Genome-wide identification of myeloblastosis gene family and its response to cadmium stress in Ipomoea aquatica

Zheng Liu; Yuxin Zhang; Muhammad Ahsan Altaf; Yuanyuan Hao; Guangzhen Zhou; Xinyu Li; Jie Zhu; Wuqiang Ma; Zhiwei Wang; Wenlong Bao

doi:10.3389/fpls.2022.979988

Genome-wide identification of myeloblastosis gene family and its response to cadmium stress in Ipomoea aquatica

Front Plant Sci. 2022 Aug 23:13:979988. doi: 10.3389/fpls.2022.979988. eCollection 2022.

Authors

Zheng Liu¹, Yuxin Zhang¹, Muhammad Ahsan Altaf¹, Yuanyuan Hao¹, Guangzhen Zhou², Xinyu Li², Jie Zhu¹, Wuqiang Ma¹, Zhiwei Wang^{1

3}, Wenlong Bao¹

Affiliations

¹ Key Laboratory for Quality Regulation of Tropical Horticultural Crops of Hainan Province, College of Horticulture, Hainan University, Haikou, China.
² College of Tropical Crops, Hainan University, Haikou, China.
³ Hainan Yazhou Bay Seed Laboratory, Sanya Nanfan Research Institute of Hainan University, Sanya, China.

Abstract

The myeloblastosis (MYB) proteins perform key functions in mediating cadmium (Cd) tolerance of plants. Ipomoea aquatica has strong adaptability to Cd Stress, while the roles of the I. aquatica MYB gene family with respect to Cd stress are still unclear. Here, we identified a total of 183 MYB genes in the I. aquatica genome (laMYB), which were classified into 66 1R-type IaMYB, 112 2R-type IaMYB, four 3R-type IaMYB, and one 4R-type IaMYB based on the number of the MYB repeat in each gene. The analysis of phylogenetic tree indicated that most of IaMYB genes are associated with the diverse biological processes including defense, development and metabolism. Analysis of sequence features showed that the IaMYB genes within identical subfamily have the similar patterns of the motif distributions and gene structures. Analysis of gene duplication events revealed that the dispersed duplication (DSD) and whole-genome duplication (WGD) modes play vital roles in the expansion of the IaMYB gene family. Expression profiling manifests that approximately 20% of IaMYB genes had significant role in the roots of I. aquatica under Cd stress. Promoter profiling implied that the differentially expressed genes might be induced by environmental factors or inherent hormones and thereby execute their function in Cd response. Remarkably, the 2R-type IaMYB157 with abundant light-responsive element G-box and ABA-responsive element ABRE in its promoter region exhibited very strong response to Cd stress. Taken together, our findings provide an important candidate IaMYB gene for further deciphering the molecular regulatory mechanism in plant with respect to Cd stress.

Keywords: cis-acting element; gene duplication mode; gene expression; heavy metal stress; transcription factor.