Improvement of leaf photosynthesis is an important strategy for greater crop productivity. Here we show that the quantitative trait locus GPS(GREEN FORPHOTOSYNTHESIS) in rice (OryzasativaL.) controls photosynthesis rate by regulating carboxylation efficiency. Map-based cloning revealed that GPSis identical to NAL1(NARROW LEAF1), a gene previously reported to control lateral leaf growth. The high-photosynthesis allele of GPSwas found to be a partial loss-of-function allele of NAL1. This allele increased mesophyll cell number between vascular bundles, which led to thickened leaves, and it pleiotropically enhanced photosynthesis rate without the detrimental side effects observed in previously identified nallmutants, such as dwarf plant stature. Furthermore, pedigree analysis suggested that rice breeders have repeatedly selected the high-photosynthesis allele in high-yield breeding programs. The identification and utilization of NAL1(GPS) can enhance future high-yield breeding and provides a new strategy for increasing rice productivity.
ASJC Scopus subject areas