抄録
Bryophytes such as mosses and liverworts generally possess a high degree of dehydration stress tolerance allowing them to survive long-term desiccation and freezing without causing significant damages. Abscisic acid (ABA), known to be involved in regulation of seed maturation and stomata closure in higher plants, has been postulated to play a key role in development of the dehydration stress tolerance of bryophytes. In the moss Physcomitrella patens, the presence of conserved cellular mechanisms of ABA-induced signaling and gene expression for the stress tolerance have been suggested. In contrast, very little is known about the mechanisms underlying ABA responses in liverworts. Our physiological analyses using the liverwort Marchantia polymorpha showed the role of ABA in dormancy and sugar metabolism. Recent molecular approaches have revealed the presence of conserved mechanisms for ABA signaling leading to gene expression and stress tolerance in liverworts.