Characterization of a Pectin Methylesterase Gene Homolog, CaPME1, Expressed in Anther Tissues of Capsicum annuum L.

摘要

A pectin methylesterase gene homolog, designated CaPME1, was identified by RNA-sequencing in the genic male sterile–fertile line 114AB of Capsicum annuum L. The full-length transcript of CaPME1 was 1,747 bp, including a complete coding sequence of 1,662 bp (GenBank accession number: JN246474). The derived protein CaPME1 shares high similarity to members of pectin methylesterase protein family, containing a conserved domain of PMEI at the N terminus and a domain of PME at C-terminal end. The expression of CaPME1 was detected only in flower buds at stage 8 and open flowers of male fertile line, with no detection in any examined organ of male sterility line. The fine expression analysis revealed that CaPME1 expressed specifically in anthers of male fertile line, and there was no expression detected in any other examined organ such as sepals, petals, pistils, roots, stems, or leaves. The putative function of CaPME1 involved in pollen development was also discussed in the present paper. These results suggested that CaPME1 was an anther-specific gene and might be essential for pollen maturation and germination in C. annuum.