a Department of Biotechnology and Kumho Life Science Laboratory, College of Agriculture and Life Sciences , Chonnam National University , Gwangju , South Korea.
b Graduate School of Biotechnology and Crop Biotech Institute , Kyung Hee University , Yongin , South Korea.
Plant Signal Behav. 2019;14(3):e1578633. doi: 10.1080/15592324.2019.1578633. Epub 2019 Feb 14.
Approximately 75 MAP kinase kinase kinases (MAPKKKs) have been identified in the rice genome. However, only a few of them have been functionally characterized. In this paper, we report the function of a rice MAPKKK, OsMAPKKK63. OsMAPKKK63 was found to be induced by several abiotic stresses, including high salinity, chilling and drought. Our data indicate that OsMAPKKK63 possesses in vitro kinase activity and that it interacts with rice MAP kinase kinase OsMKK1 and OsMKK6. The two rice MKKs are known mediator of the salt stress response, implying that OsMAPKKK63 may be involved in the high salinity response. Our analysis of an OsMAPKKK63 knockout mutant indeed demonstrated that it is necessary for normal response to high salt. On the other hand, OsMAPKKK63 OX lines exhibited viviparous phenotype in both rice and Arabidopsis. The result suggests that OsMAPKKK63 may also be involved in seed dormancy control.
在水稻基因组中大约鉴定出 75 种丝裂原活化蛋白激酶激酶激酶（MAPKKKs）。然而，其中只有少数几种具有功能特征。在本文中，我们报告了一种水稻 MAPKKK，OsMAPKKK63 的功能。发现 OsMAPKKK63 受到多种非生物胁迫的诱导，包括高盐、冷胁迫和干旱。我们的数据表明 OsMAPKKK63 具有体外激酶活性，并且它与水稻 MAP 激酶激酶 OsMKK1 和 OsMKK6 相互作用。这两种水稻 MKK 是盐胁迫反应的已知介质，这意味着 OsMAPKKK63 可能参与高盐反应。我们对 OsMAPKKK63 敲除突变体的分析确实表明，它对于正常响应高盐是必要的。另一方面，OsMAPKKK63 OX 系在水稻和拟南芥中均表现出胎生表型。结果表明，OsMAPKKK63 也可能参与种子休眠的控制。
