GmPGL2, Encoding a Pentatricopeptide Repeat Protein, Is Essential for Chloroplast RNA Editing and Biogenesis in Soybean

Xingxing Feng; Suxin Yang; Yaohua Zhang; Cheng Zhiyuan; Kuanqiang Tang; Guang Li; Hui Yu; Jiantian Leng; Qingyu Wang

doi:10.3389/fpls.2021.690973

GmPGL2, Encoding a Pentatricopeptide Repeat Protein, Is Essential for Chloroplast RNA Editing and Biogenesis in Soybean

Front Plant Sci. 2021 Sep 9:12:690973. doi: 10.3389/fpls.2021.690973. eCollection 2021.

Authors

Xingxing Feng^{1

2}, Suxin Yang², Yaohua Zhang², Cheng Zhiyuan², Kuanqiang Tang², Guang Li², Hui Yu², Jiantian Leng², Qingyu Wang³

Affiliations

¹ College of Food and Biological Engineering, Xuzhou University of Technology, Xuzhou, China.
² Key Laboratory of Soybean Molecular Design Breeding, Northeast Institute of Geography and Agroecology, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Changchun, China.
³ College of Plant Science, Jilin University, Changchun, China.

Abstract

Chloroplast biogenesis and development are highly complex processes requiring interactions between plastids and nuclear genomic products. Pentatricopeptide repeat (PPR) proteins play an essential role in the development of chloroplasts; however, it remains unclear how RNA editing factors influence soybean development. In this study, a Glycine max pale green leaf 2 mutant (Gmpgl2) was identified with decreased chlorophyll contents. Genetic mapping revealed that a single-nucleotide deletion at position 1949 bp in the Glyma.05g132700 gene in the Gmpgl2 mutant, resulting in a truncated GmPGL2 protein. The nuclear-encoded GmPGL2 is a PLS-type PPR protein that localizes to the chloroplasts. The C-to-U editing efficiencies of rps16, rps18, ndhB, ndhD, ndhE, and ndhF were reduced in the Gmpgl2 mutant. RNA electrophoresis mobility shift assay (REMSA) analysis further revealed that GmPGL2 binds to the immediate upstream sequences at RNA editing sites of rps16 and ndhB in vitro, respectively. In addition, GmPGL2 was found to interact with GmMORF8, GmMORF9, and GmORRM6. These results suggest that GmPGL2 participates in C-to-U RNA editing via the formation of a complex RNA editosome in soybean chloroplasts.

Keywords: RNA editing; chloroplast function; genetic mapping; pentatricopeptide repeat protein; soybean.