Water deficit triggers phospholipase D activity in the resurrection plant Craterostigma plantagineum.
Phospholipids play an important role in many signaling pathways in animal cells. Signaling cascades are triggered by the activation of phospholipid cleaving enzymes such as phospholipases C, D (PLD), and A(2). Their activities result in the formation of second messengers and amplification of the initial signal. In this study, we provide experimental evidence that PLD is involved in the early events of dehydration in the resurrection plant Craterostigma plantagineum. The enzymatic activity of the PLD protein was activated within minutes after the onset of dehydration, and although it was not inducible by abscisic acid, PLD activity did increase in response to mastoparan, which suggests a role for heterotrimeric G proteins in PLD regulation. Two cDNA clones encoding PLDs, CpPLD-1 and CpPLD-2, were isolated. The CpPLD-1 transcript was constitutively expressed, whereas CpPLD-2 was induced by dehydration and abscisic acid. Immunological studies revealed changes in the subcellular localization of the PLD protein in response to dehydration. Taken together, the data on enzymatic activity as well as transcript and protein distributions allowed us to propose a role for PLD in the events leading to desiccation tolerance in C. plantagineum.
Frank
W
W
Department of Molecular Biotechnology, Fraunhofer Institut für Umweltchemie und Okotoxikologie, Auf dem Aberg 1, D-57392 Schmallenberg, Germany.
Munnik
T
T
Kerkmann
K
K
Salamini
F
F
Bartels
D
D
D000040:Abscisic Acid / Q000494:pharmacology; D000595:Amino Acid Sequence; D001483:Base Sequence; D017931:DNA Primers / Q000235:genetics; D018076:DNA, Complementary / Q000235:genetics / Q000302:isolation & purification; D018744:DNA, Plant / Q000235:genetics / Q000302:isolation & purification; D004789:Enzyme Activation; D015870:Gene Expression; D017343:Genes, Plant; D020962:Heterotrimeric GTP-Binding Proteins / Q000378:metabolism; D036341:Intercellular Signaling Peptides and Proteins; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism; D019684:Magnoliopsida / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D010455:Peptides; D010739:Phospholipase D / Q000235:genetics / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction; D014862:Wasp Venoms / Q000494:pharmacology; D014867:Water / Q000378:metabolism
D017931:DNA Primers; D018076:DNA, Complementary; D018744:DNA, Plant; D036341:Intercellular Signaling Peptides and Proteins; D007527:Isoenzymes; D010455:Peptides; D014862:Wasp Venoms; D014867:Water; C037500:mastoparan; D000040:Abscisic Acid; D010739:Phospholipase D; D020962:Heterotrimeric GTP-Binding Proteins