Abstract
In higher plants, developing seeds are dehydrated in the maturation phase, and subsequently rehydrated during germination. Since aquaporins facilitate the osmotic water transport across biomembranes, they might have some physiological roles during embryo development. In order to reveal physiological roles of plant aquaporins during embryogenesis, we analyzed DcTIP1 encoding a tonoplast intrinsic protein (TIP) in carrot (Daucus carota) somatic embryogenesis. The higher expression of DcTIP1 was detected in somatic embryos and dry seeds. By contrast, the lower expression was detected in seedlings, leaves, petioles, and roots. The expression of DcTIP1 in somatic embryos was significantly increased in response to exogenous abscisic acid (ABA) treatment. Moreover, the upstream region of DcTIP1 included the regions similar to C-ABI3 and DcECP40 promoters. Our results indicate that DcTIP1 expression is abundant in embryos and ABA-inducible, and suggest DcTIP1 might be involved in ABA-inducible desiccation tolerance in carrot somatic and zygotic embryos.
