Serendipita indica promotes rice phosphorus uptake by plasma membrane H+-ATPase OsA1-stimulated root hair growth
Feiyun Xu, Fan Ding, Renhao Zheng, Lu Tong, Chuqi Bai, Zhen Chen, Jin Li, Peilin Li, Jiaming Zhang, Qian Zhang, Jianping Liu, Yiyong Zhu, Jianhua Zhang, Jiayin Pang, Weifeng XuAbstract
Plasma membrane (PM) H+-ATPase is important for plant phosphorus (P) uptake. The endophytic fungus Serendipita indica (S. indica) can increase plant P acquisition under P deficiency conditions, but it is unclear whether PM H+-ATPase OsA1 is involved in S. indica-modulated P uptake in rice. Under low-P conditions, rice seedlings inoculated with S. indica showed a 90% increase in shoot P concentration and a 164% increase in root P concentration compared with the non-inoculated rice, largely due to significantly elongated root hairs. The relative expression of OsA1 in S. indica-inoculated plants was 73.2% higher than in non-inoculated S. indica plants under low-P conditions. Under low-P conditions, S. indica inoculation also enhanced root H+ efflux by 34% and PM H+-ATPase activity by 27% in wild-type rice compared with non-inoculated plants, whereas no such significant difference was observed in the osa1-1 or osa1-2 mutants. Taken together, our results suggest that S. indica promotes root hair growth under low-P conditions by modulating plasma membrane H+-ATPase OsA1. This cooperative interaction reveals a key mechanism through which S. indica enhances P acquisition, providing valuable insights for improving P-use efficiency in rice production.