The CmLOX10 Gene Functions In Maturation,Senescence And Drought Response In Oriental Melon (Cucumis Melo Var.Makuwa Makino)

Oriental melon(Cucumis melo var.makuwa Makino)is the one of main economic crop which develops rapidly recently.But there are always various stresses to bring about the yield and quality reduction,during the growth and development of oriental melon.Lipoxygenase(LOX)had a key role in stress resistance,and LOX is divided into 9-LOX and 13-LOX,according to the oxygenated site.It is believed that 13-LOX responses to the abiotic stresses,previous research group's studies found that the promoter of CmLOX10 have elements that response to abiotic stresses,such as drought stress.However the role of CmLOX10 gene in response mechanism of drought stresss is remain unclear.Recently,transient expression technology and virus-induced gene silencing have been rapid and efficient method to analyze gene function.And therefore,in the paper,the oriental melon inbred line “M1-23” as material,establishing Agrobacterium-mediated transient over-expression system and Tobacco Rattle Virus(pTRV)-based VIGS in oriental melon,which the maker gene is phytoene desaturase in oriental melon,and CmLOX10 is the target gene.VIGS was established in oriental melon firstly,and the results revealed preliminarily that CmLOX10 has a vital role in maturation,senescence and drought stress response.The main results are as follows:1.The over-expression vector of CmLOX10 was constructed by double digests method,following the Agrobacterium-mediated transient expression method in oriental melon.The transient over-expression system is established excellently in oriental melon by gene expression analysis and fluorescence imaging detection in vivo.DAB and trypan blue staining found that the leave color is darker than the empty vector,the electrolyte leakage and MDA content were higher,furthermore,the expression of CmAOS and CmHPL which the LOX downstream pathway,were increased significantly,it suggested that CmLOX10 gene over-expression can accelerate the maturation and senescence,CmLOX10 gene can involved in stress in oriental melon.2.The VIGS vectors of CmLOX10 and CmPDS were constructed by double digests method firstly,following the seed absorption method,and confirming establishment VIGS in oriental melon firstly by CmPDS gene expression analysis and fluorescence imaging detection in vivo.It was found that the target gene CmLOX10 expression was decreased,and the gene expression CmAOS and CmHPL were declined in silencing plants.In other words,CmLOX10 gene can play a key role on stress in oriental melon.3.In this,CmLOX10 gene silencing oriental melon plants were conducted by withholding water for 12 d,to determine the role of CmLOX10 gene in drought stress response in oriental melon.We found that the drought resistance was weaker in CmLOX10 gene silencing by the analysis of phenotype,relative water content and proline content.And then the determination of MDA content,electrolyte leakage,DAB and trypan blue staining,revealing that CmLOX10 gene silencing aggravated cell membrane damage,the accumulation of reactive oxygen species and increasing cell death in the oriental melon leaves.It was found that the lipid peroxidation may be induced by non-enzymatic lipid peroxidation in drought stress of oriental melon.The expression of CmAOS was decreased significantly in drought stress,and JA contents decreased significantly in silencing plants indicated that CmLOX10 gene regulated the drought resistance by JA pathway in oriental melon.In conclusion,the transient expression and VIGS approach were constructed excellently in oriental melon.And CmLOX10 gene plays a critical role on maturation and senescence and drought stress,which was regulated by JA pathway in the oriental melon.In this paper,the establishment of VIGS technology by seed absorption method provides an excellent tool to exploit gene function in melon.