Genome-wide identification and expression profiling reveal the regulatory role of U-box E3 ubiquitin ligase genes in strawberry fruit ripening and abiotic stresses resistance

Leiyu Jiang; Yuanxiu Lin; Liangxin Wang; Yuting Peng; Min Yang; Yuyan Jiang; Guoyan Hou; Xiaoyang Liu; Mengyao Li; Yunting Zhang; Yong Zhang; Qing Chen; Yan Wang; Wen He; Xiaorong Wang; Haoru Tang; Ya Luo

doi:10.3389/fpls.2023.1171056

Genome-wide identification and expression profiling reveal the regulatory role of U-box E3 ubiquitin ligase genes in strawberry fruit ripening and abiotic stresses resistance

Front Plant Sci. 2023 Mar 23:14:1171056. doi: 10.3389/fpls.2023.1171056. eCollection 2023.

Authors

Leiyu Jiang¹, Yuanxiu Lin^{1

2}, Liangxin Wang¹, Yuting Peng¹, Min Yang¹, Yuyan Jiang¹, Guoyan Hou¹, Xiaoyang Liu¹, Mengyao Li¹, Yunting Zhang^{1

2}, Yong Zhang¹, Qing Chen¹, Yan Wang^{1

2}, Wen He^{1

2}, Xiaorong Wang^{1

2}, Haoru Tang^{1

2}, Ya Luo¹

Affiliations

¹ College of Horticulture, Sichuan Agricultural University, Chengdu, China.
² Institute of Pomology & Olericulture, Sichuan Agricultural University, Chengdu, China.

Abstract

The plant U-box (PUB) proteins are a type of E3 ubiquitin ligases well known for their functions in response to various stresses. They are also related to fruit development and ripening. However, PUB members possess such roles that remain unclear in strawberry. In this study, 155 PUB genes were identified in octoploid strawberry and classified into four groups. Their promoters possessed a variety of cis-acting elements, most of which are associated with abiotic stresses, followed by phytohormones response and development. Protein-protein interaction analysis suggested that FaU-box members could interact with each other as well as other proteins involved in hormone signaling and stress resistance. Transcriptome-based and RT-qPCR expression analysis revealed the potential involvement of FaU-box genes in resistance to stresses and fruit ripening. Of these, FaU-box98 and FaU-box136 were positively while FaU-box52 was negatively related to strawberry ripening. FaU-box98 comprehensively participated in resistance of ABA, cold, and salt, while FaU-box83 and FaU-box136 were broadly associated with drought and salt stresses. FaU-box18 and FaU-box52 were ABA-specific; FaU-box3 was specific to salt stress. In addition, the functional analysis of a randomly selected FaU-box (FaU-box127) showed that the transient overexpression of FaU-box127 promoted the ripening of strawberry fruit, along with significant changes in the expression levels of some ripening-related genes and the content of organic acid and soluble sugar. Overall, these findings provided comprehensive information about the FaU-box gene family and identified the potential FaU-box members participating in stress resistance and strawberry fruit ripening regulation.

Keywords: U-box ubiquitin ligases; fruit ripening; gene function; strawberry; stresses resistance.

Grants and funding

This research was funded by the National Natural Science Foundation of China (32272688); Sweet potato and Leguminosae Germplasm Innovation and Utilization Key Laboratory of Sichuan Province (2021CGIHL05), and the Specialty Construction Program of Sichuan Agricultural University.