Browse Articles

Article|23 Mar 2022|OPEN
The genome of Hibiscus hamabo reveals its adaptation to saline and waterlogged habitat
Zhiquan Wang1 ,† , Jia-Yu Xue2 ,† , Shuai-Ya Hu2 ,† , Fengjiao Zhang1 , Ranran Yu3 , Dijun Chen3 , Yves Van de Peer2,4,5 , Jiafu Jiang6 , Aiping Song6 , Longjie Ni7 , Jianfeng Hua1 and Zhiguo Lu1 , Yunlong Yin1 , Chunsun Gu,1,7,8 ,
1Institute of Botany, Jiangsu Province and Chinese Academy of Sciences, Nanjing, 210014, China
2College of Horticulture, Academy for Advanced Interdisciplinary Studies, Nanjing Agricultural University, Nanjing 210095, China
3State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing 210023, China
4Department of Plant Biotechnology and Bioinformatics, Ghent University, VIB-UGent Center for Plant Systems Biology, B-9052 Ghent, Belgium
5Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria 0028, South Africa
6College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China
7College of Forest Sciences, Nanjing Forestry University, Nanjing, 210037, China
8Jiangsu Key Laboratory for the Research and Utilization of Plant Resources, Jiangsu Utilization of Agricultural Germplasm, Nanjing, 210014, China
*Corresponding author. E-mail: chunsungu@cnbg.net
Zhiquan Wang,Jia-Yu Xue and Shuai-Ya Hu contributed equally to the study.

Horticulture Research 9,
Article number: uhac067 (2022)
doi: https://doi.org/10.1093/hr/uhac067
Views: 36

Received: 26 Oct 2021
Accepted: 09 Mar 2022
Published online: 23 Mar 2022

Abstract

Hibiscus hamabo is a semi-mangrove species with strong tolerance to salt and waterlogging stress. However, the molecular basis and mechanisms that underlie this strong adaptability to harsh environments remain poorly understood. Here, we assembled a high-quality, chromosome-level genome of this semi-mangrove plant and analyzed its transcriptome under different stress treatments to reveal regulatory responses and mechanisms. Our analyses suggested that H. hamabo has undergone two recent successive polyploidy events, a whole-genome duplication followed by a whole-genome triplication, resulting in an unusually large gene number (107 309 genes). Comparison of the H. hamabo genome with that of its close relative Hibiscus cannabinus, which has not experienced a recent WGT, indicated that genes associated with high stress resistance have been preferentially preserved in the H. hamabo genome, suggesting an underlying association between polyploidy and stronger stress resistance. Transcriptomic data indicated that genes in the roots and leaves responded differently to stress. In roots, genes that regulate ion channels involved in biosynthetic and metabolic processes responded quickly to adjust the ion concentration and provide metabolic products to protect root cells, whereas no such rapid response was observed from genes in leaves. Using co-expression networks, potential stress resistance genes were identified for use in future functional investigations. The genome sequence, along with several transcriptome datasets, provide insights into genome evolution and the mechanism of salt and waterlogging tolerance in H. hamabo, suggesting the importance of polyploidization for environmental adaptation.