The transcriptome analysis of MpPYL1 null mutant and MpPYL1 overexpressing plant in Marchantia polymorpha

Abscisic acid (ABA) is a phytohormone mediating developmental and physiological processes in vegetative as well as reproductive organs in plants. ABA elicits plant responses through binding to intracellular receptors known as PYR/PYL/RCARs. ABA functions as a phytohormone have been shown not only in angiosperms but also in non-vascular basal land plants like mosses. The role of ABA in stress signaling has been also suggested in liverworts, consisting of another class of basal land plants. Rise in endogenous ABA is associated with development of desiccation tolerance in thalli of liverworts Exormotheca holstii and Riccia fluitans. We previously showed that gemma, a dormant form for asexual reproduction in the liverwort Marchantia polymorpha, shows a sensitive response to ABA. ABA induces accumulation of LEA-like transcripts and soluble sugars, mainly sucrose, in M. polymorpha with enhancement of tolerance to desiccation. Exogenously applied sucrose with ABA inhibited growth of gemmae and further enhanced the desiccation tolerance, thus, it was thought that sucrose affects the ABA signaling pathway and accelerated accumulation of LEA-like transcripts and further accumulation of sucrose. To understand mechanisms underlying ABA responses in liverworts, a search of genes for the PYR/PYL/RCAR-like receptor in M. polymorpha was conducted. The gene designated M. polymorpha PYR/PYL/RCAR-like1 (MpPYL1) analyzed by transient gene expression assays and in transgenic liverworts to determine its role in ABA response, abiotic stress and sugar signaling.