Wang Ke, Xu Feiyun, Yuan Wei, Zhang Dongping, Liu Jianping, Sun Leyun, Cui Liyou, Zhang Jianhua, Xu Weifeng
Joint International Research Laboratory of Water and Nutrient in Crops and College of Life Sciences, Center for Plant Water-Use and Nutrition Regulation and College of Resource and Environment, Fujian Agriculture and Forestry University, Fuzhou, 350002, China.
Jiangsu Key Laboratory of Crop Genetics and Physiology, Co-Innovation Center for Modern Production Technology of Grain Crops, Key Laboratory of Plant Functional Genomics of the Ministry of Education, Yangzhou University, Yangzhou, 225009, China.
Plant J. 2021 Sep;107(6):1603-1615. doi: 10.1111/tpj.15402. Epub 2021 Jul 28.
Heterotrimeric G protein is involved in plant growth and development, while the role of rice (Oryza sativa) G protein γ subunit qPE9-1 in response to low-phosphorus (LP) conditions remains unclear. The gene expression of qPE9-1 was significantly induced in rice roots under LP conditions. Rice varieties carrying the qPE9-1 allele showed a stronger primary root response to LP than the varieties carrying the qpe9-1 allele (mutant of the qPE9-1 allele). Transgenic rice plants with the qPE9-1 allele had longer primary roots and higher P concentrations than those with the qpe9-1 allele under LP conditions. The plasma membrane (PM) H -ATPase was important for the qPE9-1-mediated response to LP. Furthermore, OsGF14b, a 14-3-3 protein that acts as a key component in activating PM H -ATPase for root elongation, is also involved in the qPE9-1 mediation. Moreover, the overexpression of OsGF14b in WYJ8 (carrying the qpe9-1 allele) partially increased primary root length under LP conditions. Experiments using R18 peptide (a 14-3-3 protein inhibitor) showed that qPE9-1 is important for primary root elongation and H efflux under LP conditions by involving the 14-3-3 protein. In addition, rhizosheath weight, total P content, and the rhizosheath soil Olsen-P concentration of qPE9-1 lines were higher than those of qpe9-1 lines under soil drying and LP conditions. These results suggest that the G protein γ subunit qPE9-1 in rice plants modulates root elongation for phosphorus uptake by involving the 14-3-3 protein OsGF14b and PM H -ATPase, which is required for rice P use.
异源三聚体G蛋白参与植物的生长发育，而水稻G蛋白γ亚基qPE9-1在低磷（LP）条件下的作用仍不清楚。在LP条件下，水稻根中qPE9-1的基因表达显著上调。携带qPE9-1等位基因的水稻品种对LP的初生根响应比携带qpe9-1等位基因（qPE9-1等位基因的突变体）的品种更强。在LP条件下，携带qPE9-1等位基因的转基因水稻植株比携带qpe9-1等位基因的植株具有更长的初生根和更高的磷浓度。质膜（PM）H⁺-ATP酶对qPE9-1介导的LP响应很重要。此外，OsGF14b是一种14-3-3蛋白，是激活PM H⁺-ATP酶促进根伸长的关键成分，也参与qPE9-1介导的过程。此外，在WYJ8（携带qpe9-1等位基因）中过表达OsGF14b在LP条件下部分增加了初生根长度。使用R18肽（一种14-3-3蛋白抑制剂）的实验表明，qPE9-1通过涉及14-3-3蛋白对LP条件下的初生根伸长和H⁺外流很重要。此外，在土壤干燥和LP条件下，qPE9-1品系的根际土壤重量、总磷含量和根际土壤有效磷浓度均高于qpe9-1品系。这些结果表明，水稻植株中的G蛋白γ亚基qPE9-1通过涉及14-3-3蛋白OsGF14b和PM H⁺-ATP酶来调节根伸长以吸收磷，这是水稻磷利用所必需的。
