State Key Laboratory of Agrobiotechnology, College of Biological Sciences, Agricultural University, Beijing 100193, China; China Tobacco Jiangsu Industry CO., Ltd, Jiangsu 210011, China.
Joint International Research Laboratory of Metabolic & Developmental Sciences, Shanghai Jiao Tong University-University of Adelaide Joint Centre for Agriculture and Health, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China.
Plant Sci. 2022 Aug;321:111256. doi: 10.1016/j.plantsci.2022.111256. Epub 2022 May 18.
The aerial surfaces of plants are covered by a layer of cuticular wax that is composed of long-chain hydrocarbon compounds for protection against adverse environmental conditions. The current study identified a maize (Zea mays L.) APETALA2/ethylene-responsive element-binding protein (AP2/EREBP)-type transcription factor, ZmEREB46. Ectopic expression of ZmEREB46 in Arabidopsis increased the accumulation of epicuticular wax on the leaves and enhanced the drought tolerance of plants. The amounts of C24/C32 fatty acids, C32/C34 aldehydes, C32/C34 1-alcohols and C31 alkanes in zmereb46 (ZmEREB46 knockout mutant) leaves were reduced. The amount of leaf total epicuticular wax decreased approximately 50% in zmereb46. Compared to wild-type LH244 leaves, the cuticle permeability of zmereb46 leaves was increased, which resulted from decreased epicuticular wax load and a thinner cuticle layer. ZmEREB46 had transcriptional activation activity and directly bound to promoter regions of ZmCER2, ZmCER3.2 and ZmKCS1. The zmereb46 seedlings also exhibited reduced drought tolerance. These results, and the observations in ZmEREB46-overexpressing lines, suggest that ZmEREB46 is involved in cuticular metabolism by influencing the biosynthesis of very-long-chain waxes and participates in the cutin biosynthesis pathway. These results are helpful to further analyze the regulatory network of wax accumulation in maize.
植物的气生表面被一层由长链碳氢化合物组成的角质层蜡所覆盖，以防止其受到不利环境条件的影响。本研究鉴定了一种玉米（Zea mays L.）APETALA2/乙烯响应元件结合蛋白（AP2/EREBP）- 型转录因子，ZmEREB46。在拟南芥中异位表达 ZmEREB46 会增加叶片上的角质层蜡的积累，并增强植物的耐旱性。ZmEREB46（ZmEREB46 敲除突变体）叶片中 C24/C32 脂肪酸、C32/C34 醛、C32/C34 1-醇和 C31 烷烃的含量减少。ZmEREB46 叶片中的总角质层蜡含量减少了约 50%。与野生型 LH244 叶片相比，Zmereb46 叶片的角质层通透性增加，这是由于角质层蜡负荷减少和角质层层变薄所致。ZmEREB46 具有转录激活活性，并直接与 ZmCER2、ZmCER3.2 和 ZmKCS1 的启动子区域结合。Zmereb46 幼苗的耐旱性也降低。这些结果以及在 ZmEREB46 过表达系中的观察结果表明，ZmEREB46 通过影响超长链蜡的生物合成参与角质层代谢，并参与角质生物合成途径。这些结果有助于进一步分析玉米中蜡积累的调控网络。
