Characterization And Functional Analysis Of Plant Homeodomain (PHD) Transcription Factors Responsive To Abiotic Stress In Cotton

Object: Analysis expression of upland cotton (Gossypium hirsutum L.) PHD (planthomeodomain) transcription factor in different tissues of cotton and abiotic stressconditions, screening and cloning cotton Stress response gene. preliminary researchcotton response mode of plant homeodomain transcription factors under abioticconditions and abilities of resistance Stress of transgenic tobacco.Methods: According to information in the public database of plant transcriptionfactors, specific primer of the28EST sequences of cotton GhPHD genes weresynthesized. Using semi-quantitative RT-PCR method to detect the expression ofGhPHDs in the cotton seed, root, stem, leaf and fiber (15DPA) and the expressionpatterns under drought, high salt (the150mmol.L-1NaCl) and low temperature (4°C) abiotic stress. Using RACE technology to amplify end of5’ and3’ of theGhPHD1and stitching to obtain a full-length cDNA of the gene. Using the clonetechnology to clone the GhPHD6and GhPHD9. Connect the plant expression vector, Agrobacterium tumefaciens transformation infected the tobacco and obtainedtransgenic tobacco. Using chlorophyll fluorescence analyzer photosynthesis systemto determine the maximum photosynthetic production of transgenic tobacco, photosynthesis rate, proline and so on.Results: Expression of GhPHDs in various tissues displayed85.7%PHD geneexpressed in the seeds, roots, stems, leaves, fibers were57.1%,53.6%,46.4%,35.7%. Semi-quantitative RT-PCR analysis showed that17GhPHDs at least oneresponse to abiotic stress. GhPHD1responsed to drought, high salt and lowtemperature, GhPHD1, GhPHD10, GhPHD15, GhPHD16, GhPHD22, GhPHD25six genes involved in drought and high salt stress.GhPHD1, GhPHD8, GhPHD9andson an seven genes responsed to cold stress. RACE amplified the5’ end and3’ endof the GhPHD1were388bp and425bp. Splicing has been1396bp full-length cDNA. The the largest ORF of GhPHD1was978bp and cloned the full-length sequence ofGhPHD1. Cloned transgenic tobacco of GhPHD6and GhPHD9.13%PEG6000stress GhPHD6transgenic tobacco maximum photosynthetic production, proline, MDA content was significantly higher than the control wild-type tobacco.conductivity is lower than the wild-type tobacco.4°C low temperature, maximumphotosynthetic production of transgenic tobacco, proline, malondialdehyde andconductivity trend with the wild-type tobacco trend roughly similar, no significantdifference.Conclusion: Under abiotic stress conditions, there are differences expression ofGhPHDs in the seeds, roots, stems, leaves, fiber and other organizations the. In the seed the expression of GhPHDs were most(85.7%), in fiber were Minimum(35.7%). More than one gene is involved in more than two kinds of stress treatment,to show GhPHDs to adapt with different abiotic stresses or have similar function inthe upland cotton. Amplifiing GhPHD1gene5’ and3’ ends, obtaining the full lenthcDNA is1396bp. The physiological experiment results showed that GhPHD6transgenic tobacco had the initial drought resistance compared with the wild-typetobacco, and GhPHD9transgenic tobacco no significant cold resistance.