Basic Pentacysteine (BPC) represents a class of plant-exclusive transcription factors, serving pivotal roles in orchestrating developmental processes and mediating responses to both biotic and abiotic stressors. However, the genome-wide characteristics and low-temperature response mechanism of the BPC gene family in cotton remain unclear. Employing a genome-wide screening approach, this study characterized 60 distinct BPC transcription factor genes across ten Gossypium species. Conserved structural analysis showed that all BPC members carried a highly conserved GAGA-binding domain. Concurrently, the exploration of cis-acting elements within promoter regions demonstrated the potential involvement of these BPC transcription factors in modulating developmental processes, hormone signaling cascades, and abiotic stress adaptation mechanisms. Genomic collinearity analysis shows that segmental duplication is the core mechanism for the expansion of this gene family. Expression analysis indicated that the transcription level of GhBPC4 was significantly increased under low-temperature stress. Genetic function studies displayed that VIGS-mediated GhBPC4 silencing reduced cotton cold tolerance. This study systematically analyzed the genomic characteristics of the cotton BPC transcription factor family and functionally validated the molecular mechanism of GhBPC4-mediated cryogenic response. These findings establish an important foundation for subsequent analysis of multidimensional regulatory networks and the breeding of cold-resistant cotton germplasms.

This research centers on the sand-fixing plant known as Stipagrostis pennata, from which the β-glucosidase gene SpBGLU25 was successfully cloned using the molecular cloning method. SpBGLU25 encodes a hydrophilic and stable protein made up of 193 amino acids, located in the cell membrane. qRT-PCR analysis indicated that the expression of the SpBGLU25 is closely linked to the drought stress tolerance of S. pennata. Following this, functional validation was performed using an Arabidopsis overexpression system. The overexpression of transgenic Arabidopsis lines showed significantly improved drought tolerance under PEG and mannitol treatments. Assessments of germination, root length, and physiological indicators such as proline, malondialdehyde content, soluble sugars, and relative leaf water content (RLWC) further confirmed the enhanced performance of the overexpressing plants. Additionally, the comparative transcriptomic analysis of SpBGLU25-OE Arabidopsis compared to the wild-type (WT) showed that differentially upregulated genes were primarily enriched in categories of “cellular process,” “cell,” and “catalytic activity.” KEGG pathway enrichment analysis indicated that the genes were mainly concentrated in the pathways of phenylpropanoid biosynthesis and plant hormone signal transduction. These findings provide a crucial foundation for further investigation into the function of the SpBGLU25 and its role in regulating plant tissue development and adaptation to stress. This research is anticipated to offer new theoretical insights and genetic resources for enhancing plant stress tolerance through genetic engineering.

Background: The TGACG-BINDING FACTORS (TGA) gene family, a key subgroup of bZIP transcription factors, mediates plant stress responses and developmental processes by binding to the as-1 cis-element in target gene promoters to regulate transcriptional activation or repression. Despite its functional significance, systematic characterization of TGA genes in cotton (Gossypium spp.) remains insufficient. Methods: In this study, we performed a comprehensive genome-wide identification and phylogenetic analysis of TGA members across 10 Gossypium species and verified the functions of candidate genes using VIGS technology. Results: A total of 74 TGA homologous genes with conserved DOG1 and bZIP domains were identified. Evolutionary analysis revealed that the cotton TGA gene family can be classified into five distinct branches, suggesting functional diversification. Functional prediction analyses indicated these genes in cotton growth regulation and stress adaptation, potentially through hormone-mediated signaling pathways. Expression profiling demonstrated both tissue-specific expression patterns and salt-stress responsiveness in Gossypium hirsutum TGA genes, and GhTGA2 exhibited the most significant up-regulated expression under salt stress. Virus-induced gene silencing (VIGS)-mediated GhTGA2 silencing significantly reduced the salt tolerance in cotton. Conclusions: The TGA gene family is involved in regulating cotton growth, development, and stress responses, and plays a critical role in mediating salt stress tolerance in cotton. Our results provide mechanistic insights into cotton stress adaptation and establish a valuable genetic resource for developing elite salt-tolerant cotton cultivars, with direct implications for sustainable cotton production.

The SNAC (Stress-responsive NAC) subfamily, a key branch of the conserved NAC transcription factor family, plays a central role in regulating plant stress response. However, systematic characterization of the SNAC family in cotton (Gossypium spp.) remains unclear. Employing a genome-wide screening approach, this study characterized 75 distinct SNAC transcription factor genes across ten Gossypium species, with tetraploid cottons harboring twice as many as their diploid progenitors. Phylogenetic analysis categorized the genes into three subgroups, with members of the same subgroup exhibiting conserved motif compositions and gene structures. Chromosomal localization revealed a conserved distribution pattern of SNAC genes between the Dt and At subgenomes in tetraploid cotton. Genomic collinearity analysis suggested that the primary driver of SNAC family expansion was segmental duplication. Promoter analysis predicted 2974 cis-regulatory elements, including cold- and hormone-responsive motifs, indicating their potential involvement in stress regulation. These GhSNAC genes indicated significant induced expressions under stress conditions, and GhSNAC3D exhibited the most significant up-regulated expression under low temperature stress. Genetic function studies displayed that VIGS-mediated GhSNAC3D-silencing significantly reduced the cold tolerance in cotton. This study systematically analyzed the genomic characteristics of the cotton SNAC family and functionally validated the molecular mechanism of GhSNAC3D-mediated cryogenic response, which lays a foundation for subsequent research on cold resistance in cotton and stress-resistant breeding.

Cotton’s susceptibility to low temperatures makes it a crucial raw resource for the world’s textile industry, yet its cultivation in temperate regions is severely limited. Although plant growth and stress responses depend on receptor-like kinases (RLKs), the functions of the MEDOS (MDS) gene family, which includes genes that encode RLK, are still poorly understood in cotton. In this study, we conducted a genome-wide analysis to systematically investigate the distribution of MDS gene family members in four cotton species. Phylogenetic analysis identified five evolutionary clades of the MDS gene family in cotton. The role of promoter cis-acting elements in hormone signaling and abiotic stress responses was suggested by analysis. Collinearity analysis demonstrated that segmental duplication was the primary driver of family expansion. Gene expression profiling showed that GhMDS11 was significantly upregulated under cold stress. Functional validation through silencing GhMDS11 compromised cold tolerance, confirming its role in stress adaptation. Comparative transcriptome study of silenced plants demonstrated substantial enrichment in pathways associated with hormone signal transduction and fatty acid breakdown. It is speculated that the chain of “hormone synthesis → signal transduction → secondary metabolism” completely presents the transcriptional regulation network and functional response of plants after receptor kinase VIGS. Silencing the GhMDS11 gene in cotton initiates regulatory effects through hormone synthesis, which is amplified via a signal transduction cascade, ultimately affecting secondary metabolism. This comprehensive pathway clearly demonstrates the downstream transcriptional reprogramming and functional changes. This work thoroughly examined the evolutionary traits of the MDS family across four cotton species and clarified the functional and molecular processes of GhMDS11 in improving low-temperature tolerance, laying a solid foundation for further clarifying multidimensional regulatory networks and breeding cold-resistant cotton materials. Simultaneously, our findings pave the way for future research to develop molecular markers, which could potentially shorten the breeding cycle and facilitate the targeted enhancement of cold tolerance in cotton.

Lipid transfer proteins (LTPs) play crucial regulatory roles in plant growth, development, and abiotic stress responses. Stipagrostis pennata is a species of grass widely distributed in arid and semi-arid regions, particularly adapted to desert and steppe environments. Under extreme drought conditions, it exhibits a variety of physiological and morphological adaptation mechanisms, making it an important species for studying plant drought tolerance. Recently, LTPs have been found to exhibit upregulated expression under drought stress in plants such as wheat and tobacco, enhancing their drought tolerance. However, the functional role of LTPs in S. pennata remains unexplored. In this study, the SpLTP1 gene was isolated from S. pennata via molecular cloning, encoding a 116-amino acid protein. Phylogenetic analysis revealed that this protein contains a highly conserved nsLTP1 (cd01960) domain and has high sequence similarity with LTPs of Setaria viridis, Setaria italica, Musa acuminata and Phragmites australis. qRT-PCR revealed that SpLTP1 was highly expressed and dynamically regulated under drought, suggesting its potential role in root rhizosheath formation and drought tolerance. To investigate SpLTP1 function, SpLTP1-overexpressing (SpLTP1-OE) and complementation (SpLTP1-atltp) Arabidopsis lines were generated using the floral dip method, in comparison with the existing wild-type (WT) and the LTP-deficient mutant (atltp). Drought stress phenotyping and physiological assays indicated that SpLTP1 likely enhances drought tolerance by elevating antioxidant enzyme activities and osmolyte accumulation. Comparative transcriptome analysis of SpLTP1-OE and WT plants further suggested that SpLTP1 modulates critical pathways, including phenylpropanoid biosynthesis, zeatin biosynthesis, and plant hormone signal transduction, thereby influencing plant growth and stress adaptation. These findings not only provide novel insights into the molecular mechanisms by which SpLTP1 regulates rhizosheath development in S. pennata but also establish a foundation for deciphering its role in extreme drought adaptation.