posted on 2023-12-12, 19:20authored byDandan Li, Xianxin Wu, Chunyan Huang, Qiujun Lin, Yan Wang, Xu Yang, Chuang Wang, Yuanhu Xuan, Songhong Wei, Qiong Mei
Nitrogen
fertilization can promote rice yield but decrease resistance
to sheath blight (ShB). In this study, the nitrate transporter
1.1b (nrt1.1b) mutant that exhibited less
susceptibility to ShB but without compromising yield under NH4+ fertilization was screened. NRT1.1B’s
regulation of ShB resistance was independent of the total nitrogen
concentration in rice under NH4+ conditions.
In nrt1.1b mutant plants, the NH4+ application modulated auxin signaling, chlorophyll content,
and phosphate signaling to promote ShB resistance. Furthermore, the
findings indicated that NRT1.1B negatively regulated ShB resistance
by positively modulating the expression of H+-ATPase gene OSA3 and phosphate transport gene PT8.
The mutation of OSA3 and PT8 promoted
ShB resistance by increasing the apoplastic pH in rice. Our study
identified the ShB resistance mutant nrt1.1b, which
maintained normal nitrogen use efficiency without compromising yield.