A novel calcium-binding protein is expressed in Brassica pistils and anthers late in flower development.

摘要: We describe the cloning and characterization of PCP, a novel calcium-binding protein that is expressed predominantly in pistils anthers Brassica flowers late flower development. A PCP cDNA – isolated from subtracted library enriched transcripts present pistil development potentially encodes 175 amino acid with calculated molecular weight 19.1 kDa. Other than limited homology to repetitive C-terminal polyacidic region none sequences GenBank database shares identity PCP. This unique was purified an Escherichia coli expression system shown bind calcium specific manner, both blot assay by equilibrium dialysis. binds 29 mol per apparent affinity constant 3.2×102/M, values consistent presence high capacity/low-affinity domain. PCP-specific mRNAs are detected stigma style excised open flowers; much lower levels seen root leaf tissue. Expression steadily increases during peaks at opening. antibody first detects one day prior flowering, higher flowers. low level however, not either or extracts. The pattern possible role for pollen-pistil interactions results also discussed light central maintains pollen tube growth fertilization.