Cloning and characterization of a salt stress-inducible small GTPase gene from the model grass species Lolium temulentum

• Published in: Journal of plant physiology Vol. 165; no. 6; pp. 651 - 661
• Main Authors: Dombrowski, James E., Baldwin, James C., Martin, Ruth C.
• Format: Journal Article
• Language: English
• Published: Jena Elsevier GmbH 01.01.2008; Elsevier
• Subjects: abiotic stress; Amino Acid Sequence; amino acid sequences; Base Sequence; Biological and medical sciences; Cloning, Molecular; COR413; Dehydration stress; Enzymes; Fundamental and applied biological sciences. Psychology; G-proteins; Gene Expression Profiling; Gene Expression Regulation, Plant - drug effects; GTPase; guanosinetriphosphatase; Lolium - drug effects; Lolium - enzymology; Lolium - genetics; Lolium temulentum; Metabolism; Models, Biological; molecular cloning; Molecular Sequence Data; Monomeric GTP-Binding Proteins - chemistry; Monomeric GTP-Binding Proteins - genetics; nucleotide sequences; Phylogeny; Plant physiology and development; plant proteins; plant response; RNA, Messenger - genetics; RNA, Messenger - metabolism; RNA, Plant - genetics; RNA, Plant - metabolism; Salt stress; seed development; Seeds - drug effects; Seeds - embryology; Seeds - enzymology; Seeds - genetics; sequence analysis; Sequence Analysis, DNA; Sodium Chloride - pharmacology; Stress, Physiological - drug effects; suppression subtractive hybridization; ABA; UV; GTP; ORF; Salt stress; SDS; COR413; SSH; Dehydration stress; smGTP; GDP; PEG; RACE; Lolium temulentum; NaCl; GTPase; PCR; Monocotyledones; Gene; Gramineae; Angiospermae; Spermatophyta; Stress; Salinity
• ISSN: 0176-1617; 1618-1328
• DOI: 10.1016/j.jplph.2007.06.003

A gene encoding a small guanosine triphosphate (GTP)-binding protein ( smGTP) related to the Rab2 gene family of GTPases was identified during the analysis of a salt stress suppression subtractive hybridization (SSH) expression library from the model grass species Lolium temulentum L. (Darnel ryegrass). The smGTP gene was found to have a low-level constitutive expression and was strongly induced by salt stress in root, crown and leaf tissues. The expression pattern of the smGTP gene was compared against two additional stress genes identified in the SSH expression library, the well-characterized dehydration stress tolerance gene, delta 1-pyrroline-5-carboxylate synthetase ( P5CS) encoding for a key enzyme in proline biosynthesis, and the cold response gene COR413. The genes were analyzed for their response to salinity as well as their responses to 7 different forms of abiotic stress in L. temulentum plants. The smGTP gene displayed an expression pattern similar to the P5CS gene, suggesting a role in dehydration stress. In contrast, the COR413 gene was found to be up-regulated in response to all stresses tested and has utility as a general stress marker in grass plants.