A calcium-dependent protein kinase is systemically induced upon wounding in tomato plants.
A full-length cDNA clone (LeCDPK1) from tomato (Lycopersicon esculentum) encoding a calcium-dependent protein kinase (CDPK) was isolated by screening a cDNA library from tomato cell cultures exposed to Cladosporium fulvum elicitor preparations. The predicted amino acid sequence of the cDNA reveals a high degree of similarity with other members of the CDPK family. LeCDPK1 has a putative N-terminal myristoylation sequence and presents a possible palmitoylation site. The in vitro translated protein conserves the biochemical properties of a member of the CDPK family. In addition, CDPK activity was detected in soluble and particulate extracts of tomato leaves. Basal levels of LeCDPK1 mRNA were detected by northern-blot analysis in roots, stems, leaves, and flowers of tomato plants. The expression of LeCDPK1 was rapidly and transiently enhanced in detached tomato leaves treated with pathogen elicitors and H2O2. Moreover, when tomato greenhouse plants were subjected to mechanical wounding, a transient increase of LeCDPK1 steady-state mRNA levels was detected locally at the site of the injury and systemically in distant non-wounded leaves. The increase observed in LeCDPK1 mRNA upon wounding correlates with an increase in the amount and in the activity of a soluble CDPK detected in extracts of tomato leaves, suggesting that this kinase is part of physiological plant defense mechanisms against biotic or abiotic attacks.
Chico
José Manuel
JM
Instituto de Investigaciones en Ingeniería Genética y Biología Molecular, Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad de Buenos Aires, Vuelta de Obligado 2490 2(do) piso, 1428 Buenos Aires, Argentina.
Raíces
Marcela
M
Téllez-Iñón
María Teresa
MT
Ulloa
Rita María
RM
D000222:Adaptation, Physiological; D000595:Amino Acid Sequence; D015152:Blotting, Northern; D015139:Blotting, Southern; D015153:Blotting, Western; D002135:Calcium-Binding Proteins / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D003001:Cloning, Molecular; D020231:Colletotrichum / Q000254:growth & development; D015971:Gene Expression Regulation, Enzymologic; D007113:Immunity, Innate / Q000235:genetics; D018551:Solanum lycopersicum / Q000201:enzymology / Q000235:genetics*; D008969:Molecular Sequence Data; D010935:Plant Diseases / Q000382:microbiology; D018515:Plant Leaves / Q000201:enzymology / Q000235:genetics; D011494:Protein Kinases / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction
D002135:Calcium-Binding Proteins; D012333:RNA, Messenger; D011494:Protein Kinases