Some Genes in a NAC Transcription Factor Family Play Cooperated Roles in the Developmental Process of Rice Plant

Information of the co-expressing genes analysis with the focused gene sometimes gives us valuable hints for the elucidation of the gene network system. We have analyzed the data of coexpressed genes using the RICE FREND database (http://ricefrend.dna.affrc.go.jp/single-guide-gene.html). We have focused to the gene expression data of about 130 genes encoding NAC transcription factors. NAC transcription factor is known to the plant specific transcription factors and known to contributing to the developmental processes such as leaf formation, flowering etc. and also to the responses to various environmental stresses. By checking the developmental expression pattern of each NAC gene and coexpressing genes to each NAC gene, we have found that

1) Some stage specific expressing NAC genes such as inflorescence, anther, ovary and endosperm, and embryo are identified.

2) By comparing the members of coexpressing genes with the NAC genes, many of the coexpressing genes are commonly appeared with the members of NAC genes.

3) By comparing the members of coexpressing genes, it is possible to discriminate the contribution of the NAC genes to the different gene network systems.

Common appearance of the coexpressing genes among the gene family members are not only observed in the NAC gene family, but many other gene families tested. This observation suggests that increase of the gene family members suggest not only the gain of the different functions but also conversion to the same gene functions.