冷冻胁迫下毛竹叶绿素荧光参数变化及抗寒相关转录因子表达

Changes of chlorophyll fluorescence parameters and expression of cold-related transcription factors in Phyllostachys pubescens seedings under chilling and freezing stress

研究短时冷冻胁迫条件下叶绿素荧光参数和抗寒相关转录因子的表达水平变化,探讨毛竹抵抗冷冻胁迫的机制。以生长90 d的毛竹实生苗为材料,人工模拟短时间(15,30,60,90 min)冷害(4℃)、冻害(-5、-10℃)胁迫,测定叶片的叶绿素荧光参数和抗寒相关转录因子(PeMYB、PeWRKY10、PeCBF1、PeDREB1)的表达水平。结果表明,冷害和冻害均能对毛竹叶片光系统Ⅱ(PSⅡ)活性中心造成损伤,4与-5℃短时间胁迫,对PSⅡ的损伤是可逆的,而-10℃造成的损伤是不可逆的。相关性分析结果表明,冷冻胁迫条件下,转录因子PeMYB和PeWRKY10与各叶绿素荧光参数呈负相关关系,PeCBF1和PeDREB1与各叶绿素荧光参数呈正相关关系。

The author made a research on the changes of expression level of chlorophyll fluorescence parameters and cold-related transcription factors under the short period of chilling and freezing stress and discussed the mechanism of Phyllostachys pubescens resisting to chilling and freezing stress. Taking the seedlings of P. pubescens with 90 days as material, under the short period （ 15, 30, 60, 90 min） of chilling （4 ℃ ） and freezing （ -5, - 10 ℃ ） stress handled by manual simulation, the author monitored expression level of leaf chlorophyll fluorescence parameters and its cold-related transcription factors, including PeMYB, PeWRKYIO, PeCBF1, PeDREBI. The results showed that both chilling and freezing stress could cause damage to PS H activity centre of P. pubescens leaf. Moreover, the damage to photosynthetic system caused by the stress of low temperature （4 and -5 ℃ ） on a short period was reversible, while the damage caused by - 10 ℃ was irreversible. Correlation analysis showed that under the situation of chilling and freezing stress, PeMYB and PeWRKYIO were negatively correlated with each chlorophyll fluorescence parameter, while PeCBF1 and PeDREB1 were positively correlated with it.