The Relation Ethylene Production To Senescence And Cloning Of The ACC Oxidase Genes From Lily

Lily flower is one of the five world famous fresh cut flowers, and is known widely by people for the characters of the big flower, variation flower color, graceful posture, and strong fragrant.The sales volum of fresh cut flower is considerable billion in the whole world. While lily flower blooming,it was the same as the other ones senescencing rapidly. How to prolong the longevity of lily flower was subject for studying rescently 20 years. Though many studies on the chemical keeping fresh were reported ,and were also effective to some degree, it had brought the negative effection on fresh cut flowers for producting toxic effect, leading to environment pollution, using inconveniently. The studies have provided a solid basis for inhibiting lily senescence by anti-sense RNA technology, studying the mechanism of lily senescencing, and cloning of its cDNA fragments of ACC oxidase genes.Liliun Asiatics "Elite" was classified 6 grades by the flower development degree of each grade .The each physiological index was determined ; The relationship of ethylene releasing and senescencing of the blooming flower was discussed; The mechanism of flower development and senescencing were analyzed. The total RNA of the flowers were extracted. The degenerate primers were designed by the consensus nucleotide sequences of ACC oxidase in GeneBank. The relative cDNA fragment of ACC oxidase genes were obtained by Reverse Transcriptase Polymerase Chain Reaction (RT-PCR) technology,and its homologs were also analyzed by sequencing and Blast retrieving. The results are as follows:l.The results showed that the vary of the flower respiratory intensity and ethylene releasing rate were increasing gradually in the late period. The variable tendency of them were showing no difference.2.With the lily flower development, Soluble protein content was decreasing, Cell membrane relative permeability was increasing strikingly; Unsaturated Fat Acid (luFA) were decreasing gradually; The MDA content was increasing; The peroxidase was increasing with the progress of flower senescencing; SOD was decreasing in the late period. 3.The relative analysis of the MDA content, membrance permeability, luFA, the ethylene releasing and respiratory rate showed that they had striking relation.4.The variable peak of ACC oxidase content appeared earlier than that of ethylene; The peak of ACC oxidase of Lilium Asiatics appeared on the forth and sixth periods.5.The system of the RT-PCR was founded in this experiment.6.The total RNA was extracted and purified using the sixth period flower of Lilium Asiatics 0"Pollyanna" and Lilium oriental "Sobanne".The ds-cDNA v/as synthesed by reverse transcriptase. The double degenerate primers were designed by the homologous sequence of the ACC oxidase genes. The cDNA fragments were obtained from Lilium Asiatics "Pollyanna" and Lilium oriental "Sobanne". The sequences data had submitted to GeneBank. The GeneBank accession number for Lilium oriental "Sobanne" is AY 656735 and Lilium Asiatics "Pollyanna" is AY 656736.7.The two sequencing and blast research results demonstrated that the homolog of the cDNA fragments of the ACC oxidase genes are over 80% by contrast with Tulipu.gesneriana, Psidium guajava, Phyllostachys edulis, Antirrhinum majus, Oryza sativa, Betula pendula.So, the cDNA fragments having obtained were confirmed the cDNA sequence of ACC oxidase genes...