Genome-Wide Identification and Comparative Analysis of WRKY Transcription Factors Related to Momilactone Biosynthesis in Calohypnum plumiforme

Yao Wang,Guoyin Kai,Ruiyan Zhu,Siwei Zhang,Min Shi,Qikai Huang,Shuiliang Guo

doi:10.3389/fevo.2021.809729

Abstract

Momilactones are diterpenoid phytoalexins with allelopathic functions, which have been found in the widely distributed bryophyte Calohypnum plumiforme. Clustered genes containing CpDTC1/HpDTC1, CpCYP970A14, CpCYP964A1, and CpMAS are involved in momilactone biosynthesis. Besides, momilactone concentration in C. plumiforme is affected by heavy metal treatment such as CuCl2. However, transcription factors which might regulate momilactone biosynthesis are unclear. WRKY transcription factors (TFs) regulate phytoalexin biosynthesis in many plant species. In this study, a systematic analysis of the WRKY TFs was performed according to the C. plumiforme genome. A total of 19 CpWRKY genes were identified and categorized into five subgroups based on their phylogenetic relationship. Conserved domain and motif analysis suggested that the WRKY domain was highly conserved, but there were some variations. Cis-acting elements and binding sites analysis implied that CpWRKY genes might be induced by stress and further regulate the biosynthesis of momilactones. Our study lays a foundation for further functional characterization of the candidate CpWRKY genes involved in the regulation of momilactone biosynthesis, and provides new strategies for increasing momilactone production.

Highlights

Calohypnum plumiforme is a widely distributed bryophyte in East Asia, which has been broadly used as a bio monitor to trace metals in the atmosphere (Okada et al, 2016; Li et al, 2020)
Momilactone A and B were firstly found in the cultivated rice Oryza sativa, exhibiting remarkable antimicrobial and allelopathic functions (Kato-Noguchi et al, 2010; Toyomasu et al, 2014; Mao et al, 2020), which are biosynthesized through the biosynthetic gene clusters (BGCs) (Kato et al, 1973; Nützmann et al, 2018)
This study provides available data to reveal the biological function of CpWRKY proteins, and lays a theoretical foundation for the discovery of potential CpWRKY proteins that regulates the biosynthesis of momilactones

Summary

Introduction

Calohypnum plumiforme (formerly Hypnum plumaeforme) is a widely distributed bryophyte in East Asia, which has been broadly used as a bio monitor to trace metals in the atmosphere (Okada et al, 2016; Li et al, 2020). WRKY in Calohypnum plumiforme defense compound momilactones (Kato-Noguchi and Kobayashi, 2009; Okada et al, 2016; Mao et al, 2020). The C. plumiforme genome was sequenced and annotated, with a genome size of 335 Mb (Mao et al, 2020). Genome sequencing revealed a functional BGC responsible for momilactone biosynthesis in C. plumiforme (Mao et al, 2020)

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Results

Conclusion