Cloning Of β-Galactosidase In Some Stone Fruit-trees And Papaya

β- galactosidase is the only enzyme that has been shown to cleave the β-(1→4)-galactan bond directly and produce galactosyl residues from the cell wall during fruit ripening, which relates to the softening of many fruits. In the present study ,based on the optimization of the genomic DNA and total RNA extraction methods, the writer has cloned the cDNA or genomic DNA fragments of β- galactosidase gene from the leaves or fruits of Tai wan sweet peach, plum, mume, nai and papaya(zhang hong) in Fujian. The main results were as following:1.The methods for extracting genomic DNA and total RNA from the leaves and pulps of peach, plum, mume, nai and papaya were modified. The pure and intact samples of genomic DNA and total RNA were obtained by modifying the traditional method of CTAB and TriZoL method for the successive PCR amplification or RT-PCR reactions.2.Two PCR primers were designed based on the conserved cDNA sequence of β- galactosidase from apple. With the technology of PCR, we have cloned the DNA fragments in peach, plum, mume and nai. Their sequence longthes are 1388 bp, 1388 bp, 1389 bp and 1389 bp, and their nucleic acid homology is 98.90%. With the technology of RT-PCR and the same primers, We also have cloned an 862 bp long cDNA fragment containing 263 amino acids in peach young fruits. Comparisons between the β- galactosidase sequence from Malus domestica, Pyrus pyrifolia, Pyrus...