1. ZmNRT1.1B (ZmNPF6.6) determines nitrogen use efficiency via regulation of nitrate transport and signalling in maize.
- Author
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Cao, Huairong, Liu, Zhi, Guo, Jia, Jia, Zhongtao, Shi, Yandong, Kang, Kai, Peng, Wushuang, Wang, Zhangkui, Chen, Limei, Neuhaeuser, Benjamin, Wang, Yong, Liu, Xiangguo, Hao, Dongyun, and Yuan, Lixing
- Subjects
CARBON metabolism ,GERMPLASM ,NITRATES ,GRAIN yields ,PLANT growth ,CORN - Abstract
Summary: Nitrate (NO3−) is crucial for optimal plant growth and development and often limits crop productivity under low availability. In comparison with model plant Arabidopsis, the molecular mechanisms underlying NO3− acquisition and utilization remain largely unclear in maize. In particular, only a few genes have been exploited to improve nitrogen use efficiency (NUE). Here, we demonstrated that NO3−‐inducible ZmNRT1.1B (ZmNPF6.6) positively regulated NO3−‐dependent growth and NUE in maize. We showed that the tandem duplicated proteoform ZmNRT1.1C is irrelevant to maize seedling growth under NO3− supply; however, the loss of function of ZmNRT1.1B significantly weakened plant growth under adequate NO3− supply under both hydroponic and field conditions. The 15N‐labelled NO3− absorption assay indicated that ZmNRT1.1B mediated the high‐affinity NO3−‐transport and root‐to‐shoot NO3− translocation. Transcriptome analysis further showed, upon NO3− supply, ZmNRT1.1B promotes cytoplasmic‐to‐nuclear shuttling of ZmNLP3.1 (ZmNLP8), which co‐regulates the expression of genes involved in NO3− response, cytokinin biosynthesis and carbon metabolism. Remarkably, overexpression of ZmNRT1.1B in modern maize hybrids improved grain yield under N‐limiting fields. Taken together, our study revealed a crucial role of ZmNRT1.1B in high‐affinity NO3− transport and signalling and offers valuable genetic resource for breeding N use efficient high‐yield cultivars. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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