Yue Xiule, Zhang Guoyan, Zhao Zhen, Yue Jinli, Pu Xiaohong, Sui Mengjun, Zhan Yi, Shi Yulan, Wang Zhenyu, Meng Guanghua, Zhao Zhixing, An Lizhe
Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, China.
Cuiying Honors College, Lanzhou University, Lanzhou, China.
Front Plant Sci. 2019 May 31;10:699. doi: 10.3389/fpls.2019.00699. eCollection 2019.
Abscisic acid responsive element binding factors (ABFs) play crucial roles in plant responses to abiotic stress. However, little is known about the roles of ABFs in alpine subnival plants, which can survive under extreme environmental conditions. Here, we cloned and characterized an homolog, , from the alpine subnival plant . Expression of was induced by cold, drought, and abscisic acid. Subcellular localization analysis revealed that CbABF1 was located in the nucleus. Further, CbABF1 had transactivation activity, which was dependent on the N-terminal region containing 89 residues. A Snf1-related protein kinase, CbSnRK2.6, interacted with CbABF1 in yeast two-hybrid analysis and bimolecular fluorescence complementation assays. Transient expression assay revealed that CbSnRK2.6 enhanced the transactivation of CbABF1 on ABRE -element. We further found that heterologous expression of in tobacco improved plant tolerance to freezing and drought stress, in which the survival rates of the transgenic plants increased around 40 and 60%, respectively, compared with wild-type plants. Moreover, the transgenic plants accumulated less reactive oxygen species, accompanied by high activities of antioxidant enzymes and elevated expression of stress-responsive genes. Our results thus suggest that CbABF1 is a transcription factor that plays an important role in cold and drought tolerance and is a candidate gene in molecular breeding of stress-tolerant crops.
脱落酸响应元件结合因子（ABFs）在植物对非生物胁迫的响应中发挥着关键作用。然而，对于能够在极端环境条件下生存的高山亚冰雪带植物中ABFs的作用却知之甚少。在此，我们从高山亚冰雪带植物[植物名称未给出]中克隆并鉴定了一个同源基因[基因名称未给出]。[基因名称未给出]的表达受寒冷、干旱和脱落酸诱导。亚细胞定位分析表明CbABF1定位于细胞核。此外，CbABF1具有反式激活活性，其依赖于包含89个残基的N端区域。在酵母双杂交分析和双分子荧光互补试验中，一种与Snf1相关的蛋白激酶CbSnRK2.6与CbABF1相互作用。瞬时表达试验表明CbSnRK2.6增强了CbABF1对ABRE元件的反式激活。我们进一步发现[基因名称未给出]在烟草中的异源表达提高了植物对冷冻和干旱胁迫的耐受性，与野生型植物相比，转基因植物的存活率分别提高了约40%和60%。此外，转基因植物积累的活性氧较少，同时抗氧化酶活性较高且胁迫响应基因的表达上调。因此，我们的结果表明CbABF1是一种转录因子，在耐寒和耐旱性中起重要作用，是耐逆作物分子育种中的一个候选基因。
