TY - JOUR A1 - Hyun, Tae Kyung A1 - van der Graaff, Eric A1 - Albacete, Alfonso A1 - Eom, Seung Hee A1 - Grosskinsky, Dominik K. A1 - Böhm, Hannah A1 - Janschek, Ursula A1 - Rim, Yeonggil A1 - Ali, Walid Wahid A1 - Kim, Soo Young A1 - Roitsch, Thomas T1 - The Arabidopsis PLAT Domain Protein1 is Critically Involved in Abiotic Stress Tolerance JF - PLOS ONE N2 - Despite the completion of the Arabidopsis genome sequence, for only a relatively low percentage of the encoded proteins experimental evidence concerning their function is available. Plant proteins that harbour a single PLAT (Polycystin, Lipoxygenase, Alpha-toxin and Triacylglycerol lipase) domain and belong to the PLAT-plant-stress protein family are ubiquitously present in monocot and dicots. However, the function of PLAT-plant-stress proteins is still poorly understood. Therefore, we have assessed the function of the uncharacterised Arabidopsis PLAT-plant-stress family members through a combination of functional genetic and physiological approaches. PLAT1 overexpression conferred increased abiotic stress tolerance, including cold, drought and salt stress, while loss-of-function resulted in opposite effects on abiotic stress tolerance. Strikingly, PLAT1 promoted growth under non-stressed conditions. Abiotic stress treatments induced PLAT1 expression and caused expansion of its expression domain. The ABF/ABRE transcription factors, which are positive mediators of abscisic acid signalling, activate PLAT1 promoter activity in transactivation assays and directly bind to the ABRE elements located in this promoter in electrophoretic mobility shift assays. This suggests that PLAT1 represents a novel downstream target of the abscisic acid signalling pathway. Thus, we showed that PLAT1 critically functions as positive regulator of abiotic stress tolerance, but also is involved in regulating plant growth, and thereby assigned a function to this previously uncharacterised PLAT domain protein. The functional data obtained for PLAT1 support that PLAT-plant-stress proteins in general could be promising targets for improving abiotic stress tolerance without yield penalty. KW - salicylic acid KW - gene expression KW - signal transduction KW - cold stress KW - salt stress KW - abscisic acid KW - endoplasmatic reticulum KW - transcription factors KW - pseudomonas syringae KW - plants response Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-114648 VL - 9 IS - 11 ER -