Comparative Transcriptome Analysis Between Pre- and Post-Pollination in Arabidposis thaliana

Pollination is an important early step for sexual reproduction in angiosperms. In Arabidopsis thaliana, sequential pollination events, from pollen adhesion on stigma surface to pollen tube germination and elongation, occur on the stigmatic papilla cell, and then pollen tube exactly penetrates into the stigma and finally fertilizes with a female gametophyte. It has been considered that these pollination systems are initiated and regulated by interaction between papilla cell and pollen. Here, we report the characterization of gene expression profiles among non pollinated- (NP), compatible pollinated- (CP) and incompatible pollinated- (IP) papilla cells in A. thaliana. By the cell type-specific transcriptome analysis, from a combination of laser microdissection and RNA sequencing, 15,475, 17,360 and 16,918 genes were identified as the papilla cell expressed genes for NP, CP and IP papilla cells, respectively, and, among them, 14,392 genes were commonly found in all data sets. In differentially expressed genes (DEGs) analysis, 147 and 71 genes were up-regulated in CP and IP papilla cells, and 115 and 46 genes were down-regulated in CP and IP papilla cells. Through Gene Ontology and metabolic pathway analyses, it was revealed that papilla cells are active, as a female reproductive organ in pollination, particularly in information exchange, signal transduction, internal physiological change and external morphological modification. This study provides fundamental knowledge of molecular mechanisms on pollination in papilla cell, leading our understanding of the reproductive role of papilla cells.