Wang Xiaoyu, Zhang Linsheng, Zhang Yane, Bai Zhenqing, Liu Hao, Zhang Dapeng
College of Life Sciences/State Key Laboratory of Crop Stress Biology for Arid Areas, Northwest A & F University, Yangling, China.
PLoS One. 2017 Feb 16;12(2):e0171340. doi: 10.1371/journal.pone.0171340. eCollection 2017.
WRAB18, an ABA-inducible protein belongs to the third family of late embryogenesis abundant (LEA) proteins which can be induced by different biotic or abiotic stresses. In the present study, WRAB18 was cloned from the Zhengyin 1 cultivar of Triticum aestivum and overexpressed in Escherichia coli to explore its effects on the growth of E. coli under different abiotic stresses. Results suggested the enhanced exhibition of tolerance of E. coli to these stresses. Meanwhile, the WRAB18-transgenic tobacco plants were obtained to analyze the stress-related enzymatic activities of ascorbate peroxidase (APX), peroxidase (POD) and superoxide dismutase (SOD), and to quantify the content of malonaldehyde (MDA) under osmotic stress, high salinity, and low and high temperature stress. The activities of APX, POD and SOD in the transgenic tobacco lines were higher while the content of MDA was lower than those of WT lines. Moreover, plastid localization of WRAB18 in Nicotiana benthamiana plasma cells were found fusing with GFP. In addition, purified WRAB18 protein protected LDH (Lactate dehydrogenase) enzyme activity in vitro from various stress conditions. In brief, WRAB18 protein shows protective action behaving as a "molecular shield" in both prokaryotic and eukaryotic cells under various abiotic stresses, not only during ABA stress.
WRAB18是一种脱落酸诱导蛋白,属于胚胎后期丰富蛋白(LEA)的第三个家族,可被不同的生物或非生物胁迫诱导。在本研究中,从普通小麦品种郑引1号中克隆了WRAB18,并在大肠杆菌中过表达,以探究其在不同非生物胁迫下对大肠杆菌生长的影响。结果表明大肠杆菌对这些胁迫的耐受性增强。同时,获得了WRAB18转基因烟草植株,以分析抗坏血酸过氧化物酶(APX)、过氧化物酶(POD)和超氧化物歧化酶(SOD)等与胁迫相关的酶活性,并量化渗透胁迫、高盐胁迫以及低温和高温胁迫下丙二醛(MDA)的含量。转基因烟草株系中APX、POD和SOD的活性较高,而MDA的含量低于野生型株系。此外,发现WRAB18在本氏烟草叶肉细胞中的质体定位与绿色荧光蛋白融合。另外,纯化的WRAB18蛋白在体外可保护乳酸脱氢酶(LDH)的酶活性免受各种胁迫条件的影响。简而言之,WRAB18蛋白在各种非生物胁迫下,不仅在脱落酸胁迫期间,在原核细胞和真核细胞中都表现出作为“分子护盾”的保护作用。