Molecular Cloning, Sequence Analysis, and Expression of the Polygalacturonase-inhibiting Protein (PGIP) Gene in Mulberry

摘要

A full-length cDNA sequence encoding polygalacturonase-inhibiting protein (PGIP) from mulberry, which we designated MPGIP (GenBank accession no.: HM044383), was cloned based on mulberry expressed sequence tags (ESTs). Sequence analysis showed that the MPGIP is 1,274 base pairs (bp) in length, encoding 333 amino acids with a predicted molecular weight of 37.29 kDa and an isoelectric point of 7.25. The expression levels of MPGIP at different developmental stages in mulberry leaves and flowers and in different tissues were investigated. The results showed that MPGIP transcripts were most abundantly expressed in the young leaf, and the expression level of the mRNA could be increased significantly under salicylic acid (SA), abscissic acid (ABA), and NaCl stress conditions compared to the normal growth environment. And we also expressed the recombinant protein. This is to help understand a molecular basis for signal transduction mechanism underlying the stress response in mulberry.