Search Results (50)

The plant hormone abscisic acid (ABA) plays a crucial role throughout the plant life cycle and in adaptive responses to environmental stresses. The pyrabactin resistance 1-like (PYR/PYL/RCAR) proteins act as key regulators in the ABA signal transduction pathway by functioning as direct receptors for ABA. Although PYL genes have been identified in a variety of plant species, their evolutionary and structural characteristics in tomatoes (Solanum lycopersicum) remain elusive. To address this gap, we identified nine SlPYL genes, which were classified into three subfamilies: I (two genes), II (three genes), and III (four genes), and their encoded proteins were predicted to be primarily localized in the cytosol and chloroplast. Structural analysis revealed diverse exon–intron organizations along with five conserved motifs. All identified SlPYLs contained the START domain (PF10604), validating their identity as actual PYL proteins. Prediction of cis-acting regulatory elements in SlPYL’s promoter regions was found to be associated with light responsiveness, hormone signaling, stress responses, and plant growth and development. Prediction of post-translational modification sites indicated that SlPYLs are predominantly phosphorylated and acetylated at serine and lysine residues, respectively. Tertiary structure modeling demonstrated conserved three-dimensional architectures among SlPYL proteins, supporting their functional conservation. Expression profiling revealed that specific SlPYL genes exhibit distinct expression patterns across different tissues (root, leaf, and bud) following ABA treatment, indicating functional diversification. Considering the well-established negative correlation between ABA accumulation and bud outgrowth, the ABA-induced differential expression (3~5-fold) of some SlPYL genes (SlPYL3, SlPYL4, SlPYL7, and SlPYL8), particularly in bud tissues after 24 hpt, suggests a potential role in ABA-mediated suppression of bud outgrowth. However, these functional inferences are primarily based on genome-wide computational analyses and expression profiling and therefore require further experimental validation. Full article

Wheat is a globally important staple crop, whose growth and yield formation rely on the precise regulation of phytohormone signaling. The PR10/Bet v 1 (Pathogenesis-related protein 10/Betula verrucosa 1) family consists of conserved small-molecule ligand-binding proteins that participate in phytohormone signaling and plant development; however, systematic investigations of this family in wheat remain limited. Here, we performed a genome-wide identification of 75 PR10/Bet v 1 members in wheat, which were phylogenetically classified into three subfamilies: 21 known members belonging to the PYL (Pyrabactin resistance 1-like) subfamily, and 54 members assigned to two previously uncharacterized subfamilies. Bioinformatic analyses revealed that whole-genome/segmental duplication has driven the expansion of this gene family, which has evolved under strong purifying selection. Expression profiling and promoter analysis revealed differential expression patterns, along with abundant cis-acting elements responsive to multiple hormones. Quantitative RT-PCR (qRT-PCR) of 12 representative genes revealed marked transcriptional changes in several members within 1 h of treatment with BR (Brassinosteroid), ABA (Abscisic acid), CK (Cytokinin), or SA (Salicylic acid) suggesting that these genes may be directly involved in hormone-regulated processes. This study provides a fundamental framework for exploring the regulatory functions of the wheat PR10/Bet v 1 family, and valuable hormone-responsive candidate genes for the genetic improvement of wheat agronomic traits. Full article

The seeds of Polygonatum sibiricum exhibit dormancy, which poses a major challenge for its cultivation. To elucidate the regulatory mechanisms underlying dormancy release, we performed integrated transcriptomic and metabolomic analyses on seeds at 0, 5, 10, and 15 d after seed imbibition. Physiological assays revealed progressive declines in abscisic acid (ABA) and starch levels, alongside increases in gibberellin (GA) and soluble sugar contents, reflecting the metabolic changes accompanying the transition from dormancy to germination. Transcriptomic analysis identified 11,520 expressed genes, with 6753, 7775 and 9387 differentially expressed genes (DEGs) at T5, T10, and T15, respectively. KEGG enrichment highlighted starch and sucrose metabolism and plant hormone signal transduction as key pathways. Notably, the GA biosynthesis gene GA3ox was markedly upregulated, while the DELLA repressor (Isoform0012761) showed sustained downregulation, suggesting relieved GA signaling. In the ABA pathway, CYP707A catabolic genes exhibited biphasic expression, and ABA signaling components (PYL, PP2C, SnRK2) showed stage-specific remodeling. A total of 316, 412, and 479 differentially expressed transcription factors were identified across stages, with the GRAS family being the largest. Co-expression network analysis revealed 19 transcription factors integrating starch/sucrose metabolism with ABA and GA signaling, most of which were downregulated, except one C2H2 member showing sustained upregulation. These findings demonstrate that dormancy release in P. sibiricum is governed by coordinated hormonal reprogramming, metabolic mobilization, and transcription factor-mediated regulation, providing a theoretical foundation for improving seed germination in this medicinal plant. Full article

Brassica napus L. is a major oilseed crop whose productivity is significantly affected by abiotic stresses such as drought. PYR/PYL/RCAR (PYL) proteins act as key abscisic acid (ABA) receptors and play central roles in stress responses. However, a comprehensive genome-wide analysis of the PYL gene family in B. napus is still lacking, limiting our understanding of their functions in plant and stress adaptation. This study reports the first comprehensive genome-wide analysis of the PYL gene family in B. napus (rapeseed), cultivar ZS11, identifying 25 BnPYL genes grouped into four subfamilies, I (four genes), I-II (five genes), II (five genes), III (11 genes), and their encoded proteins were predicted to be mainly localized in the chloroplast. Structural analysis revealed diverse exon–intron organization and 10 conserved motifs. All identified BnPYLs contained Polyketide_cyc2 domains (PF10604), supporting their annotation as members of the PYL family. Promoter analysis identified cis-regulatory elements related to light response, stress regulation, and hormonal signaling. Computational analysis of post-translational modifications suggested that phosphorylation sites are mainly localized at serine and threonine residues. Tertiary structure modelling revealed conserved three-dimensional architectures among BnPYL proteins, suggesting potential functional conservation. Expression profiling and RT-qPCR analyses revealed that several BnPYL genes respond to ABA-mediated drought stress, with BnPYL15 and BnPYL22 exhibiting the highest induction (4–5-fold) and BnPYL2, BnPYL5, BnPYL6, BnPYL17, BnPYL18, and BnPYL25 showing significant upregulation (2.0–4.5-fold), suggesting potential roles in enhancing drought tolerance in B. napus. Full article

Panax ginseng is a medicinal plant with diverse pharmacological effects; its primary active components are ginsenosides. The biosynthesis of ginsenosides can be regulated by the plant hormone methyl jasmonate (MeJA) during in vitro culture of ginseng. The PYL proteins, which serve as abscisic acid (ABA) receptors, play a crucial role in plant hormone signaling transduction. However, there are no reports on the response of PYL genes to MeJA in ginseng. In this study, we identified 49 members of the PYL gene family in the ginseng genome and transcriptome from databases and conducted a systematic analysis. The results indicated that these PYL genes were unevenly distributed across the chromosomes and exhibited significant synteny. Gene Ontology (GO) functional annotation revealed considerable functional diversity in the PYL gene family in ginseng. Analysis of the promoter cis-acting elements showed that these genes are involved in various biological processes, including growth, development, and metabolic regulation. After treating ginseng adventitious roots with MeJA, we found that four PgPYL genes (PgPYL13, PgPYL17-01, PgPYL17-02, and PgPYL23) containing abundant MeJA-responsive elements exhibited distinct expression patterns and were negatively correlated with protopanaxadiol-type ginsenoside content. This study systematically elucidated the characteristics and functions of the ginseng PYL gene family, revealing its potential role in MeJA signal transduction and the regulation of ginsenoside biosynthesis. Our findings provide a theoretical basis for optimizing the in vitro culture of ginseng plant cells and enhancing ginsenoside production. Full article

Background: PYR/PYL/RCAR proteins are core abscisic acid (ABA) receptors that play essential roles in ABA signal transduction, plant growth and development, and abiotic stress responses. However, the PYL gene family in watermelon (Citrullus lanatus) has not been systematically characterized, limiting our understanding of ABA-mediated stress adaptation in this economically important crop. Methods: A genome-wide analysis was performed to identify ClPYL genes in watermelon using a hidden Markov model search. Phylogenetic relationships were reconstructed using the maximum likelihood method. Segmental duplication events were analyzed using synteny analysis. Conserved motifs, gene structures, and promoter cis-acting elements were characterized using MEME and PlantCARE. Expression profiles under drought, salt, and cold stresses were examined by quantitative real-time PCR (qRT-PCR) with three biological replicates. Results: In this study, 15 ClPYL genes were identified in watermelon through genome-wide analysis. Phylogenetic reconstruction classified these genes into four subfamilies, with subfamily II being exclusively present in cucurbits—a lineage-specific feature not observed in Arabidopsis. Synteny analysis revealed eight segmental duplication events involving members of subfamilies I, III, and IV, while subfamily II members were not associated with these duplications. Members within the same subfamily share similar exon-intron structures and conserved motifs. Promoter analysis revealed that ClPYL genes are enriched with various cis-acting elements associated with hormone signaling and abiotic stress responses. Expression profiling demonstrated that ClPYL genes exhibit diverse and dynamic expression patterns under drought, high-salinity, and cold stresses. Notably, genes such as ClPYL5 under drought, ClPYL02 under salt, and ClPYL15 under cold stress displayed persistent stress-responsive expression. Conclusions: These findings reveal the evolutionary conservation and diversification of the PYL family in watermelon and provide a set of candidate genes for functional studies aimed at dissecting ABA-mediated stress adaptation. This work establishes a genomic framework for developing stress-resilient watermelon varieties through molecular breeding. Full article

PYL proteins are core components of the abscisic acid (ABA) signaling pathway and are involved in plant responses to biotic and abiotic stresses. In this study, a total of 19, four, and eight PYL genes were identified in Saccharum spontaneum, the Saccharum spp. hybrid R570, and Sorghum bicolor, respectively. Phylogenetic analysis classified these PYL genes into three distinct groups. Cis-acting element analysis, Gene Ontology annotation, and Kyoto Encyclopedia of Genes and Genomes pathway enrichment and gene expression profile indicated that members of the PYL gene family are mainly associated with hormone signaling and stress-related biological processes. The ScPYL8 gene (GenBank accession number: OR838856) was isolated from sugarcane cultivar QT3. Expression of the ScPYL8 gene was induced under stresses of cold, PEG, SA, MeJA, ABA, and brown stripe disease (Bipolaris setariae). The gene was expressed in roots, stems and leaves, with the highest expression level in leaves. Subcellular localization analysis showed that the ScPYL8 protein localized to the cytoplasm and nucleus. ScPYL8 overexpression in tobacco activated the reactive oxygen species defense system and regulated the ABA and jasmonic acid signaling pathways, enhancing its resistance against Fusarium solani var. coeruleum. These findings provide insights into the expression, function, and evolutionary characteristics of the PYL gene family in sugarcane, offering valuable genetic resources for future molecular breeding. Full article

Eucalyptus is a highly diverse genus of the Myrtaceae family that is planted worldwide. Many changes occur during callus development, an important process during in vitro plant regeneration. In this study, we conducted methylome and transcriptome analyses to reveal such changes. The results showed that differentially expressed genes between E. camaldulensis (voucher ID: c0009; high embryogenic potential) and E. grandis × urophylla (voucher ID: j0017; low embryogenic potential) during callus development were enriched in plant hormone signal transduction and MAPK (Mitogen-activated protein kinase) signaling pathways. qRT-PCR analysis showed AHP, BAK1, BSK, CRE1, GID1, MKS1, PR-1, PYL, RbohD, and TCH4 could be involved in the callus development and plantlet regeneration capacity. The differences observed in regenerative potential during callus maturation between the two species under study provide a reliable molecular basis for the study of Eucalyptus regeneration mechanisms. Full article

Background/Objectives: Carotenoids in citrus are vital nutritional compounds and precursors of the stress hormone abscisic acid (ABA). SNF1-related kinases (SnRKs)—key regulators of plant stress signaling that phosphorylate is targeting proteins for post-transcriptional regulation—mediate ABA signaling through its subfamily SnRK2-phosphatase type-2C (PP2C)-PYR1-LIKE (PYL) cascades. This study aims to identify the SnRK-PP2C-PYL family members and decipher their underlying post-transcriptional regulatory mechanisms which control carotenoid metabolism in Citrus sinensis for improved nutrition and stress resilience. Methods: SnRK, PP2C, and PYL were identified by integrated HMMER-blastp-CDD pipeline in the Citrus genome. Using two carotenoid-divergent cultivars, ‘Newhall’ (yellow) and ‘Cara Cara’ (red, hyperaccumulating linear carotenoids), we conducted spatiotemporal expression profiling and integrated transcriptomic and metabolomic data via Weighted Gene Co-expression Network Analysis (WGCNA) to identify modules correlated with accumulation. Results: We identified 26 CsSnRKs (1 SnRK1, 7 SnRK2, 18 SnRK3), 57 CsPP2Cs, and 7 CsPYLs in Citrus sinensis. Despite a >26-fold difference in linear carotenoids, structural gene expression was similar among cultivars, strongly implicating post-transcriptional control. WGCNA identified a key turquoise module highly correlated with linear carotenoid content. This module contained phosphorylation-related genes (CsSnRK1/3.5/3.6/3.16, CsPP2C14/15/33/35/38/40/43/56, and CsPYL6), biosynthetic genes (CsPSY1, CsZISO, and CsZDS), and candidate transcription factors. Network analysis predicted that CsSnRKs, CsPP2Cs, and CsPYLs regulate phytoene-derived carotenoid biosynthesis. Conclusions: We propose a novel phosphorylation-mediated post-transcriptional regulatory network in carotenoid accumulation. This mechanism bridges ABA signaling and metabolic adaptation, providing crucial molecular targets for engineering nutrient-dense and climate-resilient citrus varieties. Full article

PYR/PYL (pyrroloquinoline quinone resistance/PYR1-like) are receptors for abscisic acid (ABA) in plants and play a crucial role in responses to abiotic stress. In this study, we identified 63 members of the StPYL gene family at the tetraploid whole-genome level in potatoes. We analyzed the physicochemical properties of these 63 StPYLs and constructed a phylogenetic tree using Arabidopsis thaliana and potato (Solanum tuberosum L.) cultivar ‘DM’ as the reference. By examining gene structure, conserved protein motifs, and collinearity, we found that StPYLs are highly conserved throughout evolution. The gene expression heat map under salt stress revealed that 57 StPYL genes are involved in the salt stress response. Among them, the expression level of StPYL9a-like changed significantly under salt stress. Through genetic transformation, we observed that overexpression of StPYL9a-like enhanced the growth and survival of potato plants under salt stress compared to the wild type. The contents of proline (Pro), superoxide dismutase (SOD), and chlorophyll in the leaves of overexpressing plants increased, while malondialdehyde (MDA) levels decreased. This suggests that StPYL9a-like positively regulates salt tolerance by affecting antioxidant enzyme activity and osmotic adjustment substances in potatoes. Subcellular localization demonstrated that StPYL9a-like is localized in the nucleus. This study provides a reference for the functional research of PYLs in potatoes, offers a basis for screening potato genes related to salt stress, and lays a foundation for developing salt-tolerant potato varieties. Full article

Abscisic acid (ABA) is a key phytohormone involved in regulating plant growth and responses to environmental stress. As receptors of ABA, pyrabactin resistance 1 (PYR)/PYR1-like (PYL) proteins play a central role in initiating ABA signal transduction. In this study, a total of 30 PopPYL genes were identified and classified into three sub-families (PYL I–III) in the pan-genome of 17 Populus species, through phylogenetic analysis. Among these subfamilies, the PYL I subfamily was the largest, comprising 21 members, whereas PYL III was the smallest, with only four members. To elucidate the evolutionary dynamics of these genes, we conducted synteny and Ka/Ks analyses. Results indicated that most PopPYL genes had undergone purifying selection (Ka/Ks < 1), while a few were subject to positive selection (Ka/Ks > 1). Promoter analysis revealed 258 cis-regulatory elements in the PYL genes of Populus euphratica (EUP) and Populus pruinosa (PRU), including 127 elements responsive to abiotic stress and 33 ABA-related elements. Furthermore, six structural variations (SVs) were detected in PYL_EUP genes and significantly influenced gene expression levels (p < 0.05). To further explore the functional roles of PYL genes, we analyzed tissue-specific expression profiles of 17 PYL_EUP genes under drought stress conditions. PYL6_EUP was predominantly expressed in roots, PYL17_EUP exhibited leaf-specific expression, and PYL1_EUP showed elevated expression in stems. These findings suggest that the drought response of PYL_EUP genes is tissue-specific. Overall, this study highlights the utility of pan-genomics in elucidating gene family evolution and suggests that PYL_EUP genes contribute to the regulation of drought stress responses in EUP, offering valuable genetic resources for functional characterization of PYL genes. Full article

Humulus lupulus L. (hop) is a multipurpose crop valued for its essential role in beer production and for its bioactive compounds with recognized medicinal properties. Otherwise, climate change represents a major challenge to agriculture, particularly impacting the cultivation of crops with stenoecious characteristics, such as hop. This highlights the urgent need to enhance crop resilience to adverse environmental conditions. The phytohormone abscisic acid (ABA) is a key regulator of plant responses to abiotic stress, yet the ABA signaling pathway remains poorly characterized in hop. Harnessing the publicly available hop genomics resources, we identified eight members of the PYRABACTIN RESISTANCE 1 LIKE ABA receptor family (HlPYLs). Phylogenetic and gene structure analyses classified these HlPYLs into the three canonical ABA receptor subfamilies. Furthermore, all eight HlPYLs are likely functional, as suggested by the protein sequence visual analysis. Expression profiling indicates that ABA perception in hop is primarily mediated by the HlPYL1-like and HlPYL8-like subfamilies, while the HlPYL4-like group appears to play a more limited role. Structure modeling and topology predictions of HlPYL1b and HlPYL2 provided insights into their potential functional mechanisms. To assess the physiological relevance of ABA signaling in hop, we evaluated the impact of exogenous ABA application during the ex vitro acclimatization phase. ABA-treated plants exhibited more robust growth, reduced stress symptoms, and improved acclimatization success. These effects were associated with reduced leaf transpiration and enhanced stomatal closure, consistent with ABA-mediated drought tolerance mechanisms. Altogether, this study provides the first comprehensive characterization of ABA receptor components in hop and demonstrates the practical utility of ABA in improving plant performance under ex vitro conditions. These findings lay the groundwork for further functional studies and highlight ABA signaling as a promising target for enhancing stress resilience in hop, with broader implications for sustainable agriculture in the face of climate change. Full article

Background: Protein Phosphatase 2C (PP2C), a conserved family in plants, plays a crucial role in ABA and MAPK signaling pathways. Its functional diversity provides key mechanisms for plants’ adaptation to environmental changes. However, research on PP2C family members remains significantly underexplored in seagrasses, which are model organisms adapted to complex marine environments. Methods: In this study, we systematically analyzed the PP2C gene family in eelgrass using bioinformatic methods and performed a qPCR experiment to verify the expression of a few members in their response to salt stress. Results: The eelgrass PP2C gene family comprises 52 members, categorized into 13 subfamilies. Most PP2C genes exhibit a differential expression across various organs, with some members showing significant organ specificity. For instance, 12 members are specifically highly expressed in male flowers, suggesting that PP2Cs may function in male flower development. Additionally, four members (ZosmaPP2C-04, ZosmaPP2C-07, ZosmaPP2C-15, and ZosmaPP2C-18) in eelgrass are up-regulated under salt stress, with a qPCR confirming their response. The syntenic genes of ZosmaPP2C-15 and ZosmaPP2C-18 were identified across multiple species, indicating their evolutionary conservation. Numerous response elements associated with plant hormones and stress were identified within the promoter sequences of eelgrass PP2C genes. Notably, the promoter regions of salt-responsive genes are rich in the ABRE, implying that ABA may participate in regulating the expression of these PP2Cs. Furthermore, the predictive analysis of protein interactions suggests the potential existence of the ABA core signaling module PYL-PP2C-SnRK2 in eelgrass. Conclusions: This study provides a new insight for understanding the biological functions of the PP2C family in eelgrass, which is important for elucidating the mechanisms of its growth, development, and environmental adaptability. Full article

The MYB family plays a vital role in regulating plant stress resistance. However, the MYB protein in blue honeysuckle remains largely unexplored. In this study, the LcMYB90 gene from blue honeysuckle ‘Lanjingling’ was stably transformed into tobacco and transiently transformed into blue honeysuckle to characterize its function. Subcellular localization analysis revealed that the LcMYB90 protein is localized in the nucleus. Transgenic plants overexpressing LcMYB90 exhibited enhanced growth performance and higher survival rates under drought and salt stress conditions. These plants also showed increased levels of proline and chlorophyll, along with elevated activities of catalase, peroxidase, and superoxide dismutase. Conversely, malondialdehyde content and relative conductivity were lower, indicating that LcMYB90 enhances tolerance to drought and salt stress. Under salt treatment, genes induced by osmotic stress, such as NHX1 (Na⁺/H⁺ antiporters 1) and SOS1 (salt overly sensitive 1), as well as antioxidant defense system genes like SOD (superoxide dismutase) and CAT1 (catalase 1), were more highly induced in overexpression lines compared to the wild type, supporting the hypothesis that LcMYB90 promotes salt tolerance by enhancing osmotic stress resistance and antioxidant capacity. Simultaneously, the transcription levels of genes involved in the abscisic acid pathway, including NCED1/2 (9-cis-epoxycarotenoid dioxygenase 1/2, PYL4/8 (pyrabactin resistance-Like 4/8), and CBL1 (Calcineurin B-like protein 1), were increased under drought stress conditions in the overexpression lines. These results suggest that LcMYB90 maintains cellular homeostasis by promoting the expression of stress-related genes and regulating osmotic and oxidative substances, thereby improving tolerance to drought and salt stress. Full article

The Dof gene family represents a class of plant-specific transcription factors that play crucial regulatory roles in various biological processes, including plant growth, development, and responses to abiotic stress. However, genome-wide identification and functional characterization of the Dof gene family remain unexplored in Dendrobium officinale. In this study, we performed a genome-wide identification and functional analysis of the DoDof gene family. A total of 28 Dof family members were identified and named DoDof1–28 based on genome annotation data. Phylogenetic analysis classified these genes into four major groups (A–D) and further subdivided them into nine subfamilies. Gene structure analysis revealed that most DoDofs lack introns, with no distinct specificity observed among different subfamilies and considerable diversity within the same subfamily. Sequence alignment analysis demonstrated that all DoDof proteins contain a conserved Dof domain consisting of 52 amino acids, which includes a C2-C2 zinc finger motif and a DNA-binding domain. MEME analysis revealed that the conserved motif composition exhibits a certain degree of conservation among DoDof proteins, but significant differences exist across subfamilies. Expression pattern analysis demonstrated that DoDofs have exhibited diverse expression profiles across different developmental stages, tissues, and under abiotic stresses (such as low temperature, salinity, and drought) in D. officinale, suggesting their potential roles in plant development and stress responses. Subcellular localization analysis indicated that DoDof15, DoDof22, and DoDof24 are localized exclusively in the nucleus. Yeast one-hybrid assays revealed that DoDof22 binds to the promoter of the ABA receptor DoPYL9, while DoDof15 and DoDof24 bind to the promoter of the bHLH transcription factor DobHLH68. These results suggest that DoDof proteins may regulate the growth, development, and stress response processes of D. officinale by binding to the promoters of target genes. This study provides critical insights into the functional roles of Dof transcription factors in Orchidaceae family and establishes a theoretical foundation for molecular breeding and stress resistance improvement in D. officinale. Full article