低温胁迫下转RdreB1BI草莓逆境相关基因表达及抗性评价

Expression of Abiotic Stress-related Genes and Resistance Evaluation in RdreB1BI Transgenic Strawberry Lines Under Cold Stress

为研究低温胁迫处理后,草莓逆境相关基因的表达及生理指标的变化,并对转RdreB1BI草莓进行抗性评价,本研究以已经通过分子鉴定的红颜草莓转RdreB1BI基因株系为试验材料,分析了零上冷害(4、2和0℃)、零下冻害(-2、-4和-6℃)以及常温(25℃),共7个温度梯度处理下草莓叶片丙二醛(MDA)含量、渗透调节物含量(可溶性糖、可溶性蛋白)、过氧化氢酶(CAT)、超氧化物歧化酶(SOD)及过氧化物酶(POD)活性,并采用RT-qPCR法分析了在常温、-2℃和-4℃处理下草莓叶片外源RdreB1BI基因及内源逆境相关基因的表达情况。结果表明,株系7、株系8和株系10叶片在-4℃和-6℃处理无明显黄叶褐化现象,叶片SOD活性显著高于对照、株系1和株系9;株系10在-4℃和-6℃处理下叶片可溶性糖含量显著高于对照、株系1和株系7;-6℃处理下株系8叶片CAT活性保持较高水平。在-4℃处理下,ZAT10在株系7和株系8中的表达量显著高于株系1、株系9、株系10和对照,NAC在株系8和株系10中的表达量显著高于株系1、株系7、株系9和对照,表明转基因株系中,株系7、株系8和株系10具有较强的抗寒性。此外,在-4℃处理下,转RdreB1BI草莓中IDD4、PP2C25、HSFC1a及MYBR等转录因子的表达量显著高于对照,能协同RdreB1BI基因参与逆境胁迫响应,提高保护酶活性及渗透调节物质的含量,调控草莓对低温的耐性。外源RdreB1BI基因转入后能明显提高草莓的抗寒性。本研究结果为红颜草莓低温调控机理、北移栽培及抗性育种研究提供了理论基础。

To study the expression of genes involved in biotic stress and its physio-chemical reponse under cold stress,and to evaluate the resistance of RdreBIBI transgenic lines,the rd29 A： RdreBIBI transgenic Benihoppe strawberry Lines were used as material. The content of malondialdehyde（ MDA） and osmotic regulator,the activity of peroxidase（ POD）,superoxide dismutase（ SOD） and catalase（ CAT） under a total seven temperature gradient treatments（ 25℃,4℃,2℃,0℃,-2℃,-4℃ and-6℃） were analyzed. The expression of RdreB1 BI and endogenous stress-related genes in strawberry leaves under normal temperature,-2℃ and-4℃ were analyzed by RT-qPCR. The results showed that the transgenic line 7,8 and 10 had no obvious yellowing leaves under-4℃ and-6℃ treatment,and the SOD activity in leaves was significantly higher than the control,lines 1 and 9. The soluble sugar content in leaves of transgenic line 10 under-4℃ and-6℃ treatment was significantly higher than control,line 1 and 7. The activity of CAT in leaves of line 8 under-6℃ treatment kept a high level. The expression levels of ZAT10 in line 7 and 8 under-4℃ treatment were significantly higher than line 1,9,10 and control; The expression levels of NAC in line 8 and 10 under-4℃ treatment were significantly higher than line 1,7,9 and the control,It illustrated that the line 7,8 and 10 had stronger cold resistance than other lines. Further analysis showed that the expression levels of transcription factors such as IDD4,PP2 C25,HSFC1 a and MYBR in transgenic plants under-4℃ treatment were significantly higher than control group. They cooperated with RdreB1 BI gene involved in signal transduction of stress response,improved protective enzyme activity and osmolytes contents,and regulated strawberry cold resistant. It illustrated that the insertion of the exogenous RdreB1 BI gene can significantly improve the strawberry cold resistant. This study provides a theoretical basis for the mechanism of low-temperature regulation of Benihoppe strawberry,the research of northward transplanting and resistant breeding.