Molecular mechanism of tillering response to nitrogen in rice.

Nitrogen (N) fertilizer acts as the main driving force for agricultural productivity improvement. However, overuse of N fertilizer has caused severe effects to environment and ecosystem. Thus, it is pivotal to improve nitrogen use efficiency (NUE) for future sustainable agriculture. Agronomic traits response to N are significant indices for NUE phenotyping. For example, tiller number, grain number per panicle, and grain weight are three major components for cereal yields. Although regulatory mechanisms regarding to these three traits have been largely reported, few is known about how N affects them. Tiller number is one of the most sensitive traits response to N and also plays a key role for N-promoted yield improvement. It is thereby of great significance to dissect the genetic basis underlying tillering response to N. In this review, we summarize the factors contributing to NUE as well as the regulatory mechanisms over rice tillering and emphasize how N affects rice tillering, future research directions are also discussed for further improving NUE.氮肥是作物产量增加最主要的驱动因素，然而氮肥滥用会造成生态环境的严重破坏。因此，提高作物氮素利用效率(nitrogen use efficiency，NUE)对未来农业可持续发展至关重要。产量性状对氮素的敏感性是衡量作物氮素利用效率的重要指标。禾本科作物的分蘖数、穗粒数和粒重是产量的直接决定因子，虽然影响三者本身的分子机制已有大量研究，但氮素对这些性状的调控机理仍知之甚少。分蘖数是对氮素响应最为敏感的性状之一，也是氮肥促进作物增产的关键要素。因此，研究氮素如何调控水稻的分蘖发育对于提高作物产量尤为重要。本文总结了水稻氮素利用效率的影响因素和分蘖发育的调控机理，聚焦氮素如何调控水稻分蘖发育的机制，并对该领域未来研究工作进行了展望，以期为作物氮高效精准改良提供参考。.