Genome-Wide Identification and Expression Analysis of JAZ Family Involved in Hormone and Abiotic Stress in Sweet Potato and Its Two Diploid Relatives

Zhengwei Huang,Zhen Wang,Huan Zhang,Hong Zhai,Xu Li,Shaozhen He,Ning Zhao,Shaopei Gao,Qingchang Liu

doi:10.3390/ijms22189786

Abstract

Jasmonate ZIM-domain (JAZ) proteins are key repressors of a jasmonic acid signaling pathway. They play essential roles in the regulation of plant growth and development, as well as environmental stress responses. However, this gene family has not been explored in sweet potato. In this study, we identified 14, 15, and 14 JAZs in cultivated hexaploid sweet potato (Ipomoea batatas, 2n = 6x = 90), and its two diploid relatives Ipomoea trifida (2n = 2x = 30) and Ipomoea triloba (2n = 2x = 30), respectively. These JAZs were divided into five subgroups according to their phylogenetic relationships with Arabidopsis. The protein physiological properties, chromosome localization, phylogenetic relationship, gene structure, promoter cis-elements, protein interaction network, and expression pattern of these 43 JAZs were systematically investigated. The results suggested that there was a differentiation between homologous JAZs, and each JAZ gene played different vital roles in growth and development, hormone crosstalk, and abiotic stress response between sweet potato and its two diploid relatives. Our work provided comprehensive comparison and understanding of the JAZ genes in sweet potato and its two diploid relatives, supplied a theoretical foundation for their functional study, and further facilitated the molecular breeding of sweet potato.

Highlights

Jasmonic acid (JA) plays a central role in plant growth, developmental processes, and plant response to biotic and abiotic stresses [1,2,3,4]
In the absence of JA-Ile, the bioactive form of JA, jasmonate–ZIM domain (JAZ) proteins act as repressors of the transcription factors; the presence of JA-Ile promotes the interaction between CORONATINE INSENSITIVE 1 (COI1) and JAZ proteins, and the JAZ proteins are subsequently ubiquitinated by SCFCOI1 and degraded through the 26S proteasome pathway
The tissue specificity and expression pattern analysis for hormone response and abiotic stress of JAZs were analyzed by qRT-PCR and RNA-seq

Summary

Introduction

Jasmonic acid (JA) plays a central role in plant growth, developmental processes, and plant response to biotic and abiotic stresses [1,2,3,4]. The crosstalks among JA and other plant hormones regulate the balance between plant growth and defense [5,6,7]. The core JA signaling module consists of the JA receptor CORONATINE INSENSITIVE 1 (COI1), which interacts with multiple proteins to form the SCFCOI1 E3 ubiquitin ligase complex, a subset of jasmonate–ZIM domain (JAZ) repressor proteins, and the various transcription factors such as MYC2 involved in regulating the expression of JA-responsive genes. In the absence of JA-Ile, the bioactive form of JA, JAZ proteins act as repressors of the transcription factors; the presence of JA-Ile promotes the interaction between COI1 and JAZ proteins, and the JAZ proteins are subsequently ubiquitinated by SCFCOI1 and degraded through the 26S proteasome pathway. The JAZ repressor is critical in the signaling cascades triggered by jasmonates

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Conclusion