Date Published: September 29, 2017
Publisher: Springer Berlin Heidelberg
Author(s): Yong Zhou, Peng He, Yaping Xu, Qiang Liu, Yingui Yang, Shiqiang Liu.
As the group II LEA (late embryogenesis abundant) proteins, dehydrins (DHNs) play an important role in plant growth and development, as well as in response to abiotic or biotic stress challenges. In this study, a DHN gene named CsLEA11 was identified and characterized from Cucumis sativus. Sequence analysis of CsLEA11 showed that it is a Y3SK2-type DHN protein rich in hydrophilic amino acids. Expression analyses revealed that the transcription of CsLEA11 could be significantly induced by heat and cold stress. The recombinant plasmid was transformed into Escherichia coli BL21 and isopropy-β-d-thiogalactoside (IPTG) was used to induce recombinant E. coli to express CsLEA11 gene. Overexpression of CsLEA11 in E. coli enhanced cell viability and conferred tolerance to heat and cold stress. Furthermore, CsLEA11 protein could protect the activity of lactate dehydrogenase (LDH) under heat stress. Taken together, our data demonstrate that CsLEA11 might function in tolerance of cucumber to heat and cold stress.
Temperature is one of the major factors affecting plant growth and productive capacity (Guo et al. 2017). Higher plants have evolved a variety of strategies for continuous changes to deal with the unfavorable stresses, such as heat and cold. For example, LEA (late embryogenesis abundant) proteins are synthesized in large amounts during the late stages of seed development, enabling the maturing seeds to acquire desiccation tolerance, which plays an important role in the adaptation of plants to abiotic stresses (Hu et al. 2016; Tang et al. 2016; Tolleter et al. 2007).
Over the past few decades, numerous DHN genes have been identified in various plant species, and were demonstrated to play important roles in abiotic stress tolerance (Banerjee and Roychoudhury 2016; Liu et al. 2017). In this study, a DHN gene named CsLEA11 was for the first time isolated and characterized from C. sativus. Sequence alignment and phylogenetic analysis indicate that CsLEA11 belongs to the Y3SK2 group. Gene expression analyses are important for the revealing of gene functions. There are increasing evidences showing that DHN genes are regulated by various abiotic stresses including heat and cold (Lv et al. 2017; Wahid and Close 2007; Yang et al. 2012). In this study, the transcription of CsLEA11 was induced by heat and cold treatments (Fig. 4), implying a positive correlation between CsLEA11 and tolerance to heat or cold stress.