摘要
乌蒙宽叶杜鹃(Rhododendron sphaeroblastum var.wumengense)是高海拔耐寒植物,基于课题组前期从其转录组中筛选,发现MYBS3和稀有冷诱导2(rare cold inducible 2,RCI2)基因在增强植物耐冷胁迫中作用显著.本研究克隆出2个乌蒙宽叶杜鹃中调控耐寒的关键转录因子基因,分别命名为RsMYBS3(GenBank No.OR178946)和RsRCI2B(GenBank No.OR178945),其cDNA全长分别为795和165 bp,分别编码氨基酸数量为264和54 aa.生物信息学分析表明,RsMYBS3为亲水性不稳定蛋白,具有SANT超家族典型的SANT保守结构域;RsRCI2B为疏水性稳定蛋白,具有RCI2基因家族典型的PMP3高度保守结构域.基因同源性比对结果显示,RsMYBS3和RsRCI2B蛋白均与红马银花(Rhododendron vialii)中的MYBS3和RCI2B蛋白同源性较高,分别为93.73%和94.44%;系统进化分析发现,RsMYBS3和RsRCI2B均与红马银花RvMYBS3和RvRCI2B聚为一支,推测四者为直系同源关系.qPCR分析表明,低温胁迫下,2个基因在乌蒙宽叶杜鹃中均有显著表达,但在不同胁迫温度和时间下表达模式不同,其中RsMYBS3基因在-6℃处理1d时表达量最高,随着胁迫时间延长,4 d时表达逐渐下调,7 d表达又逐渐上升;在-12℃处理1～4 d时表达量逐渐上升并达到峰值,7 d时表达逐渐下调;而RsRCI2B基因在-6℃处理1～7 d时表达均逐渐上升,在-12℃处理下除1d时表达略有下调外,随着胁迫时间延长,4～7 d时表达量逐渐上升并达到峰值.上述结果推测,RsMYBS3和RsRCI2B基因可能参与了乌蒙宽叶杜鹃的耐寒响应生理过程.本研究为后续进一步探讨其耐寒分子机制提供了基础数据和理论依据.
Abstract
Rhododendron sphaeroblastum var.wumengense is a high-altitude and cold-tolerant plant.MYBS3 and rare cold inducible 2(RCI2B)genes were found to play a significant role in enhancing cold stress tolerance in plants based on the pre-screening from R.sphaeroblastum transcriptome.In this study,the key transcription factors RsMYBS3(GenBank No.OR178946)and RsRCI2B(GenBank No.OR178945)genes that regulated cold tolerance of R.sphaeroblastum were cloned,whose cDNA lengths were 795 and 165 bp,encoding 264 and 54 aa,respectively.Bioinformatics analysis showed that RsMYBS3 was a hydrophilic unstable protein with a typical SANT conserved structural domain of the SANT superfamilies;RsRCI2B was a hydrophobic stable protein with a highly conservative structural domain typical PMP3.The results of gene homology comparison showed that both RsMYBS3 and RsRCI2B proteins were highly homologous to MYBS3 and RCI2B proteins in red horse psyllium(Rhododendron vialii).The similarities were 93.73%and 94.44%,respectively.Phylogenetic analysis showed that RsMYBS3 and RsRCI2B were clustered in a clade with RvMYBS3 and RvRCI2B from R.vialii,which suggested that 4 genes were orthologous.qPCR analysis showed that both genes were significantly expressed in R.sphaeroblastum under the low-temperature stress,but had different expression patterns under different stress temperatures and times.The RsMYBS3 gene had the highest expression level at-6℃treatment on 1 d,and then gradually decreased on 4 d with the prolonging of stress time,and expression gradually up-regulated on 7 d.The expression level gradually increased and reached a peak from 1 d to 4 d,and gradually decreased on 7 d under the-12℃treatment.While the expression level of RsRCI2B gene had gradually increased from 1 d to the 7 day at-6℃treatment,and at-12℃treatment,except for the slight decrease expression on 1 d,the expression level gradually increased and reached a peak from 4 d to 7 d as the stress time prolonged.The above mentioned results suggested that both RsMYBS3 and RsRCI2B genes might be involved in the cold-tolerance-response physiological process of R.sphaeroblastum.This study provides some certain basic data and theoretical basis for exploring their cold tolerance molecular mechanism in the future.
基金项目
国家自然科学基金(32060364)
国家自然科学基金(32060366)
云南省重大科技专项(202102AE090052)
云南省园林植物遗传改良与高效繁育博士生导师团队(503210103)
国家科技期刊平台
NSTL
万方数据