The Arabidopsis PLAT domain protein1 is critically involved in abiotic stress tolerance.
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.
Institute of Plant Sciences, University of Graz, Graz, Austria; Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju, Korea.
Tae Kyung
TK
Hyun
Institute of Plant Sciences, University of Graz, Graz, Austria; Department of Plant and Environmental Sciences, Copenhagen Plant Science Centre, University of Copenhagen, Taastrup, Denmark.
Eric
E
van der Graaff
Institute of Plant Sciences, University of Graz, Graz, Austria; Departamento de Nutrición Vegetal, CEBAS-CSIC, Campus Espinardo, Murcia, Spain.
Alfonso
A
Albacete
Institute of Plant Sciences, University of Graz, Graz, Austria; Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju, Korea.
Seung Hee
SH
Eom
Institute of Plant Sciences, University of Graz, Graz, Austria; Department of Plant and Environmental Sciences, Copenhagen Plant Science Centre, University of Copenhagen, Taastrup, Denmark.
Dominik K
DK
Großkinsky
Institute of Plant Sciences, University of Graz, Graz, Austria.
Hannah
H
Böhm
Institute of Plant Sciences, University of Graz, Graz, Austria.
Ursula
U
Janschek
Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju, Korea.
Yeonggil
Y
Rim
Department of Pharmaceutical Biology, University of Würzburg, Würzburg, Germany.
Walid Wahid
WW
Ali
Department of Molecular Biotechnology and Kumho Life Science Laboratory, College of Agriculture and Life Sciences, Chonnam National University, Gwangju, Korea.
Soo Young
SY
Kim
Institute of Plant Sciences, University of Graz, Graz, Austria; Department of Plant and Environmental Sciences, Copenhagen Plant Science Centre, University of Copenhagen, Taastrup, Denmark; Global Change Research Centre, CzechGlobe AS CR, v.v.i., Drásov, Czech Republic.
Thomas
T
Roitsch
D000040:Abscisic Acid / Q000494:pharmacology; D017360:Arabidopsis / Q000145:classification / Q000254:growth & development / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D050976:Basic-Leucine Zipper Transcription Factors / Q000235:genetics / Q000378:metabolism; D003080:Cold Temperature; D055864:Droughts; D024202:Electrophoretic Mobility Shift Assay; D059865:Endoplasmic Reticulum Stress / Q000187:drug effects; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D010802:Phylogeny; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D012492:Salts / Q000737:chemistry / Q000494:pharmacology; D015398:Signal Transduction / Q000187:drug effects; D013312:Stress, Physiological; D015533:Transcriptional Activation; D014415:Tunicamycin / Q000633:toxicity
D029681:Arabidopsis Proteins; D050976:Basic-Leucine Zipper Transcription Factors; D012492:Salts; D014415:Tunicamycin; D000040:Abscisic Acid