Introduction: Areca catechu is a widely cultivated palm species with significant economic and medicinal value. However, A. catechu is a tropical plant that is particularly susceptible to low temperatures.Methods: This study integrates physiological profiling with transcriptomic sequencing to systematically investigate the cold-response mechanisms of A. catechu.Results: Multivariate variance analysis revealed that peroxidase (POD) activity and chlorophyll content are significant biomarkers strongly correlated with cold tolerance. A comprehensive investigation into the temporal expression of genes in response to 24 hours of cold stress was conducted, using RNA-seq analysis. This analysis yielded a substantial number of differentially expressed genes (DEGs), amounting to 20,870, which were found to be subject to temporal regulation. KEGG pathway enrichment analysis revealed substantial activation in three metabolic pathways: phytohormone signaling, alkaloid biosynthesis (tropane/piperidine/pyridine), and flavonoid biosynthesis. The application of Weighted Gene Co-expression Network Analysis (WGCNA), in conjunction with a dynamic tree-cutting algorithm, resulted in the identification of 25 co-expression modules. Eigenvector centrality analysis identified six hub genes responsive to cold stress: ZMYND15, ABHD17B, ATL8, WNK5, XTH3 and TPS. The findings of this study delineate three key aspects: (1) temporal dynamics of cold-responsive physiological processes, (2) pathway-level characterization of DEG enrichment patterns, and (3) genetic determinants underlying cold stress adaptation.Discussion: These findings clarify the time series and core physiological indicators of A. catechu during various physiological processes, identify pivotal genes associated with cold stress, and provide a gene-to-phenotype framework for optimizing cold-resilient cultivation protocols and molecular marker-assisted breeding strategies.
Lumnitzera littorea (Jack) Voigt is an endangered mangrove species in China. Low fecundity and environmental pressure are supposed to be key factors limiting the population expansion of L. littorea. Transcription factors with the MADS-box domain are crucial regulators of plant flower development, reproduction, and stress response. In this study, we performed a comprehensive investigation into the features and functions of MADS-box genes of L. littorea. Sixty-three LlMADS genes with similar structure and motif composition were identified in the L. littorea genome, and these genes were unevenly distributed on the 11 chromosomes. Segmental duplication was suggested to make a main contribution to the expansion of the LlMADS gene family. Some LIMADS genes exhibited differential expression in different flower types or in response to cold stress. Overexpression of the B-class gene LlMADS37 had substantial effects on the flower morphology and flowering time of transgenic Arabidopsis plants, demonstrating its key role in regulating flower morphogenesis and inflorescence. These findings largely enrich our understanding of the functional importance of MADS-box genes in the inflorescence and stress acclimation of L. littorea and provide valuable resources for future genetic research to improve the conservation of this species.
Inflorescence degeneration in Areca catechu L. is characterized by growth arrest, tissue shrinkage and browning, ultimately compromising functional inflorescence formation and yield stability. To investigate its developmental window and regulatory basis, inflorescences from different leaf positions at the full-bloom stage were analyzed using anatomical observation, morphological measurements, carbohydrate and hormone assays, and RNA-seq-based transcriptomic analysis with qRT-PCR validation. Inflorescence degeneration was mainly concentrated in axillary inflorescences at the third and fourth leaf positions (BY3 and BY4). Compared with adjacent normal inflorescences, degenerated inflorescences showed reduced sucrose, starch and trehalose contents, increased ABA, JA and MeJA levels, and decreased cZR levels. Transcriptomic analysis revealed clear separation between degenerated and normal inflorescences, and differentially expressed genes were enriched in starch and sucrose metabolism, plant hormone signal transduction and transcriptional regulation. Co-expression network analysis identified modules associated with the degeneration window and key physiological traits, highlighting six candidate hub genes: AcAHP2, AcTIFY4B, AcTPS9-2, AcHXK2, AcWRKY3 and AcMPK1. These findings suggest that inflorescence degeneration is closely associated with carbon metabolic imbalance, hormone network remodeling and co-expression network reprogramming within a specific developmental window, providing a basis for future mechanistic studies and control strategies.
Jasmonate ZIM-domain (JAZ) proteins play a pivotal role in mediating plant growth, development, and responses to both biotic and abiotic stresses. However, our knowledge about the JAZ family genes in Areca catechu remains limited. This study conducted a genome-wide screening and analysis of JAZ genes in A. catechu to investigate their biochemical characteristics, gene structure features, phylogenetic relationships, and expression profiles in different organs. A total of 14 JAZ genes (AcJAZs) were detected in the A. catechu genome, all containing an N-terminal TIFY domain and a C-terminal Jas domain. Phylogenetic analysis categorized these AcJAZs into five subfamilies according to their similarities in protein sequences. Quantitative real-time reverse transcription PCR (qRT-PCR) experiments demonstrated the ample expression specificity of these AcJAZ genes across different organs and flower development stages. More importantly, most AcJAZ genes are expressed significantly higher in blooming male flowers than female flowers, suggesting that they may participate in regulating the difference between male and female flowers of A. catechu. This study elucidates the genomic features and functions of JAZ genes in A. catechu, providing new insights into the mechanisms underlying the development and differentiation of unisexual flowers in A. catechu.