Simultaneous Improvement of Grain Yield and Quality through Manipulating Two Type C G Protein Gamma Subunits in Rice.

Lian Wu,Zhiwen Yu,Quan Xu,Xin Cui,Xiaodong Wang

doi:10.3390/ijms23031463

Abstract

Heterotrimeric G protein signaling is an evolutionarily conserved mechanism in diverse organisms that mediates intracellular responses to external stimuli. In rice, the G proteins are involved in the regulation of multiple important agronomic traits. In this paper, we present our finding that two type C G protein gamma subunits, DEP1 and GS3, antagonistically regulated grain yield and grain quality. The DEP1 gene editing we conducted, significantly increased the grain number per panicle but had a negative impact on taste value, texture properties, and chalkiness-related traits. The GS3 gene editing decreased grain number per panicle but significantly increased grain length. In addition, the GS3 gene-edited plants showed improved taste value, appearance, texture properties, and Rapid Visco Analyser (RVA) profiles. To combine the advantages of both gs3 and dep1, we conducted a molecular design breeding at the GS3 locus of a “super rice” variety, SN265, which has a truncated dep1 allele with erect panicle architecture, high-yield performance, and which is of mediocre eating quality. The elongated grain size of the sn265/gs3 gene-edited plants further increased the grain yield. More importantly, the texture properties and RVA profiles were significantly improved, and the taste quality was enhanced. Beyond showcasing the combined function of dep1 and gs3, this paper presents a strategy for the simultaneous improvement of rice grain yield and quality through manipulating two type C G protein gamma subunits in rice.

Highlights

The challenge of meeting the increasing worldwide demand for rice production has driven a sustained quest for advances in rice breeding
To conduct a comprehensive investigation of the phenotypic changes in the DEP1 and GS3 lines, we generated the mutants of two G protein gamma subunits using CRISPR/Cas9 gene-editing technology under the genetic background of the japonica rice variety Sasanishiki (WT)
DEP1 and GS3 represent type C G protein gamma subunits that are widespread throughout seed plants but do not exist in animals [6,11]

Summary

Introduction

The challenge of meeting the increasing worldwide demand for rice production has driven a sustained quest for advances in rice breeding. The last century has witnessed the introduction of semi-dwarf and hybrid rice varieties, leading to quantum leaps in productivity that increased China’s rice yield from 1.9 t ha−1 in 1949 to 7.0 t ha−1 in 2018 (http://faostat.fao.org/; Data: 12 October 2021). In China’s national new rice variety trial, the average yield of new varieties from 2004 to 2018 reached 9.6 t ha−1 [2]. As the economy and living standards have significantly improved during recent decades, studies have focused on rice quality. Eating and cooking quality (ECQ) is one of the most important determinants of grain quality. It is challenging to simultaneously improve grain yield and quality

Objectives

Methods

Results

Conclusion