College of Tobacco Science, Henan Agricultural University, Zhengzhou 450002, China.
Library of Henan Agricultural University, Zhengzhou 450002, China.
Plant Sci. 2019 Oct;287:110186. doi: 10.1016/j.plantsci.2019.110186. Epub 2019 Jul 9.
Drought is one of the major environmental stresses limiting crop growth and production. It is very important to exploit and utilize drought-tolerance genes to improve crop drought-resistance. In this study, we identified two homoeologs of a Nicotiana tabacum (Ntab) DELAY OF GERMINATION (DOG) 1 like gene, named as NtabDOG1L-T and NtabDOG1L-S, respectively. The NtabDOG1L genes were preferentially expressed in roots and their expression levels were induced by polyethylene glycol, high salt, cold, and abscisic acid treatments. Subcellular localization results indicated that NtabDOG1L-T was localized in the nucleus, cytoplasm and cell membrane. Overexpression of NtabDOG1L-T in tobacco resulted in roots growth enhancement in transgenic plants. Furthermore, overexpression of NtabDOG1L-T enhanced drought stress tolerance in transgenic tobacco. The transgenic tobacco lines exhibited lower leaf water loss and electrolyte leakage, lower content of malondialdehyde and reactive oxygen species (ROS), and higher antioxidant enzymes activities after drought treatment when compared with wild type (WT) plants. In addition, the expression levels of several genes encoding key antioxidant enzymes and drought-related proteins were higher in the transgenic plants than in the WT plants under drought stress. Taken together, our results showed that NtabDOG1L functions as a novel regulator that improves plant growth and drought tolerance in tobacco.
干旱是限制作物生长和生产的主要环境胁迫之一。开发和利用耐旱基因以提高作物抗旱性非常重要。在本研究中，我们鉴定了两个拟南芥（Ntab）延迟萌发（DOG）1 类似基因的同源基因，分别命名为 NtabDOG1L-T 和 NtabDOG1L-S。NtabDOG1L 基因在根中优先表达，其表达水平受聚乙二醇、高盐、低温和脱落酸处理诱导。亚细胞定位结果表明，NtabDOG1L-T 定位于细胞核、细胞质和细胞膜中。在烟草中过表达 NtabDOG1L-T 导致转基因植株根系生长增强。此外，过表达 NtabDOG1L-T 增强了转基因烟草对干旱胁迫的耐受性。与野生型（WT）植物相比，干旱处理后，转基因烟草叶片水分损失和电解质渗漏较少，丙二醛和活性氧（ROS）含量较低，抗氧化酶活性较高。此外，在干旱胁迫下，转基因植物中编码关键抗氧化酶和干旱相关蛋白的几个基因的表达水平高于 WT 植物。总之，我们的研究结果表明，NtabDOG1L 作为一种新的调节剂，可提高烟草的生长和抗旱性。
