Genetic and Molecular Factors Determining Grain Weight in Rice.

Ke Chen,Mariusz Jaremko,Łukasz Jaremko,Andrzej Łyskowski

doi:10.3389/fpls.2021.605799

Abstract

Grain weight is one of the major factors determining single plant yield production of rice and other cereal crops. Research has begun to reveal the regulatory mechanisms underlying grain weight as well as grain size, highlighting the importance of this research for plant molecular biology. The developmental trait of grain weight is affected by multiple molecular and genetic aspects that lead to dynamic changes in cell division, expansion and differentiation. Additionally, several important biological pathways contribute to grain weight, such as ubiquitination, phytohormones, G-proteins, photosynthesis, epigenetic modifications and microRNAs. Our review integrates early and more recent findings, and provides future perspectives for how a more complete understanding of grain weight can optimize strategies for improving yield production. It is surprising that the acquired wealth of knowledge has not revealed more insights into the underlying molecular mechanisms. To accelerating molecular breeding of rice and other cereals is becoming an emergent and critical task for agronomists. Lastly, we highlighted the importance of leveraging gene editing technologies as well as structural studies for future rice breeding applications.

Highlights

Rice is one of the most important food crops globally
Grain development involves numerous molecular and biological processes related to chromatin modification, transcriptional regulation, translational modification and protein interaction, as well as metabolomic processes related to photosynthesis, accumulation, transportation, distribution and storage, and cellular processes related to cell division, cell differentiation and cell nucleus alteration
They found that greater filled grain numbers per panicle, 1000-grain-weight, plant height, panicle length, grains per panicle, and seed setting rate, longer growth period, lower panicle number per unit area, and lower seed length/width ratio accounted for higher yield in indica inbred and indica hybrid, while only high panicle number per unit area and longer growth period led to higher grain yield in japonica inbred and japonica hybrid varieties

Summary

INTRODUCTION

Rice is one of the most important food crops globally. It is produced and consumed on a large scale, feeding nearly half the world population (Ashikari and Matsuoka, 2006; Kuroha and Ashikari, 2020). It was shown that qGL3/GL3.1 interacts with the GSK3/SHAGGY-Like Kinase OsGSK3 to modulate BR signaling (Gao et al, 2019) Taken together, these results suggest that BR signaling, MAPK signaling and other signaling pathways use phosphorylation for regulating grain size and to coordinate a trade-off of plant developmental priorities. These results suggest nuclear Y factors tightly regulate flower organogenesis Other proteins such as starch branching enzyme (OsBEIIB), isoamylase (ISA1), natural resistance associated macrophage proteins (NRAMP) family 5 (OsNramp5), and ADP-glucose transporter (OsBT1) etc., showed positively associate with the development of rice quality (Yang et al, 2012; Li S. et al, 2017; Sun et al, 2017; Tang et al, 2017; Fiaz et al, 2019; Shufen et al, 2019). Osg1HAT1 overexpression increases histone H4 acetylation, resulting in gene expression changes for phytohormone responses, protein metabolism, the cell cycle and other physiological processes (Song et al, 2015)

DNA binding domain

Findings

CONCLUSION AND PERSPECTIVE