The spatiotemporal profile of Dendrobium huoshanense and functional identification of bHLH genes under exogenous MeJA using comparative transcriptomics and genomics

Frontiers in Plant Science

Plant Science

Cunwu Chen¹  Guohui Li¹  Cheng Song¹  Jun Dai¹  Yan Wang¹  Xiaomei He¹  Fucheng Zhu¹  Chunyan Jiao²  Irfan Ali Sabir³  Yingyu Zhang⁴  Longyun Liu⁵  Wenwu Zhang⁶ 

[1] Anhui Engineering Laboratory for Conservation and Sustainable Utilization of Traditional Chinese Medicine Resources, Anhui Engineering Research Center for Eco-agriculture of Traditional Chinese Medicine, College of Biological and Pharmaceutical Engineering, West Anhui University, Lu’an, China;College of Life Sciences, Hefei Normal University, Hefei, China;Department of Plant Science, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China;Henan Key Laboratory of Rare Diseases, Endocrinology and Metabolism Center, The First Affiliated Hospital, and College of Clinical Medicine of Henan University of Science and Technology, Luoyang, China;School of Bioengineering, Hefei Technology College, Hefei, China;School of Life Science, Anhui Agricultural University, Hefei, China;

关键词: Dendrobium huoshanense;    bHLH transcription factor;    JA signaling;    abiotic stress;    genomics;   

DOI  :  10.3389/fpls.2023.1169386

 received in 2023-02-19, accepted in 2023-04-17,  发布年份 2023

来源: Frontiers

【 摘 要 】

IntroductionAlkaloids are one of the main medicinal components of Dendrobium species. Dendrobium alkaloids are mainly composed of terpene alkaloids. Jasmonic acid (JA) induce the biosynthesis of such alkaloids, mainly by enhancing the expression of JA-responsive genes to increase plant resistance and increase the content of alkaloids. Many JA-responsive genes are the target genes of bHLH transcription factors (TFs), especially the MYC2 transcription factor.MethodsIn this study, the differentially expressed genes involved in the JA signaling pathway were screened out from Dendrobium huoshanense using comparative transcriptomics approaches, revealing the critical roles of basic helix-loop-helix (bHLH) family, particularly the MYC2 subfamily.Results and discussionMicrosynteny-based comparative genomics demonstrated that whole genome duplication (WGD) and segmental duplication events drove bHLH genes expansion and functional divergence. Tandem duplication accelerated the generation of bHLH paralogs. Multiple sequence alignments showed that all bHLH proteins included bHLH-zip and ACT-like conserved domains. The MYC2 subfamily had a typical bHLH-MYC_N domain. The phylogenetic tree revealed the classification and putative roles of bHLHs. The analysis of cis-acting elements revealed that promoter of the majority of bHLH genes contain multiple regulatory elements relevant to light response, hormone responses, and abiotic stresses, and the bHLH genes could be activated by binding these elements. The expression profiling and qRT-PCR results indicated that bHLH subgroups IIIe and IIId may have an antagonistic role in JA-mediated expression of stress-related genes. DhbHLH20 and DhbHLH21 were considered to be the positive regulators in the early response of JA signaling, while DhbHLH24 and DhbHLH25 might be the negative regulators. Our findings may provide a practical reference for the functional study of DhbHLH genes and the regulation of secondary metabolites.

【 授权许可】

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Copyright © 2023 He, Zhang, Sabir, Jiao, Li, Wang, Zhu, Dai, Liu, Chen, Zhang and Song