Leaf width gene LW5/D1 affects plant architecture and yield in rice by regulating nitrogen utilization efficiency

Area of Science:

• Plant Science
• Genetics
• Agricultural Science

Background:

• Leaf morphology is crucial for rice plant architecture and yield, influenced by both architecture and nutrient utilization.
• The molecular links between plant architecture, nutrient use, and rice yield remain largely unexplored.

Purpose of the Study:

• To investigate the function of the LW5 gene in rice.
• To understand the molecular mechanisms connecting plant architecture, nutrient transfer, and yield in rice.

Main Methods:

• Map-based cloning and CRISPR-Cas9 gene editing were used to identify and analyze the LW5 gene.
• Physiological and molecular analyses, including 15N-ammonium nitrate tracing and gene expression analysis, were performed.

Main Results:

• The lw5 mutant exhibits wide leaves, small grains, increased photosynthesis, and higher chlorophyll content, characteristic of a "source-sink" imbalance.
• Loss of LW5 function significantly reduced the grain-straw ratio and grain filling rate.
• LW5 plays a critical role in nitrate uptake and transport, influencing nitrogen transfer.

Conclusions:

• LW5 is an allele of D1, encoding the rice G protein α subunit, and is vital for regulating nitrogen transfer.
• LW5 impacts rice plant architecture and grain size by modulating nitrogen transport, providing insights into source-sink dynamics.
• Findings offer a basis for breeding super rice varieties with ideal plant types and improved molecular design.