Chromosomal Localization Of Transcription Factors In Gossypium Hisutum

Cotton (Gossypium spp.) is the world’s most important natural fiber crops. The genus Gossypium comprises approximately 45 diploid and 5 tetraploid species, including 4 cultivated species, G. arboreum, G. herbaceum, G. hirsutum and G. barbadense, which produce textile fiber. Of the cultivated species, G. hirsutum supplies over 95% of the world’s total fiber production.China is not only a major cotton producing country, but also a major cotton consuming country. Cotton has an extremely important position in the national economy. The unique feature of absorbing moisture, aeration, soft and static electricity exception are loved by people more and more, and the demand for cotton is growing day by day. However, cotton growth and yield are limited by biotic or abiotic stress, such as hypothermia, drought, salinity, pests and diseases. Transcription factors play a very important role in pant growth, stress response process and adversity defensing procedure.Transcription factor (TF) is also called trans-acting factor which can specificly bind with the cis-acting factor in the promoter region, interact with other protein that regulate gene expression intensity and even control the spatial and temporal specificity of gene expression, and response to hormone stimulation and the external environment stress. To improve crop yield, quanlity and resistance to stress in molecular breeding, compared to transfering or modifying an individual functional gene, transfering or modifying a transcription factor is more effective. Manipulation of a transcription factor can prompt numbers of functional genes to play a role, so as to achieve access to comprehensive improvement of plant traits. Chromosomal localization of transcription factor has a great significance to understand the distribution characteristics of transcription factor, the accurate gene structure, function and evolution.The present study designed SSR primer according to Gossypium hirsutum transcription factor DNA sequences in Plant Transcription Factor Databases (PTFD) and Gossypium MYB transcription factor DNA sequences in National Center for Biotechnology Information (NCBI), and mapped the polymorphic SSR in upland cotton. The results can increase the cotton genetic mapping markers, and lay the foundation for further resolving the role of transcription factors in the cotton yield, fiber quality and stress tolerance. The results are as following:1 Primer polymorphismA total of 1592 SSR primer pairs designed from 1116 Gossypium hirsutum transcription factor DNA sequences in PTFD and 65 transcription factor DNA sequences in NCBI were used to screen the polymorphic primers between upland cotton cultivars/lines Yumian 1,7235, CCRI35 and T586. A total of 74 pairs of polymorphic primers were obtained, accounting for 4.6% of the total primer pairs. The polymorphic primers included 25 polymorphic primers between Yumian 1 and CRI 35,33 between Yumian 1 and T586, 36 between Yumian 1 and 7235, accounting for 1.6%,2.1% and 2.3% of the total primers, respectively. Seventy-four pairs of polymorphic primers cover 69 transcription factors of the 26 transcription factor families.2 Genotyping RIL populationsThree recombinant inbred line populations were genotyped with the primer pairs showing polymorphism between two parents and 101 polymorphic loci were detected. Among them, 25 primer pairs obtained 25 loci in population (Yumian1×CRI35),36 primer pairs obtained 41 loci in population (Yumian1×7235), and 33 primer pairs obtained 35 loci in population (Yumianl×T586).3 Localizing transcription factorsThe 101 transcription factor SSR loci, together with other SSR loci mapped on upland cotton linkage map in our laboratory, were used to conduct on genetic linkage analysis, and 92 loci were mapped on 23 chromosomes. Twenty-three of 25 loci were mapped on chromosome in population (Yumian 1×CRI35) population,30 of 35 loci were mapped on chromosome in population (Yumian 1×T586), and 39 of 41 loci were mapped in population (Yumian 1×7235). 4 Distribution of transcription factor genesThe mapped 26 transcription factor families included 69 members, and involved one to 19 members from each family. A total of 92 loci were mapped on 23 chromosomes, including 32 loci cotton A-genome and 60 on D-genome from tetraploid cotton.