The opposite roles of OsmiR408 in cold and drought stress responses in Oryza sativa
The opposite roles of OsmiR408 in cold and drought stress responses in Oryza sativa
复制标题
OsmiR408在水稻冷胁迫和干旱胁迫反应中的相反作用
DOI：
10.1007/s11032-018-0877-z
复制
发表时间：
2018-10-01
影响因子：
3.1
通讯作者：
Sun, Xiaoli
中科院分区：
文献类型：
--
作者：
Sun, Mingzhe;Yang, Junkai;Sun, Xiaoli
miR408是植物中一个保守的微小RNA（miRNA）家族。尽管拟南芥miR408通常被认为参与胁迫应答，但水稻miR408（OsmiR408）是否调节对环境胁迫的耐受性仍不清楚。在本研究中，发现水稻品种“空育131”中，OsmiR408前体（Pre - OsmiR408）和OsmiR408的表达受冷胁迫诱导，但受干旱胁迫抑制。通过比较野生型和OsmiR408转基因株系，我们发现OsmiR408过表达在幼苗早期和幼苗期均增强了耐寒性。另一方面，OsmiR408转基因株系表现出耐旱性下降，这通过更大的水分流失进一步得到验证。我们还预测了OsmiR408的潜在靶基因，并验证了OsmiR408转基因株系中7个靶基因表达降低，包括4个植物花青素蛋白基因和3个非典型靶基因。其中，植物花青素蛋白基因Os09g29390和生长素响应的Aux/IAA基因Os01g53880受冷处理下调，这与冷诱导的OsmiR408表达相反。综上所述，我们的结果表明OsmiR408在植物对寒冷和干旱胁迫的响应中具有相反的作用。
MiR408 is a conserved miRNA family in plants. Although AtmiR408 is generally regarded as participating in stress responses, it still remains obscure whether OsmiR408 modulates tolerance to environmental stress. In the current study, expression of Pre-OsmiR408 and OsmiR408 was found to be induced by cold stress, but repressed by drought stress in the rice cultivar “Kongyu 131”. By comparing the wild type and OsmiR408 transgenic lines, we found that OsmiR408 overexpression conferred enhanced cold tolerance at both the early seedling stage and the young seedling stage. On the other hand, the OsmiR408 transgenic lines exhibited decreased drought tolerance, which is further verified by greater water loss. We also predicted the putative target genes of OsmiR408 and verified the decreased expression of seven targets in OsmiR408 transgenic lines, including four phytocyanins and three atypical target genes. Among them, Os09g29390, a phytocyanin gene, and Os01g53880, an auxin responsive Aux/IAA gene, were down-regulated by cold treatment, which is opposite to the cold-induced expression of OsmiR408. Taken together, our results suggest opposite roles of OsmiR408 in plant responses to cold and drought stresses.