Physiological roles of ERD10 in abiotic stresses and seed germination of Arabidopsis.

While screening for genes affected by cold, we found that Early Responsive to Dehydration 10 (ERD10)was induced by cold treatment. To further investigate the physiological functions of ERD10, we analyzed the T-DNA insertion mutant of ERD10 as well as the expression of ERD10 in response to various stress conditions. The erd10 mutant showed reduced stress tolerance relative to wild-type plants. Activation of the CBF/DREB1 genes by cold stress did not occur in the erd10 mutant, indicating that an increased level of ERD10 is required to subsequently activate the CBF/DREB1 genes and their downstream target genes during treatment with cold stress in Arabidopsis. In addition, we showed that accumulation of the ERD10 transcript in developing seeds was necessary for completion of seed development. Erd10 mutant seeds were abnormally shaped and showed reduced germination. These results suggest that ERD10 can play roles both in protection of the plants from various stresses, including cold and dehydration, and also in seed development and germination.