Molecular cloning and expression analysis of BoRAN3 in Brassica oleracea

Abstract

ABSTRACT According to structural and functional similarities, small GTP-binding proteins can be divided into five distinct families, in which, Ras-related nuclear protein (Ran) GTPases regulates proteins and RNA across nuclear envelope. To excavate differentially expressed proteins in the pistil after pollination, proteomics was recruited. One protein spot was identified as BoRAN3, was down-regulated expressed in the pistil. Phylogenetic tree assay found RAN3 in Brassica oleracea, Eutrema salsugineum, Brassica napus and Brassica rapa grouped into one clade. Compared BoRAN3 expression levels in reproductive organs found it was expressed in all five organs, specifically highly in the pistil. qRT-PCR assays found that BoRAN3 was up-regulated expsed in the early pollination process. Sub-cellular assay demonstrated that BoRAN3 located in the nucleus. GUS assay found that BoRAN3 was expressed in the cotyledon, root, stoma, lateral root primordia, petal, filigree and both the front and the bottom of pistil. Taken together, our results demonstrated that BoRAN3 was highly expressed in the pistil and up-regulated expressed in the pistil during early pollination process. Based on those results, we speculated that the up-regulated expressed of BoRAN3 in the pistil during early pollination process hints that it may related to pollen germination and pollen tube development.