Functional Analysis Of Jasmonate Signal Pathway Genes,OsLOX4,OsAOS2 And OsLOX3 In Rice

Rice(Oryza sativa L.)is one of the world’s staple food,and rice production is concerned worldwide.However,due to pests and diseases,pathogenic microorganisms,floods,soil pollution and other causes,rice production is seriously reduced.Currently,the best solution is to use the resistance of rice itself,and plant resistance is regulated by a series of genes,so it is necessary to explore the resistant genes of plants.Plant hormones play irreplaceable roles in the growth and development of plants.Jasmonic acid signaling pathway plays key roles in plant defense/stress response,lipoxygenase(LOX)is the first key enzyme in the jasmonic acid synthesis pathway.Previous studies have shown that Allene oxide synthase(AOS)is associated with defense stress response,Jasmonic acid plays very important roles in seed germination,plant growth and resistance to pests and diseases.In this study,we chose jasmonic acid signal pathway related genes(OsLOX4,OsLOX3 and OsAOS2)as our research objects.We analyzed the upstream promoter sequence of the target genes.The promoter region of the OsAOS2 gene contained TC-rich repeats,which predicted that OsAOS2 was involved in the defense stress response.The OsLOX4 gene promoter contained wound-responsive element and may involve in salicylic acid,methyl jasmonate reaction.On the basis of these reason,the plant expression vectors of OsAOS2-OE and OsLOX4-OE were constructed and transformed by Agrobacterium tumefaciens.After tissue culture and screening,the positive transgenic rice were obtained.Moreover,the sub-cellular localization indicates that OsAOS2 may be located on the plasma membrane.In addition,after lox3 transgenic rice inoculated with rice blast fungus Guy11,the mutant shows more resistant to rice blast compared with that of wild type.While detecting the expression of related genes,we found that the expression levels of AOS2,PBZ1 and disease resistance related genes in mutant were significantly higher than those in the wild type,so we speculated that the silencing of OsLOX3 gene may improve the blast resistance of rice.Our results provide the fundamental materials and data for understanding the function of OsLOX4,OsLOX3 and OsAOS2.