmentally acceptable solution. Due to its biocompatibility, eco-friendly and economic nature, become one of the most popular biopolymers used in agriculture. Chitosan also activates a defence mechanism by signal transduction pathway and transduces secondary molecules of hydrogen peroxide and nitric oxide to scavenge reactive oxygen species. Application of chitosan before subjecting to abiotic stresses such as drought, salt, and heat has been shown to stimulate plant growth and enhance the production of antioxidant enzymes, secondary metabolites, and abscisic acid. In drought, it helps to accumulate osmo-protectants to maintain the water potential of plant cells. On the other hand, plant responses towards chitosan are varying based on its structures, doses, developmental stages and crop type. Keeping these facts in mind this review has written with the objective to update the recent studies on chitosan, its various sources and its effective concentrations in different crops, mechanism of action against biotic and abiotic stress management to improve crop production in agriculture. [ABSTRACT FROM AUTHOR]

Key message: Plants respond to environmental challenges by producing reactive species such as ROS and RNS, which play critical roles in signaling pathways that lead to adaptation and survival strategies. Understanding these pathways, as well as their detection methods and effects on plant development and metabolism, provides insight into increasing crop tolerance to combined stresses. Plants encounter various environmental stresses (abiotic and biotic) that affect plant growth and development. Plants sense biotic and abiotic stresses by producing different molecules, including reactive species, that act as signaling molecules and stimulate secondary messengers and subsequent gene transcription. Reactive oxygen and nitrogen species (ROS and RNS) are produced in both physiological and pathological conditions in the plasma membranes, chloroplasts, mitochondria, and endoplasmic reticulum. Various techniques, including spectroscopy, chromatography, and fluorescence methods, are used to detect highly reactive, short-half-life ROS and RNS either directly or indirectly. In this review, we highlight the roles of ROS and RNS in seed germination, root development, senescence, mineral nutrition, and post-harvest control. In addition, we provide information on the specialized metabolism involved in plant growth and development. Secondary metabolites, including alkaloids, flavonoids, and terpenoids, are produced in low concentrations in plants for signaling and metabolism. Strategies for improving crop performance under combined drought and pathogen stress conditions are discussed in this review. [ABSTRACT FROM AUTHOR]