title: Abscisic acid-induced rearrangement of intracellular structures associated with freezing and desiccation stress tolerance in the liverwort Marchantia polymorpha.
abstract: The plant growth regulator abscisic acid (ABA) is known to be involved in triggering responses to various environmental stresses such as freezing and desiccation in angiosperms, but little is known about its role in basal land plants, especially in liverworts, representing the earliest land plant lineage. We show here that survival rate after freezing and desiccation of Marchantia polymorpha gemmalings was increased by pretreatment with ABA in the presence of increasing concentrations of sucrose. ABA treatment increased accumulation of soluble sugars in gemmalings, and sugar accumulation was further increased by addition of sucrose to the culture medium. ABA treatment of gemmalings also induced accumulation of transcripts for proteins with similarity to late embryogenesis abundant (LEA) proteins, which accumulate in association with acquisition of desiccation tolerance in maturing seeds. Observation by light and electron microscopy indicated that the ABA treatment caused fragmentation of vacuoles with increased cytosolic volume, which was more prominent in the presence of a high concentration of external sucrose. ABA treatment also increased the density of chloroplast distribution and remarkably enlarged their volume. These results demonstrate that ABA induces drastic physiological changes in liverwort cells for stress tolerance, accompanied by accumulation of protectants against dehydration and rearrangement and morphological alterations of cellular organelles.
authors.affiliation: Graduate School of Science and Engineering, Saitama University, Shimo-Okubo 255, Sakura-ku, Saitama 338-8570, Japan.
authors.forename: Khaleda
authors.initials: K
authors.lastname: Akter
authors.affiliation: Graduate School of Science and Engineering, Saitama University, Shimo-Okubo 255, Sakura-ku, Saitama 338-8570, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Kato
authors.affiliation: Graduate School of Science and Engineering, Saitama University, Shimo-Okubo 255, Sakura-ku, Saitama 338-8570, Japan.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Sato
authors.affiliation: Graduate School of Science and Engineering, Saitama University, Shimo-Okubo 255, Sakura-ku, Saitama 338-8570, Japan; Institute for Environmental Science and Technology, Saitama University, Shimo-Okubo 255, Sakura-ku, Saitama 338-8570, Japan.
authors.forename: Yasuko
authors.initials: Y
authors.lastname: Kaneko
authors.affiliation: Graduate School of Science and Engineering, Saitama University, Shimo-Okubo 255, Sakura-ku, Saitama 338-8570, Japan; Institute for Environmental Science and Technology, Saitama University, Shimo-Okubo 255, Sakura-ku, Saitama 338-8570, Japan. Electronic address: takezawa@mail.saitama-u.ac.jp.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Takezawa
mesh_terms: D000040:Abscisic Acid / Q000494:pharmacology*; D002736:Chloroplasts / Q000378:metabolism; D003890:Desiccation; D005615:Freezing; D018506:Gene Expression Regulation, Plant / Q000187:drug effects*; D047008:Marchantia / Q000187:drug effects* / Q000235:genetics / Q000502:physiology / Q000648:ultrastructure; D008854:Microscopy, Electron; D010455:Peptides / Q000378:metabolism*; D010937:Plant Growth Regulators / Q000494:pharmacology*; D010940:Plant Proteins / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics; D018749:RNA, Plant / Q000235:genetics; D013312:Stress, Physiological; D013395:Sucrose / Q000378:metabolism / Q000494:pharmacology
chemical_list: D010455:Peptides; D010937:Plant Growth Regulators; D010940:Plant Proteins; D012333:RNA, Messenger; D018749:RNA, Plant; C066246:late embryogenesis abundant protein, plant; D013395:Sucrose; D000040:Abscisic Acid
keywords: Abscisic acid; Desiccation; Freezing; Liverwort; Ultrastructure