Stress Signaling In Plants Research Articles

Genomic Insights into Disease Resistance in Sunflower (Helianthus annuus): Identifying Key Regions and Candidate Genes for Verticillium dahliae Resistance.

Sunflower (Helianthus annuus) is a globally significant field crop, and disease resistance is crucial for ensuring yield stability and crop quality. Verticillium dahliae is a notorious soilborne pathogen that causes Verticillium Wilt (VW) and threatens sunflower production worldwide. In this study, we conducted a comprehensive assessment of sunflower resistance to V. dahliae across 231 sunflower cultivar lines, from the Sunflower Association Mapping (SAM) population. We employed EMMAX and ridge regression best linear unbiased prediction (rrBLUP) and identified 148 quantitative trait loci (QTLs) and 23 putative genes associated with V. dahliae resistance, including receptor like kinases, cell wall modification, transcriptional regulation, plant stress signalling and defense regulation genes. Our enrichment and quantitative real-time PCR validation results highlight the importance of membrane vesicle trafficking in the sunflower immune system for efficient signaling and defense upon activation by V. dahliae. This study also reveals the polygenic architecture of V. dahliae resistance in sunflowers and provides insights for breeding sunflower cultivars resistant to VW. This research contributes to ongoing efforts to enhance crop resilience and reduce yield losses due to VW, ultimately benefiting sunflower growers and the agricultural sector.

SPX family response to low phosphorus stress and the involvement of ZmSPX1 in phosphorus homeostasis in maize.

Phosphorus (P) is a crucial macronutrient for plant growth and development, and low-Pi stress poses a significant limitation to maize production. While the role of the SPX domain in encoding proteins involved in phosphate (Pi) homeostasis and signaling transduction has been extensively studied in other model plants, the molecular and functional characteristics of the SPX gene family members in maize remain largely unexplored. In this study, we identified six SPX members, and the phylogenetic analysis of ZmSPXs revealed a close relationship with SPX genes in rice. The promoter regions of ZmSPXs were abundant in biotic and abiotic stress-related elements, particularly associated with various hormone signaling pathways, indicating potential intersections between Pi signaling and hormone signaling pathways. Additionally, ZmSPXs displayed tissue-specific expression patterns, with significant and differential induction in anthers and roots, and were localized to the nucleus and cytoplasm. The interaction between ZmSPXs and ZmPHRs was established via yeast two-hybrid assays. Furthermore, overexpression of ZmSPX1 enhanced root sensitivity to Pi deficiency and high-Pi conditions in Arabidopsis thaliana. Phenotypic identification of the maize transgenic lines demonstrated the negative regulatory effect on the P concentration of stems and leaves as well as yield. Notably, polymorphic sites including 34 single-nucleotide polymorphisms (SNPs) and seven insertions/deletions (InDels) in ZmSPX1 were significantly associated with 16 traits of low-Pi tolerance index. Furthermore, significant sites were classified into five haplotypes, and haplotype5 can enhance biomass production by promoting root development. Taken together, our results suggested that ZmSPX family members possibly play a pivotal role in Pi stress signaling in plants by interacting with ZmPHRs. Significantly, ZmSPX1 was involved in the Pi-deficiency response verified in transgenic Arabidopsis and can affect the Pi concentration of maize tissues and yield. This work lays the groundwork for deeper exploration of the maize SPX family and could inform the development of maize varieties with improved Pi efficiency.

Sargassum seaweed extract regulates physio-molecular patterns in Sesamum indicum L. towards better growth and Macrophomina tolerance

Seaweed extracts have gained significant attention in agriculture as they contain biologically active components that promote plant growth, increase productivity and stress signalling pathways for disease tolerance. The present study, reveal the positive effect of Sargassum tenerrimum extract on Sesamum indicum L. at both vegetative and reproductive stages towards enhancing tolerance against charcoal rot disease caused by Macrophomina phaseolina. The application of S. tenerrimum extract alone and in combination with Macrophomina enhanced the plant's growth and yield. In both stages, the S. tenerrimum extract alone and in combination with Macrophomina resulted in increased membrane stability index, photosynthetic pigments and osmolytes as compared to control and Macrophomina treatment. Significant decrease in the accumulation of reactive oxygen species was observed in combined treatment as compared to Macrophomina treatment alone in both the stages with both sprays. Antioxidative enzymes exhibited higher accumulation in S. tenerrimum extract treatment and in combination during both sprays at both stages. The improved yield was observed with the applications of S. tenerrimum extract at both stages. Consequently, this study highlights the beneficial role of S. tenerrimum extract in managing diseases in S. indicum by modulating physio-biochemical pathways for improved growth and yield.

The VAMP-associated protein VAP27-1 plays a crucial role in plant resistance to ER stress by modulating ER–PM contact architecture in Arabidopsis

The endoplasmic reticulum (ER) and the plasma membrane (PM) form ER–PM contact sites (EPCSs) that allow the ER and PM to exchange materials and information. Stress-induced disruption of protein folding triggers ER stress, and the cell initiates the unfolded protein response (UPR) to resist the stress. However, whether EPCSs play a role in ER stress in plants remains unclear. VESICLE-ASSOCIATED MEMBRANE PROTEIN (VAMP)-ASSOCIATED PROTEIN 27-1 (VAP27-1) functions in EPCS tethering and is encoded by a family of 10 genes (VAP27-1–10) in Arabidopsis thaliana. Here, we used CRISPR-Cas9-mediated genome editing to obtain a homozygous vap27-1 vap27-3 vap27-4 (vap27-1/3/4) triple mutant lacking three of the key VAP27 family members in Arabidopsis. The vap27-1/3/4 mutant exhibits defects in ER–PM connectivity and EPCS architecture, as well as excessive UPR signaling. We further showed that relocation of VAP27-1 to the PM mediates specific VAP27-1-related EPCS remodeling and expansion under ER stress. Moreover, the spatiotemporal dynamics of VAP27-1 at the PM increase ER–PM connectivity and enhance Arabidopsis resistance to ER stress. In addition, we revealed an important role for intracellular calcium homeostasis in the regulation of UPR signaling. Taken together, these results broaden our understanding of the molecular and cellular mechanisms of ER stress and UPR signaling in plants, providing additional clues for improving plant broad-spectrum resistance to different stresses.

Stress Knowledge Map: A knowledge graph resource for systems biology analysis of plant stress responses

Stress Knowledge Map (SKM; https://skm.nib.si) is a publicly available resource containing two complementary knowledge graphs that describe the current knowledge of biochemical, signaling, and regulatory molecular interactions in plants: a highly curated model of plant stress signaling (PSS; 543 reactions) and a large comprehensive knowledge network (488 390 interactions). Both were constructed by domain experts through systematic curation of diverse literature and database resources. SKM provides a single entry point for investigations of plant stress response and related growth trade-offs, as well as interactive explorations of current knowledge. PSS is also formulated as a qualitative and quantitative model for systems biology and thus represents a starting point for a plant digital twin. Here, we describe the features of SKM and show, through two case studies, how it can be used for complex analyses, including systematic hypothesis generation and design of validation experiments, or to gain new insights into experimental observations in plant biology.

Phosphatidic acid formation and signaling in plant cells

This review conteins updated information on the structure, localization and regulation of phosphatidic acid (PA)-producing enzymes phospholipase D, phosphoinositide-specific and non-specific phospholipases C and diacylglycerol kinases is analyzed. The specific role of PA and PA-producing enzymes in plant stress signaling is discussed.

Cysteine thiol sulfinic acid in plant stress signaling.

Cysteine thiols are susceptible to various oxidative posttranslational modifications (PTMs) due to their high chemical reactivity. Thiol-based PTMs play a crucial role in regulating protein functions and are key contributors to cellular redox signaling. Although reversible thiol-based PTMs, such as disulfide bond formation, S-nitrosylation, and S-glutathionylation, have been extensively studied for their roles in redox regulation, thiol sulfinic acid (-SO2H) modification is often perceived as irreversible and of marginal significance in redox signaling. Here, we revisit this narrow perspective and shed light on the redox regulatory roles of -SO2H in plant stress signaling. We provide an overview of protein sulfinylation in plants, delving into the roles of hydrogen peroxide-mediated and plant cysteine oxidase-catalyzed formation of -SO2H, highlighting the involvement of -SO2H in specific regulatory signaling pathways. Additionally, we compile the existing knowledge of the -SO2H reducing enzyme, sulfiredoxin, offering insights into its molecular mechanisms and biological relevance. We further summarize current proteomic techniques for detecting -SO2H and furnish a list of experimentally validated cysteine -SO2H sites across various species, discussing their functional consequences. This review aims to spark new insights and discussions that lead to further investigations into the functional significance of protein -SO2H-based redox signaling in plants.

Plant growth-promoting rhizobacteria: Influence to abiotic stress tolerance in rice (Oryza sativa L.)

Plant growth-promoting rhizobacteria (PGPR) has been shown to govern a number of aspects of plant development, enabling the plant to survive and adapt to its surroundings, in response to unfavorable conditions that are abiotic in nature. As a staple crop, rice is particularly vulnerable to a variety of abiotic stresses including drought, salt, heavy metal toxicity, and high temperatures. In tandem, these stresses have a significant detrimental impact on rice productivity and quality. PGPR is a rhizosphere-dwelling microorganism that can improve plant development through a variety of distinctive methods, including nutrient uptake, phytohormone synthesis, modification of plant stress signaling pathways, and stimulation of stress-responsive genes. In this review, we studied the several abiotic pressures that are encountered and how PGPR can aid in resisting the stresses with a focus on rice crop, we additionally look at how PGPR minimize the dependency of agricultural soils on pesticides and chemical fertilizers. PGPR contributes to the long-term sustainability of ecosystems, plant productivity, and soil health by promoting environmentally friendly and sustainable farming practices.

DPY1 as an osmosensor for drought signaling

Drought stress has been extensively studied for its effect on the downstream signaling cascade and stress-responsive gene expression, but understanding the process has remained elusive. Recently, Zhao et al. identified DROOPY LEAF1 (DPY1) as an osmosensor and revealed a novel mechanism of DPY1-STRESS ACTIVATED PROTEIN KINASE6 (SAPK6)-mediated drought stress signaling in higher plants.

Genome wide identification and expression profiling of PYL genes in barley

PYLs (pyrabactin resistance1/PYR1-like) sense ABA, an essential phytohormone that regulates plant growth and stress responses. PYLs act as the main controllers of ABA stress signaling in plants. In this study, a total of 10 HvPYLs were discovered in the barley genome using an in silico genome search technique. These HvPYLs were then grouped into 3 subfamilies based on a phylogenetic analysis that compared them to the genomes of Arabidopsis, Brachypodium, rice, and maize. These HvPYLs demonstrated conserved motif compositions and identical protein structures across clades. Additionally, this study includes detailed investigations of gene structure variations, chromosomal distributions, cis-regulatory elements, protein-protein interactions, expression profiles in different tissues, and stress responses. We identified various cis-elements in the HvPYL promoter regions related to plant development and stresses indicating their potential roles in development and stress management. Our analysis of the interaction network has identified that HvPYLs can interact with key components of the ABA signaling pathway, demonstrating the critical regulatory functions of HvPYL genes in managing stress and growth in barley. These findings provide a basis for future research aimed at exploring the functions of PYL genes, with the ultimate goal of enhancing stress tolerance in barley and other related species.

The osmotic stress-activated receptor-like kinase DPY1 mediates SnRK2 kinase activation and drought tolerance in Setaria.

Plant genomes encode many receptor-like kinases (RLKs) that localize to the cell surface and perceive a wide variety of environmental cues to initiate downstream signaling cascades. Whether these RLKs participate in dehydration stress signaling in plants is largely unknown. DROOPY LEAF1 (DPY1), a leucine-rich repeat (LRR)-RLK, was recently shown to regulate plant architecture by orchestrating early brassinosteroid signaling in foxtail millet (Setaria italica). Here, we show that DPY1 is essential for the acclimation of foxtail millet to drought stress. DPY1 can be phosphorylated and activated in response to osmotic stress and is required for more than half of osmotic stress-induced global phosphorylation events, including the phosphorylation of sucrose nonfermenting kinase 2s (SnRK2s), the central kinases involved in osmotic stress. DPY1 acts upstream of STRESS-ACTIVATED PROTEIN KINASE 6 (SAPK6, a subclass I SnRK2) and is required for full SAPK6 activation, thereby allowing regulation of downstream genes to mount a response against drought stress. These signaling events are largely independent of DPY1-mediated brassinosteroid signaling. The DPY1-SAPK6 module is specific to seed plants and is absent in ancestral nonseed plants. Our findings reveal a dehydration stress-activated RLK that plays an indispensable role in osmotic stress signaling and mediates SnRK2 activation at the cell surface.

The Role of Long-Distance Mobile Metabolites in Plant Stress Response and Signaling.

Plants developed sophisticated mechanisms to receive environmental stimuli and generate appropriate signals to maintain optimal growth and stress responses. A fascinating strategy employed by plants is the use of long-distance mobile signals which can trigger local and distant responses across the entire plant. Some metabolites play a central role as long-distance mobile signals allowing plants to communicate across tissues and mount robust stress responses. In the review, we summarize the current state of knowledge regarding the various long-distance mobile metabolites and their function in stress response and signaling pathways. We also raise questions with respect to how can we identify new mobile metabolites and engineer them to improve plant health and resilience.

Integration of multiple stress signals in plants using synthetic Boolean logic gates.

As photosynthetic organisms, plants have a potential role in the sustainable production of high-value products such as medicines, biofuels, and chemical feedstocks. With effective engineering using synthetic biology approaches, plant-based platforms could conceivably be designed to minimize the costs and waste of production for materials that would otherwise be uneconomical. Additionally, modern agricultural crops could be engineered to be more productive, resilient, or restorative in different or rapidly changing environments and climates. Information-processing genetic devices and circuits containing multiple interacting parts that behave predictably must be developed to achieve these complex goals. A genetic Boolean AND logic gate is a device that computes the presence or absence of 2 inputs (signals and stimuli) and produces an output (response) only when both inputs are present. We optimized individual genetic components and used synthetic protein heterodimerizing domains to rationally assemble genetic AND logic gates that integrate 2 hormonal inputs in transgenic Arabidopsis thaliana plants. These AND gates produce an output only in the presence of both abscisic acid and auxin but not when either or neither hormone is present. The AND logic gate can also integrate signals resulting from 2 plant stresses, cold temperature and bacterial infection, to produce a response. The design principles used here are generalizable, and, therefore, multiple orthogonal AND gates could be assembled and rationally layered to process complex genetic information in plants. These layered logic gates may be used in genetic circuits to probe fundamental questions in plant biology, such as hormonal crosstalk, in addition to plant engineering for bioproduction.

Deficiency of the Arabidopsis mismatch repair MSH6 attenuates Pseudomonas syringae invasion

The MutS homolog 6 (MSH6) is a nuclear DNA mismatch repair (MMR) gene that encodes the MSH6 protein. MSH6 interacts with MSH2 to form the MutSα heterodimer. MutSα corrects DNA mismatches and unpaired nucleotides arising during DNA replication, deamination of 5-methylcytosine, and recombination between non-identical DNA sequences. In addition to correcting DNA biosynthetic errors, MutSα also recognizes chemically damaged DNA bases. Here, we show that inactivation of MSH6 affects the basal susceptibility of Arabidopsis thaliana to Pseudomonas syringae pv tomato DC3000. The msh6 T-DNA insertional mutant exhibited a reduced susceptibility to the bacterial invasion. This heightened basal resistance of msh6 mutants appears to be dependent on an increased stomatal closure, an accumulation of H2O2 and double-strand breaks (DSBs) and a constitutive expression of pathogenesis-related (NPR1 and PR1) and DNA damage response (RAD51D and SOG1) genes. Complementation of this mutant with the MSH6 wild type allele under the control of its own promoter resulted in reversal of the basal bacterial resistance phenotype and the stomatal closure back to wild type levels. Taken together, these results demonstrate that inactivation of MSH6 increases Arabidopsis basal susceptibility to the bacterial pathogen and suggests a link between DNA repair and stress signaling in plants.

Outcome of Microalgae Biomass Application on Seed Germination and Hormonal Activity in Winter Wheat Leaves

The present work aimed to test selected microalgae strains from the Mosonmagyaróvár Algae Culture Collection (MACC) on germination ability and certain physiological processes in winter wheat (Triticum aestivum L.) plants. Germination tests showed substantial differences between the strains, meaning that certain strains (such as MACC-430, MACC-612, MACC-922) improved the germination processes while others performed worse (MACC-438, MACC-755) than the control in a concentration-dependent manner. The germination index of seeds treated with MACC-430 @ 1 g L−1 concentrations was 87, while that of the control was 45. The mungbean rooting bioassay proves that microalgae biomass may exhibit auxin-like activity, especially in strain MACC-612 (Nostoc sp.), which was characterized by the highest endogenous level of plant growth regulator indole-3-acetic-acid among the selected strains. Foliar spray on the leaves of developed plants did not significantly alter the photosynthetic processes, but it influenced the secondary metabolite composition. After the application of microalgae biomass, there were also changes in plant hormones, including salicylic acid, abscisic acid, and jasmonic acid-leucine/isoleucine conjugate compositions, which play a role in plant stress signaling in plants. A decrease in indole-3-acetic acid was also observed in the Mv Nádor cultivar. These results suggest that the application of certain microalgae strains can be used effectively to improve the germination of wheat seeds, and as a foliar spray, they may also modify the acclimation processes in a genotype-dependent way.

Calcium-dependent activation of CPK12 facilitates its cytoplasm-to-nucleus translocation to potentiate plant hypoxia sensing by phosphorylating ERF-VII transcription factors

Calcium-dependent protein kinases (CDPKs/CPKs) are key regulators of plant stress signaling that translate calcium signals into cellular responses by phosphorylating diverse substrate proteins. However, the molecular mechanism by which plant cells relay calcium signals in response to hypoxia remains elusive. Here, we show that one member of the CDPK family in Arabidopsis thaliana, CPK12, is rapidly activated during hypoxia through calcium-dependent phosphorylation of its Ser-186 residue. Phosphorylated CPK12 shuttles from the cytoplasm to the nucleus, where it interacts with and phosphorylates the group VII ethylene-responsive transcription factors (ERF-VII) that are core regulators of plant hypoxia sensing, to enhance their stabilities. Consistently, CPK12 knockdown lines show attenuated tolerance of hypoxia, whereas transgenic plants overexpressing CPK12 display improved hypoxia tolerance. Nonethelss, loss of function of five ERF-VII proteins in an erf-vii pentuple mutant could partially suppress the enhanced hypoxia-tolerance phenotype of CPK12-overexpressing lines. Moreover, we also discovered that phosphatidic acid and 14-3-3κ protein serve as positive and negative modulators of the CPK12 cytoplasm-to-nucleus translocation, respectively. Taken together, these findings uncover a CPK12-ERF-VII regulatory module that is key to transducing calcium signals from the cytoplasm into the nucleus to potentiate hypoxia sensing in plants.

Genome-Wide Identification of Sweet Orange WRKY Transcription Factors and Analysis of Their Expression in Response to Infection by Penicillium digitatum.

WRKY transcription factors (TFs) play a vital role in plant stress signal transduction and regulate the expression of various stress resistance genes. Sweet orange (Citrus sinensis) accounts for a large proportion of the world's citrus industry, which has high economic value, while Penicillium digitatum is a prime pathogenic causing postharvest rot of oranges. There are few reports on how CsWRKY TFs play their regulatory roles after P. digitatum infects the fruit. In this study, we performed genome-wide identification, classification, phylogenetic and conserved domain analysis of CsWRKY TFs, visualized the structure and chromosomal localization of the encoded genes, explored the expression pattern of each CsWRKY gene under P. digitatum stress by transcriptome data, and made the functional prediction of the related genes. This study provided insight into the characteristics of 47 CsWRKY TFs, which were divided into three subfamilies and eight subgroups. TFs coding genes were unevenly distributed on nine chromosomes. The visualized results of the intron-exon structure and domain are closely related to phylogeny, and widely distributed cis-regulatory elements on each gene played a global regulatory role in gene expression. The expansion of the CSWRKY TFs family was probably facilitated by twenty-one pairs of duplicated genes, and the results of Ka/Ks calculations indicated that this gene family was primarily subjected to purifying selection during evolution. Our transcriptome data showed that 95.7% of WRKY genes were involved in the transcriptional regulation of sweet orange in response to P. digitatum infection. We obtained 15 differentially expressed genes and used the reported function of AtWRKY genes as references. They may be involved in defense against P. digitatum and other pathogens, closely related to the stress responses during plant growth and development. Two interesting genes, CsWRKY2 and CsWRKY14, were expressed more than 60 times and could be used as excellent candidate genes in sweet orange genetic improvement. This study offers a theoretical basis for the response of CSWRKY TFs to P. digitatum infection and provides a vital reference for molecular breeding.

Insights into strigolactone (GR24) mediated regulation of cadmium-induced changes and ROS metabolism in Artemisia annua

Agricultural soil contamination and subsequently crops still require alternative solutions to reduce associated environmental risks. The effects of strigolactones (SLs) in alleviating cadmium (Cd) phytotoxicity in Artemisia annua plants were investigated during this study. Strigolactones play a vital role during plant growth and development due to their complex interplay during a plethora of biochemical processes. However, information on the potential of SLs to elicit abiotic stress signaling and trigger physiological modifications in plants is limited. In order to decipher the same, A. annua plants were exposed to different concentrations of Cd (20 and 40 mg kg-1), with or without the supplementation of exogenous SL (GR24, a SL analogue) at 4 µM concentration. Under Cd stress, excess Cd accumulation resulted in reduced growth, physio-biochemical traits, and artemisinin content. However, the follow-up treatment of GR24 maintained a steady state equilibrium between reactive oxygen species and antioxidant enzymes, improved chlorophyll fluorescence parameters such as Fv/Fm, ФPSII, and ETR for improved photosynthesis, enhanced chlorophyll content, maintained chloroplast ultrastructure, improved the glandular trichome (GT) attributes and artemisinin production in A. annua. Moreover, it also resulted in improved membrane stability, reduced Cd accumulation, and regulated the behaviour of stomatal apertures for better stomatal conductance under Cd stress. The results of our study suggest that GR24 could be highly effective in alleviating Cd-induced damages in A. annua. It acts via the modulation of the antioxidant enzyme system for redox homeostasis, protection of the chloroplasts and pigments for improved photosynthetic performance, and improved GT attributes for enhanced artemisinin production in A. annua.

Comprehensive analysis of LRR-RLKs and key gene identification in Pinus massoniana resistant to pine wood nematode.

Pinus massoniana is a pioneer tree widely planted for afforestation on barren hills in southern China where the total planted area is 8.04 million ha. The invasive pine wood nematode (Bursaphelenchus xylophilus) poses a serious threat to the survival of P. massoniana. Plant resistance genes encoded by leucine-rich repeat-containing transmembrane-receptor proteins play important roles in plant defense. Leucine-rich repeat receptor-like kinases (LRR-RLKs), the largest subfamily of the RLK protein family, play an important role in sensing stress signals in plants. However, the LRR-RLKs of P. massoniana have not been characterized previously, and their role in resistance to B. xylophilus is unknown. In this study, 185 members of the LRR-RLK subfamily were identified in P. massoniana and were categorized into 14 subgroups. Transcriptomic and quantitative real-time RT-PCR analyses showed that PmRLKs32 was highly expressed in the stem tissue after inoculation with B. xylophilus. The gene exhibited high homology with AtFLS2 of Arabidopsis thaliana. PmRLKs32 was localized to the plasma membrane and was significantly upregulated in nematode-resistant and nematode-susceptible individuals. The transient expression of PmRLKs32 resulted in a burst of reactive oxygen species production in P. massoniana and Nicotiana benthamiana seedlings. These results lay a foundation for further exploration of the regulatory mechanism of LRR-RLKs in response to biotic stress in P. massoniana.

Transcript profiling of Polycomb gene family in Oryza sativa indicates their abiotic stress-specific response.

The precise regulation of gene expression is required for the determination of cell fate, differentiation, and developmental programs in eukaryotes. The Polycomb Group (PcG) genes are the key transcriptional regulators that constitute the repressive system, with two major protein complexes, Polycomb Repressive Complex 1 (PRC1) and Polycomb Repressive Complex 2 (PRC2). Previous studies have demonstrated the significance of these proteins in regulation of normal growth and development processes. However, the role of PcG in adaptation of crops to abiotic stress is still not well understood. The present study aimed to a comprehensive genome-wide identification of the PcG gene family in one of the economically important staple crops, Oryza sativa. Here, a total of 14 PcG genes have been identified, which were distributed over eight chromosomes. Protein structure analysis revealed that both the complexes have distinct domain and motifs that are conserved within the complexes. In silico promoter analysis showed that PcG gene promoters have abundance of abiotic stress-responsive elements. RNA-seq based expression analysis revealed that PcG genes are differentially expressed in different tissues and responded variably in different environmental stress. Validation of gene expression by qRT-PCR showed that most of the genes were upregulated at 1-h time point in shoot tissue and at 24-h time point in root tissue under the drought and salinity stress conditions. These findings provide important and extensive information on the PcG family of O. sativa, which will pave the path for understanding their role in stress signaling in plants.