Regulation Of Banana MuMADS2Transcription Fator On The Fruit Ripening And Quality

MADS-box gene family is a transcription factors which widespread in many plants. All the members contain a56-58amino acid domain called the MADS-box domain. Scientific research shows that the MADS-box gene family plays a key role in plants floral organ development, early or late flowering time, the regulation of fruit ripening and other aspects. The fruit which has important position in food value and economic value is an important organ of the plant reproductive development and also an important object of agricultural productionWe have already transformed a MADS-box gene named MuMADS2(Musa MADS-box gene) into the tomato and detected it by southern blot. The research focuses on the mrphological observation of the tomato fruit and measure a number of physiological indicators of red mature of tomato.Using the real-time fluorescence quantitative PCR analyzes the relative expression level of MuMADS2and the expression of ACO1, ACS2, CNR, E8and TAGL1in tomatoes. We also have detected five quality indicators content of amino acids,suger, lycopene,carotene and primary organic acids.Morphological observation of the tomato plant showed that the transgenic tomato plant are different with the WT in the plant size, fruit shape, seed number and pollen morphology et al. We have already had eight transgenic tomatoes which are varying degrees of short.The average height of transgenic plants was67.5cm, the control was125cm; transgenic fruit were smaller and lighter, average fruit weight was4.96g, control fruit weight6.33g. Transgenic fruit also have a less number of seeds, in which L53seeds were all abortion, L13and L56only had4seeds per fruit, the others were21seeds per fruit, the control was58seeds each fruit. Observation the morphology of tomato pollen with the scanning electron microscopy,L53were all shriveled and abortion, L13and L56pollen were dry sterility and had uneven surface, the pollens of L4, L12and L26were smooth and rounded, abortive pollen was less than L13and L56, but still greater than the wild type.RNA extracted from above fruits was reverse transcribed to cDNA. The expression of MuMADS2was detected by fluorescent quantitative PCR technique in eight transgenic strains fruits at different developmental midterm(immature green(IGM), green mature(GM), breaker fruit(BR), red mature(RM),), among of them, fruits of5transgenic strains(L4、L12、L13、L26andL56) had higher expression levels. And expression peak of MuMADS2Appeared in the green mature stage(GM), followed by BR, IGM and RM were lowest. Selecting five strains which had higher expression level of MuMADS2in the fruits, fluorescence quantitative PCR was used to analyze the expression of seven mature, and quality-related gene(ACO1, ACS2, CNR, E8, PG, PSY1and TAGL1) in the fruit, the results is the expression levels of7gene of L4, L12, L26strains become the largest in BR. But only ACO1,ACS2, and TAGL1of L13and L56strains appeared maximum expression level in BR. The expression of7mature, and quality-related genes of Wild-type in BR showed maximum. Absolute expression level showed, the expression of seven transgenic tomato maturity and quality related genes higher than the wild type.RNA reverse transcription cDNA fruit extract above, the use of fluorescent quantitative PCR MuMADS28transgenic plants fruit at different developmental stages (young fruit stage (immature green, of IGM), the green mature stage (green mature, GM), turn the color of(breaker fruit, BR) and red ripe (red mature, RM)) expression, higher expression levels in five strains of L4, L12, L13, L26and L56fruit. And MuMADS2peak expression in the green mature stage, turn the color of followed by the red ripe stage, and young fruit of the lowest. High five lines MuMADS2expression in selected fruit, fluorescence quantitative PCR analysis of AC01, ACS2, CNR, E8, PG, PSY1and TAGL1seven mature, and quality-related gene expression in the fruit, the results of L4, L12, L26lines7gene expression in the color change of the largest, L13and L56only ACO1, ACS2, and TAGL1maximum expression level in turn the color of the wild-type7mature, and quality-related gene in the color changing of the expression of. Absolute expression level, seven of the transgenic tomato maturity and quality related genes than the wild type.The ethylene production of the tomato fruit showed that the24th,26th,13th and4th have a peak on breaker fruit and then decreased,moreover the ethylene production was higher than AV-6except4th. Through the different stages of maturation time statistics showed that24th,26th and13th spent2-4days less time then AV-6.All results above are consistent with the ripening-related gene expression analysis and conclud that MuMADS2can regulate ripening time and ethylene production of tomato fruit. The function of the MADS-box gene family in plants has been certain in floral organ development, early or late flowering time and regulation of fruit ripening,but the function in change fruit quality has been little reported. We had detected the fruit quality of all the Transgenic plants. The results showed that all transgenic plants fruit have high level of amino acids, lycopene, carotene, sugar and organic acids.PSYl (phytoene synthase gene), the relative expression levels was higher in red mature of the24th,13th,26th and4th which was match with the result of the determination of the fruit quality. Therefore, we hypothesized that transgene the banana MuMADS2into tomato could affected the tomato fruit quality, and upregulated PSY1genes to improved the content of carotenoids in the transgenic tomato fruit.The gene expression of PG was higher than AV-6in breaker fruit of4th,24th and26th. And measuring the hardness of the tomato fruit, found that fruit of4th was softening two times than the wild-type,the24th and26th were followed which were the further evidence of the PG gene expression analysis results. Description MuMADS2expression can be modulated by PG which affects fruit firmness.The tomato plant morphology observation showed that the4th had the biggest shape and weight,the12th and the13th were smallest and others were no significant difference between wild-type.Observation the morphology of tomato’s pollen useing electron microscopy found that13th and56th’were more shriveled, abortion and coarse in addition had less seeds. On the other sides4th,24th and the26th were smooth rounded,had a little number of abortive pollen which the pollen size was larger than wild type and also had more seeds but less zhan wild type.Combine with field plants shape of the two kinds of tomatos concluded that the MuMADS2inserted into different sites and copy number cause the two types of pollen.