Genome-wide transcriptional profiling for elucidating the effects of brassinosteroids on Glycine max during early vegetative development

Li Song,Qiuming Yao,Wei Chen,Binhui Guo,Henry T Nguyen,Babu Valliyodan,Zhiyong Wang

doi:10.1038/s41598-019-52599-3

Li Song, Qiuming Yao + Show 5 more

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https://doi.org/10.1038/s41598-019-52599-3

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Abstract

Soybean is a widely grown grain legume and one of the most important economic crop species. Brassinosteroids play a crucial role in plant vegetative growth and reproductive development. However, it remains unclear how BRs regulate the developmental processes in soybean, and the molecular mechanism underlying soybean early development is largely unexplored. In this study, we first characterized how soybean early vegetative growth was specifically regulated by the BR biosynthesis inhibitor propiconazole; this characterization included shortened root and shoot lengths, reduced leaf area, and decreased chlorophyll content. In addition, the growth inhibition induced by Pcz could be rescued by exogenous brassinolide application. The RNA-seq technique was employed to investigate the BR regulatory networks during soybean early vegetative development. Identification and analysis of differentially expressed genes indicated that BRs orchestrate a wide range of cellular activities and biological processes in soybean under various BR concentrations. The regulatory networks between BRs and multiple hormones or stress-related pathways were investigated. The results provide a comprehensive view of the physiological functions of BRs and new insights into the molecular mechanisms at the transcriptional level of BR regulation of soybean early development.

Highlights

Soybean is a widely grown grain legume and one of the most important economic crop species
To investigate whether and how BR biosynthesis affects soybean growth, the morphological phenotypes of Williams 82 soybean seedlings treated with three different concentrations of Pcz for 10 days were evaluated
The growth defects, including those in plant height, shoot length, petiole length and leaf area, could be partially rescued by adding exogenous BL at different concentrations (Fig. S1C–F). These results suggest that BR synthesis regulates soybean early vegetative growth and that this growth inhibition induced by Pcz could be compromised by exogenous BL applications

Summary

Introduction

Soybean is a widely grown grain legume and one of the most important economic crop species. Brassinosteroids play a crucial role in plant vegetative growth and reproductive development It remains unclear how BRs regulate the developmental processes in soybean, and the molecular mechanism underlying soybean early development is largely unexplored. The growth defects of the BR-insensitive mutant bri[1,2,3,4,5] can be complemented by overexpressing GmBRI122,23 These extensive physiological and genetic findings indicate that BRs play important roles during soybean development and that the identified major signaling components in soybean coordinate soybean development. The discovery and use of BR-specific biosynthesis inhibitors have provided an alternative way to determine the physiological functions of BRs in crop species[24,25,26] Among these inhibitors, propiconazole (Pcz) has been reported to be a specific and affordable BR biosynthesis inhibitor for Arabidopsis and maize. Large-scale RNA-seq transcriptome analyses have revealed BR-regulated gene expression networks in Arabidopsis, Gerbera hybrid, etc.[27,28,29]

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