Cloning Of PGIP Gene From Prunus Mume Sieb Et Zucc. 'Longyan Mei', P.salicina Lindl., P.persica(L.) Batsch. And P.salicina Lindl.var.cordata J.Y.Zhang Et Al.

Longyan mume (Prunus mume Sieb et Zucc. ' longyan mei' ) , American plum(P.salicina LindL), Taiwan sweet peach (P. persica (L. )Batsch. ) and Nai (P.salicina Lindl.var.cordata J.Y.Zhang et al. ) belong to Prunus, Rosaceae. Their fruit are used in every time , not only are they eaten raw but also they are processed to dried fruit , fruit jam and fruit confection, etc. All of them have a problem that their fruit are so easier softened than other fruit that they couldn' t be stored and processed , after they are picked. In this study Polygalacturonase inhibiting protein(PGIP) gene which can resist softening and control diseases and insect pests can be cloned from these four fruit tree and its plant recombinant expression vectors can be constructed for breeding new varieties which can resist diseases and insect pests and have good keeping quality.Two specific primers (A primers and B primers)were designed according to the sequences of PGIP genes of Prunus mahaleb L and Phaseolus vulagaris L. .With genomic DNA and cDNA extracted from Longyan mume, American plum, Taiwan sweet peach and Nai PGIP DNA and PGIP cDNA sequences were amplified by polymerase chain reaction (PCR).1) Some fragments used genomic DNA were 1192bp which were cloned by A primers , other fragments were 887bp expect Taiwan sweet peach was 953bp which were amplified by B primers.2)Some fragments used cDNA were 1045bp which were obtained by A primers ,.other were 806bp which used B primers.Blast showed that these Nucleotide sequences have high identities with that of PGIP cloned from Prunus mahaleb L , Prunus armeniaca, malus domestica , pyrus pyrifolia and pyrus communis, etc. The identities were 70%-99%.After these Nucleotide sequences were tranlated into Protein sequence, it is found that some sequences which obtained by RT-PCR used A primers had complete open reading frame (ORF), the ORF was comprised by 990bp of deoxynucleotide encoding 330 amino acid.The result showed that all PGIP DNA sequence had two exons and one intron by comparing PGIP DNA sequence and PGIP cDNA sequence and analyzing ORF. All introns abided the rule of "GT~AG" .