生长素介导细胞分裂素(玉米素)调控杜鹃兰侧芽萌发  

Auxin Regulated Lateral Buds Germination in Cremastra appendiculata via the Regulation of Cytokinin(Zeatin)

作　　者：吕享[1] 叶睿华 田海露 吉宁[1] 刘思佳 张明生[1] LV Xiang;YE Rui-Hua;TIAN Hai-Lu;JI Ning;LIU Si-Jia;ZHANG Ming-Sheng(School of Life Sciences/State Engineering Technology Institute for Karst Desertification Control,Key Laboratory of Plant Resources Conservation and Germplasm Innovation in Mountainous Region（Ministry of Education）,Guizhou University,Guiyang 550025,China)

机构地区：[1]贵州大学生命科学学院/国家喀斯特石漠化防治工程技术研究中心/山地植物资源保护与种质创新教育部重点实验室,贵阳550025

出　　处：《农业生物技术学报》2018年第11期1872-1879,共8页Journal of Agricultural Biotechnology

基　　金：国家自然科学基金(No.81360613和No.81660627);国家重点研发计划课题(No.2016YFC0502604);贵州省科技计划重大专项课题(黔科合平台人才[2017]5411-06);国家喀斯特石漠化防治工程技术研究中心建设项目(No.2012FU125X13);贵州省科技创新人才团队建设专项资金(黔科合平台人才[2016]5624);贵州省教育厅创新群体重大研究项目(黔教合KY字[2016]023);贵州省研究生科研基金(黔教研合KYJJ字[2016]011);贵州大学国家级重点培育项目(黔科合平台人才[2017]5788)

摘　　要：杜鹃兰(Cremastra appendiculata)为多年生珍稀药用植物,自然条件下有性繁殖困难,营养繁殖因新生假鳞茎顶端抑制而不能有效进行"分枝"发育扩增假鳞茎,致使其繁殖系数极低。为探讨杜鹃兰假鳞茎成串生长的内在机制,本研究通过打顶及生长素运输抑制剂N-1-氨甲酰苯甲酸萘酯(N-1-naphthylphthalamic acid, NPA)和2,3,5-三碘苯甲酸(2,3,5-triiodibenzoic acid, TIBA)处理杜鹃兰假鳞茎,借此改变其内源植物激素水平以促进假鳞茎侧芽生长。研究结果表明,打顶及生长素运输抑制剂处理6 d后,侧芽内生长素水平显著降低(P<0.05),细胞分裂素水平则显著提高(P<0.05),且细胞分裂素水平的升高与显著上调细胞分裂素合成酶的关键基因—异戊烯基转移酶基因(isopentenyl transferase, IPT)的表达是一致的。处理40 d后,打顶、NPA和TIBA使二年生假鳞茎侧芽萌发率从0%分别提高到95%、85%和90%,以及三年生假鳞茎也分别提高到15%、76%和75%;处理90 d后,单株出苗数分别可达到对照的2.20、3.13和3.05倍。然而,外施玉米素(zeatin, ZT),仅使二年生和三年生假鳞茎萌发率提高至51%和35%,并未提高出苗率。可见,生长素可能通过调控IPT的表达,以此调控细胞分裂素水平,从而间接控制杜鹃兰侧芽的生长。本研究结果有助于提高杜鹃兰的繁殖系数,为地下茎顶端优势的理论研究提供了参考。Cremastra appendiculata is a perennial rare medicinal plant. Under natural conditions, it＇s hard to reproduce sexually, and the vegetative reproduction cannot effectively branch development to increase the number of pseudobulb due to apical inhibition of newborn pseudobulb. These factors lead to a very low breeding coefficient. Therefore, to explore internal mechanism of pseudobulbs growth in cluster, the pseudobulbs of C. appendiculata were treated by decapitation, auxin transport inhibitors N-1-naphthylphthalamic acid （NPA） and 2, 3, 5-triiodibenzoic acid （TIBA）. In this way, endogenous plant hormone levels might be changed to promote the growth of lateral buds of C. appendiculata. After decapitation and application of auxin transport inhibitors （NPA and TIBA） treated the pseudobulb of C. appendiculata for 6 days, the results showed that auxin levels in the lateral buds were significantly reduced （P〈0.05）, and cytokinin levels were obviously increased （P〈0.05）. The results of qRT-PCR showed that cytokinin levels increased because of rapidly up-regulated key genes of cytokinin synthetase （isopentenyl transferase, IPT） after treatments. After the decapitation, NPA and TIBA treating for 40 d, the germination rate of the biennial pseudobulbs in pseudobulbs string were increased from 0% to 95%, 85% and 90%, respectively, and the triennial pseudobulbs were increased from 0% to 15%, 76% and 75%, respectively. For the treatments of decapitation, NPA and TIBA, the number of seedlings per plant could reach to 2.20, 3.13 and 3.05 times of the control after 90 d, respectively. The application of zeatin promoted the germination of lateral buds of C. appendiculata in a certain extent （biennial： 51%; triennial： 35%）, but did not increase the rate of seedling emergence, which indicated that cytokinin promoted the germination of lateral buds, but could not promote to continued growth. The change of auxin levels was necessary for the continued growth of lateral buds. The results of this stud

关 键 词：杜鹃兰 生长素 细胞分裂素 侧芽 生长素运输抑制剂 

分 类 号：S184[农业科学—农业基础科学]