Physiological and Transcriptomic Analyses Reveal the Response of Medicinal Plant Bletilla striata (Thunb. ex A. Murray) Rchb. f. via Regulating Genes Involved in the ABA Signaling Pathway, Photosynthesis, and ROS Scavenging under Drought Stress

Bletilla striata is a valuable Chinese herbal medicinal plant widely used in various fields. To meet the market demand for this herb, tissue culture technology of B. was developed. However, drought stress has been significant threat to survival cultivated striata. further understand underlying mechanisms under stress, its response investigated at physiological and transcriptional levels. Our photosynthesis results show that decline net rate (Pn) leaves mainly caused by nonstomatal limitation factors. Using transcriptomic analysis 2398, differentially expressed genes (DEGs) were identified. KEGG enrichment showed DEGs involved hormone signal transduction (ko04075) significantly altered, especially abscisic-acid signaling pathway. The up-regulations serine/threonine protein kinase (SnRK2) S-type anion (SLAH2) channels might lead stomatal closure, which reason photosynthesis. Moreover, downregulation cytochrome b6 photosystem I reaction center subunit III/IV be major limitation. In addition, enhanced ability ROS scavenging via activating gene expression superoxide dismutase, catalase, peroxidase stress. study understanding