不同耐寒品种橡胶树ICE与CBF基因对低温胁迫的表达差异

Expression Differences of ICE and CBF Genes in Different Cold-tolerant Rubber Tree Varieties under Low Temperature Stress

本研究从耐寒基因的转录因子方面对橡胶耐寒品种(热研7-33-97)和不耐寒品种(热研7-20-59)进行研究。分别进行短期(1 d)和长期(7 d)冷处理后测定脯氨酸、丙二醛、电导率、超氧化物歧化酶等生理指标及HbICE1、HbCBF1、HbCBF2和HbCBF3的表达水平。结果表明,脯氨酸7 d积累量基本一致,但1~7 d积累过程明显不同,丙二醛1~7 d积累量增长趋势相反,不耐寒品种(热研7-20-59)在第1天时达到最大,随后逐渐下降,而耐寒品种(热研7-33-97)丙二醛的积累量持续上升。而电导率和超氧化物歧化酶1~7 d变化趋势基本一致;两个品种的橡胶转录因子表达趋势相同,在短期处理后表达量都会迅速增加,12 h时达到最大,随后在长期处理中,HbCBF1和HbCBF2的表达量逐渐下降,HbCBF3则维持高表达至7 d。而HbICE1的相对表达量则出现不同的趋势。同时‘热研7-33-97’HbCBF基因的相对表达量高于‘热研7-20-59’,且表达差异显著。本研究利用不同耐寒品种研究ICE与CBF基因对低温胁迫的响应表达差异,为进一步探索橡胶树低温寒害响应机制提供参考和依据。

In this study, co ld-tolerant rubber variety(Reyan 7-33-97) and non-cold-tolerant variety(Reyan 7-20-59) were studied in terms of transcription factors of cold tolerance genes. After short-term(1 d) and long-term(7 d) cold treatment, physiological indicators such as proline, malondialdehyde, electrical conductivity, superoxide dismutase and the expression levels of HbICE1, HbCBF1, HbCBF2 and HbCBF3 were measured. The results showed that the accumulation of proline on 7 d was basically the same, but the accumulation process of 1~7 d was obviously different, and the accumulation of malondialdehyde from 1~7 d increased in the opposite direction. The accumulation of malondialdehyde in non-cold-tolerant variety(Reyan 7-20-59) reached the maximum on the first day and then gradually decreased, while that in cold-tolerant variety(Reyan 7-33-97) continued to increase. The electrical conductivity and superoxide dismutase 1~7 d change trends were basically the same;the expression trends of the rubber transcription factors of the two varieties were the same, and the expression levels increased rapidly after short-term treatment, reached the maximum at 12 hours. Then in long-term treatment, the expression levels of HbCBF1 and HbCBF2 gradually decreased, while the expression of HbCBF3 remained high until 7 days. The relative expression of HbICE1 showed different trends. At the same time, the relative expression of HbCBF gene in’Reyan 7-33-97’ was higher than that in ’Reyan 7-20-59’, and the expression difference was significant. In this study, different cold-tolerant varieties were used to study the differences in the expression of ICE and CBF genes in response to low temperature stress, and to provide a reference and basis for further exploring the response mechanism of rubber trees to low temperature and cold damage.