A study published in the Plant Biotechnology Journal provides new insights for optimizing sorghum canopy architecture. The research found that regulating sorghum leaf angles through bioengineering can significantly enhance photosynthetic efficiency, biomass accumulation, and grain yield without increasing water consumption.

Plant architecture profoundly influences the micro-environment of crop canopies. For gramineous plants, the ligule and auricle formed at the junction of the leaf sheath and blade are key anatomical features regulating leaf angle. The study discovered that mutations in the liguleless genes SbLG1 and SbLG2 lead to the absence of ligules and auricles, causing excessive vertical leaf growth and impairing light interception efficiency. To balance leaf erectness with light capture ability, the research team adopted a gene downregulation strategy by constructing hairpin structure binary vectors and introducing regulatory elements into the sorghum genotype RTx430, successfully breeding sorghum lines with moderately reduced leaf angles.

Greenhouse molecular and phenotypic identification showed that transgenic sorghum, although lacking ligules, had significantly lower leaf verticality compared to null mutants, avoiding the negative impact of excessive erectness on light interception. Field trials further confirmed that plots planted with this line exhibited enhanced photosynthesis in the lower canopy, significantly increased aboveground biomass and seed yield, without additional water use.

This study is the first to validate the economic value of regulating sorghum leaf angles through bioengineering, providing proof-of-concept for creating a "smart canopy." The so-called "smart canopy" achieves efficient utilization of light energy within the canopy by optimizing leaf spatial distribution. The research team pointed out that moderate optimization of leaf angles is an effective means to sustainably increase yields in bioeconomy crops, marking a key step in the "design-build-test-learn" cycle system in crop canopy engineering.

In the future, this technology is expected to be applied to other gramineous crops, providing innovative solutions for global food security and sustainable agricultural development through precise regulation of leaf structure.