SummaryOver‐application of potassium (K) fertilizer in fields has a negative impact on the environment. Developing rice varieties with high KUE will reduce fertilizer for sustainable agriculture. However, the genetic basis of KUE in a more diverse and inclusive population remains largely unexplored. Here, we show that the transcription factor OsNAC25 enhances K+ uptake and confers high KUE under low K+ supply. Disruption of OsNAC25 by CRISPR/Cas9‐mediated mutagenesis led to a considerable loss of K+ uptake capacity in rice roots, coupled with reduced K+ accumulation in rice and severe plant growth defects under low‐ K+ conditions. However, the overexpression of OsNAC25 enhanced K+ accumulation by regulating proper K+ uptake capacity in rice roots. Further analysis displayed that OsNAC25 can bind to the promoter of OsSLAH3 to repress its transcription in response to low‐ K+ stress. Nucleotide diversity analyses suggested that OsNAC25 may be selected during japonica populations' adaptation of low K+ tolerance. Natural variation of OsNAC25 might cause differential expression in different haplotype varieties, thus conferring low K+ tolerance in the Hap 1 and Hap 4 ‐carrying varieties, and the japonica allele OsNAC25 could enhance low K+ tolerance in indica variety, conferring great potential to improve indica low K+ tolerance and grain development. Taken together, we have identified a new NAC regulator involved in rice low K+ tolerance and grain development, and provide a potential target gene for improving low K+ tolerance and grain development in rice.

中文翻译：

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转录因子 OsNAC25 调节水稻钾稳态


摘要在田间过度施用钾 （K） 肥料会对环境产生负面影响。开发具有高 KUE 的水稻品种将减少肥料，实现可持续农业。然而，在更加多样化和包容性的人群中，KUE 的遗传基础在很大程度上仍未得到探索。在这里，我们表明转录因子 OsNAC25 增强 K+ 摄取并在低 K+ 供应下赋予高 KUE。CRISPR/Cas9 介导的诱变破坏 OsNAC25 导致水稻根系 K+ 摄取能力的显著损失，再加上水稻中 K+ 积累减少，在低 K+ 条件下出现严重的植物生长缺陷。然而，OsNAC25 的过表达通过调节水稻根系适当的 K+ 摄取能力来增强 K+ 积累。进一步分析表明，OsNAC25 可以与 OsSLAH3 的启动子结合，以抑制其响应低 K+ 应激的转录。核苷酸多样性分析表明，OsNAC25 可能在粳稻种群适应低 K+ 耐受性过程中被选择。OsNAC25 的自然变异可能导致不同单倍型品种的差异表达，从而赋予携带 Hap 1 和 Hap 4 的品种低 K+ 耐受性，而粳稻等位基因 OsNAC25 可以增强籼稻低 K+ 耐受性，为改善籼稻低 K+ 耐受性和籽粒发育赋予巨大潜力。综上所述，我们确定了一种参与水稻低 K+ 耐受性和籽粒发育的新 NAC 调节因子，并为改善水稻低 K+ 耐受性和籽粒发育提供了潜在的靶基因。