Apyrases (APYs), nucleoside triphosphate-diphosphohydrolases, serve as critical enzymes in regulating extracellular ATP levels and maintaining biochemical homeostasis under stress conditions. Under the escalating pressures of global climate change, the adverse effects of rising temperatures and altered precipitation patterns on crop productivity have become increasingly severe. Chinese cabbage (Brassica rapa L. ssp. pekinensis, B.rapa), a globally significant cruciferous crop, faces substantial threats due to its high sensitivity to environmental stressors. Throughout its growth cycle, it is frequently subjected to various environmental stresses and exhibits high sensitivity to drought stress and temperature fluctuations. In this study, we systematically identified 13 APY genes in the B.rapa genome and conducted a comprehensive analysis of their phylogenetic relationships, conserved motifs, and cis-regulatory elements. qRT-PCR analysis further revealed distinct tissue-specific expression patterns of BrAPYs and their differential regulation under drought, extreme temperature, and cold stress conditions. These findings establish a molecular framework for understanding the stress-responsive functions of APYs in Chinese cabbage and highlight potential targets for enhancing stress tolerance through genetic improvement.
Yang Zhou, Jiangtao Du, Shanyu Li et al.· Frontiers in Plant Science· 0 citations
Leafy head formation is a critical agronomic trait that determines the yield and quality of Chinese cabbage (Brassica rapa), involving complex morphological transitions. While BEL1-like homeodomain (BLH) transcription factors regulate development, their specific roles in heading remain elusive. To systematically identify the BraBLH gene family and elucidate its expression networks and regulatory functions during leafy head formation, a total of 36 BraBLH genes were identified. The phylogenetic analysis revealed that Brassica rapa had a specific clade (Group II). A high-resolution spatiotemporal expression framework for the BraBLH family was constructed. Subsequently, comparative transcriptomics of heading, non-heading, and GA3-treated heading plants highlighted multiple differentially expressed BraBLH genes, suggesting that this gene family may contribute to the regulation of leafy head formation in Chinese cabbage. Subsequently, a high-resolution spatiotemporal expression framework for the BraBLH family was constructed. Within this framework, BraBLH5 emerged as a pivotal node integrating GA signaling, peaking during the rosette stage to initiate heading. In contrast, a distinct negative module (BraBLH9/26) was significantly upregulated in the non-heading line. Spatial profiling further revealed functional compartmentalization within the family, where specific members maintained shoot apical meristem identity, whereas others drove inner leaf expansion and incurvature. Furthermore, subcellular localization analysis confirmed that BraBLH5 was localized to the nucleus. Ultimately, this systems-level study elucidates a transcriptome-driven framework for heading, highlighting a GA-mediated BraBLH5 mechanism and providing valuable candidates for Brassica functional genomics.