Plant Physiology and Biochemistry ( IF 6.5 ) Pub Date : 2020-06-10 , DOI: 10.1016/j.plaphy.2020.06.014 Min Wu 1 , Rui Liu 1 , Yameng Gao 2 , Rui Xiong 1 , Yanan Shi 1 , Yan Xiang 3
Abscisic acid, stress and ripening (ASR) transcription factors comprise a small family of proteins that play a key role in stress responses in plants. ASR genes involved in drought tolerance in moso bamboo (Phyllostachys edulis) are largely unknown. In our study, an ASR gene, PheASR2, was isolated and characterized. The expression of PheASR2 was up-regulated under various abiotic stresses, including drought, salt and abscisic acid (ABA). PheASR2 was localized in the nucleus in tobacco cells, and displayed transactivation activity in yeast. Ectopic expression of PheASR2 in rice conferred enhanced tolerance to drought stress, as determined through physiological analyses of germination rate, plant height, water loss and survival rate. The PheASR2-overexpressing transgenic plants showed an increase in reactive oxygen species (ROS), electrolyte leakage and malondialdehyde levels, reduced enzyme (CAT and SOD) activities, and higher expression of genes encoding ROS-scavenging enzymes. Consequently, the transgenic plants exhibited increased tolerance to oxidative stress compared with wild-type plants. Moreover, following ABA treatment, the seed germination rate and plant height of the PheASR2-overexpressing lines were inhibited, and stomatal closure was reduced. The expression of marker genes, including, OsAREB, OsP5CS1, OsLEA, and OsNCED2, was up-regulated in the PheASR2-overexpressing lines when subjected to drought treatment. Together, these results indicate that PheASR2 functions in drought stress tolerance through ABA signaling.
中文翻译:
PheASR2是一种来自毛竹(Phyllostachys edulis)的新型胁迫响应转录因子,可通过提高对脱落酸的敏感性来增强转基因水稻的耐旱性。
脱落酸,胁迫和成熟(ASR)转录因子包括一小类蛋白质,在植物的胁迫反应中起关键作用。毛竹(Phyllostachys edulis)的耐旱性ASR基因在很大程度上是未知的。在我们的研究中,分离并鉴定了ASR基因PheASR2。在各种非生物胁迫下,包括干旱,盐和脱落酸(ABA),PheASR2的表达上调。PheASR2位于烟草细胞的细胞核中,并在酵母中显示出反式激活活性。PheASR2的异位表达通过对发芽率,株高,水分流失和成活率的生理分析确定,水稻中的抗旱性提高了对干旱胁迫的耐受性。所述PheASR2 -overexpressing转基因植物表现出的活性氧物种的增加(ROS),电解质泄漏和丙二醛的水平,减少的酶(CAT和SOD)活性,以及编码ROS清除酶的基因的较高表达。因此,与野生型植物相比,转基因植物对氧化应激表现出增加的耐受性。此外,在ABA处理之后,PheASR2过表达品系的种子发芽率和植物高度受到抑制,并且气孔关闭减少。标记基因的表达,包括OsAREB,进行干旱处理时,PheASR2过表达株系中的OsP5CS1,OsLEA和OsNCED2被上调。总之,这些结果表明PheASR2通过ABA信号传导在干旱胁迫耐受性中起作用。