PDF(Pubmed)
Abstract：
Freezing stress can seriously affect plant growth and development, but the mechanisms of these effects and plant responses to freezing stress require further exploration. Here, we identified a NAM, ATAF1/2, and CUC2 (NAC)-family transcription factor (TF), NAC056, that can promote freezing tolerance in Arabidopsis. NAC056 mRNA levels are strongly induced by freezing stress in roots, and the nac056 mutant exhibits compromised freezing tolerance. NAC056 acts positively in response to freezing by directly promoting key C-repeat-binding factor (CBF) pathway genes. Interestingly, we found that CBF1 regulates nitrate assimilation by regulating the nitrate reductase gene NIA1 in plants; therefore, NAC056-CBF1-NIA1 form a regulatory module for the assimilation of nitrate and the growth of roots under freezing stress. In addition, 35S::NAC056 transgenic plants show enhanced freezing tolerance, which is partially reversed in the cbfs triple mutant. Thus, NAC056 confers freezing tolerance through the CBF pathway, mediating plant responses to balance growth and freezing stress tolerance.
摘要：
众所周知，冰冻胁迫会严重影响植物的生长发育。然而,这些效应的机制和植物对冰冻胁迫的反应需要进一步探索。这里,我们确定了一个NAC家族转录因子（TF）NAC056，可以促进冷冻耐受性。冷冻胁迫对根系NAC056mRNA水平有明显的诱导作用。我们表明nac056突变体损害了冷冻耐受性。NAC056通过直接促进关键CBF途径基因而在响应冷冻方面起积极作用。有趣的是,我们发现CBF1通过调节硝酸还原酶基因调节硝酸盐同化，NIA1，在植物中，因此,NAC056-CBF1-NIA1是冻结胁迫下硝酸盐同化和根系生长的调节模块。此外,35S::NAC056转基因植物促进耐冻性。cbfs三重突变体可以部分逆转35S::NAC056诱导的冷冻耐受性。因此，NAC056通过CBF途径赋予冷冻耐受性。因此,NAC056介导植物平衡植物生长和冻结胁迫耐受性的反应。
