Identification of ovule specific proteins associated with apomixis and sexuality in Cenchrus ciliaris

Abstract

In order to identify possible specific markers associated with pre and post meiotic stages of megasporogenesis, ovaries representing pre and post-meiotic stages of apomictic and sexual segregants of an F2 mapping population of Cenchrus ciliaris were studied using native and SDS-polyacrylamide gel electrophoresis. Four differentiating proteins of ovaries showed different patterns of associations. While one 97 kDa protein was associated with ovaries at pre-meiotic stage, one 80 kDa protein was absent in ovaries at post-meiotic stage. A 60 kDa protein was observed in pre and post meiotic sexual ovaries and a 50 kDa protein was associated with pre-meiotic ovaries of both sexual and apomictic plants. Dendrogram analysis using protein polymorphism indicated two groups, one with pre-meiotic apomictic and sexual ovaries while the other included post meiotic apomictic and sexual ovaries. Esterase enzyme exhibited maximum polymorphism among four different types of ovaries. Out of 43 putative alleles scored across 15 isozyme loci of six enzymes, six alleles of Est-1 were associated with pre meiotic ovaries of apomictic plants among which 3 were conspicuously absent in sexual plants altogether. Dendrogram based on isozymes indicated two groups, one indicating three stages viz., pre and post-meiotic sexual as well as post meiotic apomictic ovaries while pre-meiotic apomictic ovaries showed a distinct group.