Leaf width gene LW5/D1 affects plant architecture and yield in rice by
Yuchen Zhu +, Ting Li +, Jing Xu +, Jiajia Wang , Li Wang , Weiwei Zou , Dali Zeng ，Li Zhu , Guang Chen , Jiang Hu , Zhenyu Gao , Guojun Dong , Deyong Ren , Lan Shen ,Qiang Zhang , Longbiao Guo , Songping Hu ***, Qian Qian **, Guangheng Zhang *
Plant Physiology and Biochemistry
10.1016/j.plaphy.2020.10.035
Abstract
Leaves are the primary structures responsible for photosynthesis, making leaf morphology one of the most
important traits of rice plant architecture. Both plant architecture and nutrient utilization jointly affect rice yield,
however, their molecular association is still poorly understood. We identified a rice mutant, leaf width 5 (lw5),
that displayed small grains and wide leaves and possesses characteristics typical of a small “sink” and a large
“source”. Map-based cloning and CRISPR-Cas9 gene editing indicated that LW5 affects both the plant architecture
and yield. It is an allele of D1, encoding the rice G protein α subunit. The loss of LW5 functioning leads to
an increase in the rate of photosynthesis, vascular bundles, and chlorophyll content. However, the grain-straw
ratio and the rate of grain filling decreased significantly. The detection results of 15N-ammonium nitrate and
an expression analysis of genes associated with nitrogen demonstrated that LW5 serves an important role in
nitrate uptake and transport. LW5 affects plant architecture and grain size by regulating nitrogen transfer. These
results provide a theoretical foundation for further research surrounding the molecular mechanism of “sourcesink”
balance in rice and suggest novel methods of molecular design for the cultivation of breeding super rice in
ideal plant types.