Heterotrimeric G proteins regulate nitrogen-use efficiency in rice
Hongying Sun,Qian Qian,Kun Wu,Jijing Luo,Shuansuo Wang,Chengwei Zhang,Yanfei Ma,Qian Liu,Xianzhong Huang,Qingbo Yuan,Ruixi Han,Meng Zhao,Guojun Dong, Longbiao Guo,Xudong Zhu,Zhiheng Gou,Wen Wang,Yuejin Wu,Hongxuan Lin, Xiangdong Fu
The State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, National Centre for Plant Gene Research, Beijing, China
Abstract: The drive toward more sustainable agriculture has raised the profile of crop plant nutrient-use efficiency. Here we show that a major rice nitrogen-use efficiency quantitative trait locus (qNGR9) is synonymous with the previously identified gene DEP1 (DENSE AND ERECT PANICLES 1). The different DEP1 alleles confer different nitrogen responses, and genetic diversity analysis suggests that DEP1 has been subjected to artificial selection during Oryza sativa spp. japonica rice domestication. The plants carrying the dominant dep1-1 allele exhibit nitrogen-insensitive vegetative growth coupled with increased nitrogen uptake and assimilation, resulting in improved harvest index and grain yield at moderate levels of nitrogen fertilization. The DEP1 protein interacts in vivo with both the Gα (RGA1) and Gβ (RGB1) subunits, and reduced RGA1 or enhanced RGB1 activity inhibits nitrogen responses. We conclude that the plant G protein complex regulates nitrogen signaling and modulation of heterotrimeric G protein activity provides a strategy for environmentally sustainable increases in rice grain yield.