Group A PP2Cs evolved in land plants as key regulators of intrinsic desiccation tolerance

• Published in: Nature communications 2013-07, Vol.4 (1), p.2219, Article 2219
• Main Authors: Komatsu, Kenji, Suzuki, Norihiro, Kuwamura, Mayuri, Nishikawa, Yuri, Nakatani, Mao, Ohtawa, Hitomi, Takezawa, Daisuke, Seki, Motoaki, Tanaka, Maho, Taji, Teruaki, Hayashi, Takahisa, Sakata, Yoichi
• Format: Article
• Language: English
• Subjects: 631/181; 631/449/2661; Abscisic acid; Abscisic Acid - pharmacology; Adaptation, Physiological - drug effects; Adaptation, Physiological - genetics; Bryopsida - enzymology; Bryopsida - genetics; Bryopsida - growth & development; Carbohydrates; Desiccation; Evolution, Molecular; Flowers & plants; Freezing; Gene Dosage - genetics; Gene Expression Profiling; Gene Expression Regulation, Plant - drug effects; Genes; Humanities and Social Sciences; Humidity; Kinases; Models, Biological; multidisciplinary; Mutation - genetics; Phosphatase; Phosphoprotein Phosphatases - metabolism; Plant Development - drug effects; Plant Development - genetics; Plant Proteins - metabolism; Protein Kinases - metabolism; Protein Phosphatase 2C; Proteins; Regulation; Salinity; Science; Science (multidisciplinary); Signal Transduction - drug effects; Signal Transduction - genetics; Solubility; Stress, Physiological - drug effects; Stress, Physiological - genetics
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/ncomms3219

Vegetative desiccation tolerance is common in bryophytes, although this character has been lost in most vascular plants. The moss Physcomitrella patens survives complete desiccation if treated with abscisic acid (ABA). Group A protein phosphatases type 2C (PP2C) are negative regulators of abscisic acid signalling. Here we show that the elimination of Group A PP2C is sufficient to ensure P. patens survival to full desiccation, without ABA treatment, although its growth is severely hindered. Microarray analysis shows that the Group A PP2C-regulated genes exclusively overlap with genes exhibiting a high level of ABA induction. Group A PP2C disruption weakly affects ABA-activated kinase activity, indicating Group A PP2C action downstream of these kinases in the moss. We propose that Group A PP2C emerged in land plants to repress desiccation tolerance mechanisms, possibly facilitating plants propagation on land, whereas ABA releases the intrinsic desiccation tolerance from Group A PP2C regulation. Abscisic acid plays an essential role in the induction of vegetative desiccation tolerance in bryophytes. Here the authors show that elimination of protein phosphatases 2C is sufficient for the moss Physcomitrella patens to survive desiccation without the assistance of abscisic acid.