Function Analysis Of Cotton Key Genes In Ethylene Synthesis Of Cell Elongation

Ethylene, as a plant hormone, playing a vital role throughout the life cycle of the plant, are widely effects in plant growth and development, such as seed germination, fruit ripening, leaf senescence, organ loss and response to stress reactions, etc.1-aminocyclopropane-1-carboxylic acid oxidase (ACO) gene, known as the ethylene forming enzyme (EFE), is the key enzyme in the last step of ethylene biosynthesis. Many studies have shown that the synthesis of ethylene within the cell play important regulatory role and is enhanced by promoting ethylene production capacity of plant stress tolerance.In recent years, a number of ACC oxidase (ACO) are continuously cloned from different plants, and the expression patterns have also been extensively studied, transgenic antisense plants showed significant inhibition of ethylene synthesis. Cotton is an important economic crop worldwide, stabilizing and improving the quality of cotton fiber has become the textile important competitiveness content in the international market. In this article,3 cotton ACO gene were cloned (ACO1, ACO2 and ACO3) from cotton fiber tissue, and their sequence alignment, physiological characteristics and functional analysis were performed. The results are as follows:1. By PCR, cDNA were amplified from the cotton fiber tissues, the length of the specific GhACO1, GhACO2, GhACO3 gene are 960,960 and 954 bp respectively. The ACO genes sequencing results showed that these 3 genes have high homology with Arabidopsis, tobacco, soybeans, mung beans, apples, cucumber.2. Constructed plant expression vector p35S::GhACO1, p35S::GhACO2 and p35S::GhACO3 was transformed to Arabidopsis thaliana and tobacco by floral dip and leaf disk method respectively; transgenic plants were obtained after selection by kanamycin and further PCR identifications. Homozygous transgenic Arabidopsis plants and transgenic tobacco are obtained.3. GUS histochemical analysis showed that, transgenic Arabidopsis leaves have a strong GUS activity, stems and roots have a little expression.4. Growth and development of adventitious were statistics in the T2 generation of transgenic Arabidopsis and tobacco plants, the results indicated that adventitious roots development was significantly promoted in transgenic arabidopsis and tobacco plants.5. T2 generation transgenic Arabidopsis plants were performed by salt and drought stress through NaCl and PEG6000, and the related physiological test results showed that compared with wild-type Arabidopsis, transgenic Arabidopsis displayed enhanced tolerance under salt and drought stress.6. T2 generation transgenic Arabidopsis plants were treated with low-temperature and high-temperature, and the related physiological test results showed that compared with wild-type Arabidopsis, transgenic Arabidopsis displayed enhanced tolerance under low temperature and high-temperature stress.