Quantitative ExPression Analysis Of Genes Related To Leaf Senescence Of Banana

Banana (Musa) is one of the most important economical crops in Hainan Province. Leaf premature senility can seriously impact on the banana quality and production. Plant senescence is tightly associated with the senescence genes.This study was aimed at probing the molecule mechanism of leaf senescence, for remoulding the banana leaf senescence genes, and acquiring high quality banana species. The3-month old banana leaves and isolated leaves were treated by darkness and6-BA. The expression of hormone, invertase, and leaf senescence related genes were measured by real-time fluorescence quantitative PCR in different leaf senescence development stages.The main results showed as follows:(1) The expression of AK107043, CTR1, INCW1, INCW2, SAG12,SAG19were upregulated, while OsRR2, OsRR4, OsRR6, CKX11, AY187620, AK070682, CB667155, OSTMK, OsGA2oX3genes were downregulated after treatment with darkness, which showed that Abscisic acid, ethylene might have positive regulation in leaf senescence, whereas, cytokine, auxin and gibberellin might have negative regulation.(2) The expression of OsRR2, OsRR4, OsRR6, CKX11, AY187620, AK070682, CB667155, OSTMK, OsGA2oX3were upregulated, and AK107043, CTR1, INCW1, INCW2SAG12, SAG19genes were downregulated after treatment with6-BA, revealed thant Abscisic acid, ethylene might have negative regulation in leaf senescence, whereas, cytokine, auxin and gibberellin might have positive regulation in the process leaf senescence.(3) Different genes had different sensibility for environment or hormone treatment. Darkness treatment had stronger impact on the expression of OsRR4,CKX11, AY187620, AK070682, OSTMK, INCW1, SAG12,SAG19than6-BA, whereas, OsGA20X3was mainly regulated by6-BA. The expression of OsRR2, OsRR6, Y187620, INCW2were obviously influenced by darkness on the first stage, then by6-BA on the later stage.(4) INCW series cell wall inverse genes and SAG genes were higher expression than hormone related genes, especially SAGs genes. It revealed that INCW and SAGs series genes were important banana leaf senescence genes. When the INCW series genes expression rose, SAGs began to express highly. INCW series may initiate leaf senescence.