Biotechnology Bulletin ›› 2024, Vol. 40 ›› Issue (12): 145-159.doi: 10.13560/j.cnki.biotech.bull.1985.2024-0151

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Identification and Expression Analysis of MYB Gene Family in Dendrobium catenatum Under the Combined Stress of High Temperature and Drought

TIAN Shan-shan1,2(), HUANG Shi-yu2, YANG Tian-wei1,2, GAO Man-rong1,2, ZHANG Shang-wen2(), HE Long-fei1, ZHANG Xiang-jun2, LI Ting2, SHI Qian2   

  1. 1. Agricultural College, Guangxi University, Nanning 530004
    2. Institute of Biotechnology, Guangxi Academy of Agricultural Sciences, Nanning 530007
  • Received:2024-02-11 Online:2024-12-26 Published:2025-01-15
  • Contact: ZHANG Shang-wen E-mail:2637389679@qq.com;63838114@qq.com

Abstract:

【Objective】To study the structure and function of the transcription factor(TF)family in the Dendrobium catenatum MYB(DcMYB)gene, And identify the prime members and their expression under high-drought stress, which may provide aiding in elucidating D. catenatum's stress adaptation mechanisms.【Method】Utilizing whole-genome transcriptomic data from the combined stress of high temperature & drought, key MYB TFs responsive to this stress were screened, then analyzed, identified via informatics, and their expression patterns under various stresses were validated via real-time PCR.【Result】The 38 DcMYBs genes were identified, they were divided into three types: 1R-MYB, R2R3-MYB, and 3R-MYB, and R2R3-MYB accounted for 89%. The DcMYBs proteins’ lengths were 203-581 aa, they were of good thermal stability, and most of them were of hydrophilic properties. Prediction of subcellular localization revealed that all were present in the nucleus, and some of them coexisted in other organelles. The MEME analysis uncovered that the MYB genes in the same subgroup had similar structural characteristics. DcMYBs was divided into 19 subgroups(D1-D19)after evolution. The prediction for cis-acting element showed that DcMYBs were involved in bio/abiotic stress & hormonal induction, DcMYB6, DcMYB15, DcMYB16, DcMYB21, DcMYB23, and DcMYB35 contained drought-responsive MBS. DcMYB6 and DcMYB35 also harbored 4 ABA-responsive ABREs. Under the combined stress of high temperature and drought, the R2R3-MYB subfamily's genes were significantly induced.The the key genes were consistent with the transcriptome data by RT-qPCR validation. DcMYB6 and DcMYB35 were upregulated under stress, DcMYB15, DcMYB16, DcMYB21, and DcMYB23 were downregulated. Treatment with exogenous abscisic acid, 20% PEG6000, and drought-responsive MBS gene showed an initial rising followed by a declining, suggesting the involvement of six genes in ABA signaling during drought drought. 【Conclusion】Under stress, 38 DcMYBs genes were identified in D. catenatum, dominated by R2R3-MYB type. The encoded proteins are of thermal stability, hydrophilicity, and are predicted to be in nucleus. DcMYBs genes have high homology with Arabidopsis MYB. The specific genes are significantly induced by drought and ABA, and they might be likely involved in biological, abiotic stress, hormone induction, and play important roles in the growth development of D. catenatum under stress environment.

Key words: Dendrobium catenatum, heat and drought, MYB transcription factor, genetic family identification, RT-qPCR validation