Molecular Cloning, Expression Analysis Of CONSTANS-like Genes In Cotton

Cotton is a kind of major crop, and cotton fiber provides an important material for the textileindustry and medicine field. The contradiction between large amount of people and small area offarmland as well as the conflict between grain and cotton for land is more and more serious. Precociousvariety is a effective way to solve this conflict. Flower development was the key developmental stagefor higher plants, transforming from vegetative growth to reproductive growth and realizing alternationof generation. As a comprehensive developmental process, flowering of plants includes floweringinduction, signal transduction, flowering determination and organogenesis, and involves in convertingof different developmental ways. The establishment of spatial and temporal expression pattern offlowering time gene and signal transduction mechanism between intracellular and intercellular playedan important role in this process. The cotton flower development as well as blooming date was closelyrelated to the cotton earliness. Through using gene CO and its family gene COL which was critical inthe photoperiod signaling pathway during Arabidopsis flower development for reference, this researchmainly focused on isolating gene GhCOL that was playing a key role in cotton flower development andthen identifying its function, These results will provide genetics basis for early maturity cotton breeding.The main contents were as follows:1. By screening in NCBI database and the normalized, full–length cDNA library generated fromupland cotton flower development by our laboratory,48ESTs were obtained and then assembled5full-length genes which were verified by sequencing.2. Evolutionary tree of CONSTANS-like protein sequence was constructed among Gossypiumhirsutum, Populus, Oryza.sativa, Zea mays and arabidopsis thaliana.3. The expression profiling of CONSTANS-like genes in fiber, roots, stems, leaves, flowers and seedsof the precocious variety CCRI36was carried out by the quantitative real–time PCR. The resultindicated that the expression of CONSTANS-like genes were relatively high in cotton leaves.4. The different time expression pattern of these genes in treated leaves with photoperiod wasexamined. The result indicated that GhCOL5had significant photoperiodism, and GhCOL5showedlow expression in the daytime and a high peak in the night, which was similar to the expression patternof AtCO.5. The expression vectors of these genes were constructed.