橡胶树品种‘湛试327-13’乙烯响应分子机制分析

Analysis of Ethylene Response Mechanism in Rubber Tree Variety'Zhanshi327-13'

橡胶树‘湛试327-13’新品种兼具抗寒和高产的特性,揭示其在乙烯刺激后的分子机制有利于精准鉴定和选育种质资源。本研究以1.5%乙烯利处理橡胶树‘湛试327-13’开割树为材料,利用荧光定量技术分析胶乳和树皮中活性氧淬灭酶、蔗糖转运蛋白和橡胶生物合成关键酶等基因的表达规律,结果表明:乙烯利处理并连续割6刀后,橡胶树活性氧淬灭酶、蔗糖转运蛋白、胶乳抗性和橡胶生物合成关键酶基因在树皮表达量高于其在胶乳中表达量。与对照相比,随着割胶刀数的增加,‘湛试327-13’树皮脂肪氧化酶(HbLOX1)和过氧化物酶基因(HbPOD1)基因表达显著上调,最高为22.15和31.95倍;蔗糖转运蛋白HbSUT1、HbSUT2a分别提高66.11和58.50倍;几丁质酶(HbCHI)、葡聚糖酶(HbGLU)和橡胶素(HbHEV)分别提高16.93、8.09和10.37倍;橡胶生物合成关键酶基因HbGGPPS和HbHMGS1分别提高了14.71和15.05倍。说明乙烯刺激橡胶树后,‘湛试327-13’胶乳和树皮中活性氧淬灭酶、蔗糖转运蛋白、胶乳抗性和橡胶生物合成关键酶基因依次高表达且持续时间长达6刀(18 d),是其抗寒性和产量形成的分子基础,亦可作为橡胶树种质资源评价指标用于分子辅助育种。

The new rubber tree variety‘Zhanshi327-13’has both characteristic of cold resistance and high yield,revealing the molecular mechanism of ethylene stimulation is conducive to accurate identification and breeding of germplasm resources.In this study,the gene expression patterns of active oxygen quenching enzymes,sucrose transporter and key enzymes of natural rubber biosynthesis in latex and bark were analyzed using 1.5% ethephon treated rubber tree‘Zhanshi327-13’.The results showed that after ethephon treatment and six consecutive tapping,the expression levels of active oxygen quenching enzymes,sucrose transport,latex resistance and key enzyme genes of rubber biosynthesis were higher in bark than in latex.Compared with the control,the expression of lipoxygenase(HbLOX1)and peroxidase gene(HbPOD1)in tree bark of‘Zhanshi 327-13’was significantly up-regulated along with the tapping time,and the highest expression was 22.15 and 31.95 times,respectively.Sucrose trans porter HbSUT1 and HbSUT2a increased 66.11 and 58.50 times,respectively.Chitinase(HbCHI),glucosidase(Hb-GLU)and latex allergen protein(HbHEV)were increased by 16.93,8.09 and 10.37 times,respectively.The key enzyme genes of rubber biosynthesis HbGGPPS and HbHMGS1 were increased by 14.71 and 15.05 times,respectively.These suggested that after ethylene stimulates,the active oxygen quenching enzyme,sucrose transport,latex resistance gene and rubber biosynthesis key enzyme genes were high expressed and lasts for up to six tapping(18 d)in latex and bark of‘Zhanshi327-13’.These are the molecular basis of its cold resistance and high yield formation,also can be used as rubber tree germplasm resources evaluation index in molecular assisted breeding practice.