Gene expression profiling identifies two regulatory genes\ud controlling dormancy and ABA sensitivity in Arabidopsis\ud seeds

摘要

Seed dormancy is a very important trait that maximizes the survival of seed in nature, the control of which can\udhave important repercussions on the yield of many crop species. We have used gene expression profiling to\udidentify genes that are involved in dormancy regulation in Arabidopsis thaliana. RNA was isolated from\udimbibed dormant (D) and after-ripened (AR) ecotype C24 seeds, and then screened by quantitative RT-PCR\ud(qRT-PCR) for differentially expressed transcription factors (TFs) and other regulatory genes. Out of 2207 genes\udscreened, we have identified 39 that were differentially expressed during the first few hours of imbibition. After\udanalyzing T-DNA insertion mutants for 22 of these genes, two displayed altered dormancy compared with the\udwild type. These mutants are affected in genes that encode a RING finger and an HDZip protein. The first,\udnamed DESPIERTO, is involved in ABA sensitivity during seed development, regulates the expression of ABI3,\udand produces a complete loss of dormancy when mutated. The second, the HDZip (ATHB20), is expressed\udduring seed germination in the micropylar