|DONG, CHAO - Nanjing Agricultural University|
|MA, YUANCHU - Jiangsu University|
|ZHENG, DAN - Nanjing Agricultural University|
|CHENG, ZONG-MING - University Of Tennessee|
Submitted to: Frontiers in Plant Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/11/2018
Publication Date: 5/29/2018
Citation: Dong, C., Ma, Y., Zheng, D., Wisniewski, M.E., Cheng, Z. 2018. Meta-analysis of the effect of overexpression of dehydration-responsive element binding family genes on temperature stress tolerance and related responses. Frontiers in Plant Science. https://doi.org/10.3389/fpls.2018.00713.
Interpretive Summary: There is a critical need to improve the stress tolerance of crops given the anticipated changes in climate and increases in population that are projected. Numerous studies have conducted genetic transformation of crop plants with the transcription factor, C-repeat/dehydration-responsive element binding factor (CBF), that upregulates the expression of many stress-responsive genes and increases stress tolerance to drought and low temperature. In a previous response we conducted a meta-analysis of the impact of CBF overexpression on drought tolerance. In the current study, we conducted a meta-analysis of the impact on CBF overexpression on freezing tolerance. The degree of response has varied between experiments and unwanted impacts on growth have been observed. There is a need to determine the impact of the overexpression of CBF genes on stress tolerance and other plant parameters across many independent experiments. There is also a need to determine how experimental variables, such as the source of the donor gene, the species of the recipient, the method of stress assessment, etc., impacts the overall effect of CBF overexpression on plant performance. The results of the meta-analysis clearly identified the impact of experimental variables on the effect of overexpression of a CBF transcription factor on a variety of physiological parameters and the overall effect of overexpression on freezing tolerance. These data can be used to optimize genetic transformation efforts to increase freezing tolerance and complements our previous analysis of the impact of DREB overexpression on drought tolerance and related physiological parameters.
Technical Abstract: C-repeat/dehydration-responsive element binding proteins are transcription factors that play a critical role in plant response to temperature stress. Over-expression of CBF/DREB genes has been demonstrated to enhance temperature stress tolerance. A series of physiological and biochemical modifications occur in a complex and integrated way when plants respond to temperature stress, which makes it difficult to assess the mechanism underlying the CBF/DREB enhancement of stress tolerance. A meta-analysis was statistically quantified in 75 published articles and was conducted to identify the overall influence of CBF/DREB on stress-related parameters in transgenic plants, and to determine how different experimental variables affect the impact of CBF/DREB over-expression. Seven of the 8 measured plant parameters were significantly (p= 0.05) modulated in transgenic plants when they were subjected to temperature stress, while 2 of the 8 parameters were significantly affected in non-stressed control plants. The measured parameters were modulated by 32% or more by various experimental variables, which include acclimated or non-acclimated, promoter type, stress time and severity, source of the donor gene, and whether the donor and recipient were the same genus. Further studies should be conducted under field conditions to better understand the role of CBF/DREB transcription factors in enhancing plant tolerance to temperature stress.