Effect Of IaaM On The Anatomical Structure Of Pigment Glands,Gossypol Metabolism,and Their Gene Expressions In The Upland Cotton

Genetic engineering technology has been the general technology of crop variety improvement.IF 11 is a transgenic cotton material with iaaM gene which by producing tryptophan monooxygenase to increase the contents of IAA in ovule,improving the lint percentage and micronaire value at the same time.The study of our lab found that contents of IAA had improved significantly in the different organs of IF 11 material.The exogenous gene or increasing of IAA dramatically affected the gossypol metabolism in IF11,reduced the storage capacity of gossypol.In order to investigate the effects of iaaM on pigment glands size,pigment glands density and contents of(-)/(+)-gossypol in the different organs and the effects of iaaM gene on the gene expression of pigment glands formation and gossypol synthesis in various organs,so this study used IF11 and its genetic background material,Jimian 14.The main results were as follows:(1)Systematically compared pigment gland density and size,(-)-gossypol contents,(+)-gossypol contents and total gossypol contents in different organs of IF11 and its genetic background material Jimian 14.The results showed that pigment glands density and size in most parts of IF 11 were smaller than Jimian 14,but except middle leaf.Total gossypol contents of IF 11 were less than Jimian 14 in most organs,(-)-gossypol contents were less than Jimian 14,but(+)-gossypol contents were higher than Jimian 14.The results illustrated that decrease of pigment glands and gossypol contents in IF11 was related to the insertion of iaaM gene and up-regulation of IAA.The up-regulation of IAA may affect the anatomical structure of pigment glands and gossypol synthesis.(2)Systematically observed pigment glands density and size and tested(-)/(+)-gossypol contents in the different tissues of 6 upland cotton.The results illustrated that glandless cotton whole plant without pigment glands,while there were significant differences in pigment glands of glanded cotton.The pigment glands density of seed was the largest and the pigment glands density of bract was the smallest.The pigment glands size of boll shell was the largest and the pigment glands size of petal and seed were the smallest.In glanded cotton,the total gossypol contents of seed were the largest(0.8823%?1.2371%),(-)-gossypol for 37.90%?49.68%,the total gossypol contents of bract were the smallest(0.0271%?0.0335%).The organs of glandless cotton had a certain amount of(-)/(+)-gossypol,but contents was significantly lower than glanded cotton,and the total gossypol contents of seed was only 0.011%.(3)Systematically analyzed correlation among pigment glands,(-)/(+)-gossypol contents in each parts of 6 upland cotton.The results illustrated that there were significant negative correlation between density and size of glands in glanded cotton.There were significant positive correlation between total gossypol contents and(-)/(+)-gossypol contents,likewise(+)-Gossypol contents and(-)-gossypol contents.Density of the glands was positively correlated with total gossypol contents and(-)/(+)-gossypol contents.Size of the glands was negatively correlated with(+)-gossypol contents,and the size of the glands was no significant correlation with(-)-gossypol contents and total gossypol contents.There was high correlation of total gossypol contents between seed and petal,so we can use gossypol contents of petal to analyze the gossypol contents of seed.(4)Systematically analyzed the gene expression of pigment glands formation and gossypol synthesis in IF11 and Jimian 14 by using the fluorescent quantitative PCR technology.The results illustrated that the relative expression of pigment glands formation gene GoPGF in the most parts of IF11 were the largest.The relative expression of gossypol synthesis gene HMG1 and HMG2 in root of IF 11 and Jimian 14 showed little difference.The relative expression of CYP706B1,GhCPRl and GhCPR2 in root of IF 11 was significantly lower than Jimian 14.This showed that the insertion of iaaM gene did not affect the formation of glands but affect the synthesis of gossypol in root,which leading to the decrease of gossypol contents in IF11.