Wen Wuwu, Xie Zheni, Yu Guohui, Zhao Chengliang, Zhang Jing, Huang Linkai, Xu Bin, Huang Bingru
College of Agro-grassland Science, Nanjing Agricultural University, Nanjing, 210095 People's Republic of China.
Department of Grassland Science, Animal Science and Technology College, Sichuan Agricultural University, Ya'an, Sichuan 625014 People's Republic of China.
Hereditas. 2017 Oct 24;155:15. doi: 10.1186/s41065-017-0050-4. eCollection 2018.
The C-repeat-binding factors/DRE-binding factors (CBF/DREBs) comprise a key transcription factor family involved in plant stress tolerance. Yet, there is limited information about switchgrass DREB genes and their functional roles.
In this study, four cold-inducible were identified from switchgrass (), among which was the one responded to cold stress later than the other three . Yet, ectopic overexpression of led to significantly compromised, instead of improved cold tolerance in transgenic tobacco. On the other hand, was transcriptionally down-regulated in response to salt stress, but overexpression of improved plant salt tolerance in transgenic tobacco. The improved salt tolerance was associated with increased K/Na ratio and Ca content, higher cellular osmotic potential, and activation of stress-related functional genes in the leaves of transgenic plants under salt stress.
The current results implied that played opposite roles in plant cold and salt tolerance. Although DREB1s were known as positive stress regulators, particular attentions shall be paid to their potential negative regulatory role(s).
C-重复序列结合因子/脱水应答元件结合因子（CBF/DREB）构成了参与植物胁迫耐受性的关键转录因子家族。然而，关于柳枝稷DREB基因及其功能作用的信息有限。
在本研究中，从柳枝稷（）中鉴定出四个冷诱导基因，其中一个基因对冷胁迫的响应比其他三个基因晚。然而，该基因的异位过表达导致转基因烟草的耐寒性显著受损，而非提高。另一方面，该基因在盐胁迫下转录下调，但在转基因烟草中过表达提高了植物的耐盐性。耐盐性的提高与转基因植物在盐胁迫下叶片中K/Na比值和Ca含量增加、细胞渗透势升高以及胁迫相关功能基因的激活有关。
目前的结果表明该基因在植物耐寒性和耐盐性中发挥相反的作用。尽管DREB1s被认为是正向胁迫调节因子，但应特别关注它们潜在的负向调节作用。
