Xiong Jing, Zhang Weixiao, Zheng Dan, Xiong Hao, Feng Xuanjun, Zhang Xuemei, Wang Qingjun, Wu Fengkai, Xu Jie, Lu Yanli
Maize Research Institute, Sichuan Agricultural University, Wenjiang 611130, China.
State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Wenjiang 611130, China.
Plants (Basel). 2022 May 23;11(10):1382. doi: 10.3390/plants11101382.
Drought stress is known to significantly limit crop growth and productivity. Lateral organ boundary domain (LBD) transcription factors-particularly class-I members-play essential roles in plant development and biotic stress. However, little information is available on class-II genes related to abiotic stress in maize. Here, we cloned a maize class-II LBD transcription factor, and identified its function in drought stress. Transient expression, transactivation, and dimerization assays demonstrated that was localized in the nucleus, without transactivation, and could form a homodimer or heterodimer. Promoter analysis demonstrated that multiple drought-stress-related and ABA response cis-acting elements are present in the promoter region of . Overexpression of in Arabidopsis promotes plant growth under normal conditions, and suppresses drought tolerance under drought conditions. Furthermore, the overexpression of increased the water loss rate, stomatal number, and stomatal apertures. DAB and NBT staining demonstrated that the reactive oxygen species (ROS) decreased in -overexpressed Arabidopsis. A physiological index assay also revealed that SOD and POD activities in -overexpressed Arabidopsis were higher than those in wild-type Arabidopsis. These results revealed the role of in drought stress by regulating ROS levels.
干旱胁迫已知会显著限制作物生长和生产力。侧生器官边界结构域（LBD）转录因子——特别是I类成员——在植物发育和生物胁迫中发挥重要作用。然而，关于玉米中与非生物胁迫相关的II类基因的信息却很少。在此，我们克隆了一个玉米II类LBD转录因子，并鉴定了其在干旱胁迫中的功能。瞬时表达、反式激活和二聚化分析表明，该转录因子定位于细胞核，无反式激活作用，且能形成同二聚体或异二聚体。启动子分析表明，在该转录因子的启动子区域存在多个与干旱胁迫相关和脱落酸应答的顺式作用元件。在拟南芥中过表达该转录因子在正常条件下促进植物生长，而在干旱条件下抑制耐旱性。此外，过表达该转录因子会增加水分流失率、气孔数量和气孔孔径。二氨基联苯胺（DAB）和氮蓝四唑（NBT）染色表明，在过表达该转录因子的拟南芥中活性氧（ROS）减少。生理指标分析还显示，过表达该转录因子的拟南芥中的超氧化物歧化酶（SOD）和过氧化物酶（POD）活性高于野生型拟南芥。这些结果揭示了该转录因子通过调节ROS水平在干旱胁迫中的作用。
