Effect of Imbibition Temperature on Gene Expression in Arabidopsis Seeds

Abstract

Temperature is a primary factor for seed germination.To classify genes expressed in imbibed Arabidoopsis seeds and to find genes related to germination inhibition at high temperature, we adopted 22k Arabidopsis2 oligo-microarray from Agilent. We picked 9,138 genes that showed significant signal change more than 2 fold by imbibition. We found that the number of genes and the degree of change increased with imbibition time at 22^oC, and the number and the change were relatively small at 34^oC. The patterns of gene expression were clustered into 4 groups; 6h at 22^oC, 6h at 34^oC, more than 12h at 22^oC and more than 12h at 34^oC. There was no visible germination by 24h at 22^oC, and rupture of seed coat was observed after 36h. These results suggest that temperature determined the pattern of gene expression until 6h, and induced the gene expression related to germination induction or inhibition after 12h.