Sequence variability and expression characteristics of the ginseng (Panax ginseng C.A. Meyer) dehydrin gene family

Abstract

The dehydrins (DHN) are a family of late embryo abundant (LEA D-11) proteins, which accumulate during the late stage of seed development or under low temperature or water deficient conditions. They are believed to play a protective role in freezing and drought tolerance. The dehydrin genes exist as multi-gene families. Here, we have identified 9 unique dehydrin genes from Korean ginseng (Panax ginseng C.A. Meyer), a typical medicinal plant. Among these, PgDhn1 and PgDhn2 encode for YSK3- and KS-type dehydrins, respectively, and are very abundant. Gene expression analyses revealed that the majority of the PgDhn gene transcripts are detected under cold, as well as dehydration conditions. The exceptions are PgDhn5 and PgDhn9 - the former being unresponsive to cold treatment, and the latter exhibiting only seed-specific expression. We also identified an alternative transcript of the PgDhn2 gene that harbors an intron in its 3′-untranslated region. Our results may prove useful in further studies of Dhn genes, including investigations into the mechanisms underlying gene expression, the nature of their variations, and their physiological functions.