Molecular characterization of XVSAP1, a stress-responsive gene from the resurrection plant Xerophyta viscosa Baker.
The strategy of 'complementation by functional sufficiency' was used to isolate a cDNA designated XVSAP1 from a cDNA library constructed from dehydrated Xerophyta viscosa Baker leaves. Analysis of the cDNA sequence indicated a highly hydrophobic protein with six transmembrane regions. Southern blot analysis revealed that there are at least two copies of XVSAP1 in X. viscosa. The deduced amino acid sequence showed 49% identity to WCOR413, a low-temperature-regulated protein from wheat. The protein also showed between 25% to 56% identity to WCOR413-like proteins from Arabidopsis thaliana. Expression of XVSAP1 in Escherichia coli (srl::Tn10) conferred osmotic stress tolerance when the cells were grown in 1 M sorbitol. Analysis of gene expression using semi-quantitative RT-PCR indicated that XVSAP1 is induced by dehydration, salt stress (100 mM), both low (4 degrees C) and high temperature (42 degrees C) and high light treatment (1500 micromol m(-2) s(-1)). These results suggest that XVSAP1 may have a significant role to play in the response of X. viscosa to abiotic stresses.
Garwe
Dahlia
D
Molecular and Cell Biology Department, University of Cape Town, Private Bag, Rondebosch, 7701, South Africa.
Thomson
Jennifer A
JA
Mundree
Sagadevan G
SG
D000595:Amino Acid Sequence; D001483:Base Sequence; D015139:Blotting, Southern; D018076:DNA, Complementary; D018744:DNA, Plant; D004926:Escherichia coli; D017343:Genes, Plant; D019684:Magnoliopsida / Q000235:genetics*; D008969:Molecular Sequence Data; D009997:Osmotic Pressure; D010940:Plant Proteins / Q000235:genetics; D011994:Recombinant Proteins; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid
D018076:DNA, Complementary; D018744:DNA, Plant; D010940:Plant Proteins; D011994:Recombinant Proteins