title: Characterization of upregulated genes associated with high phosphorus accumulation in cucumber.
abstract: Excessive application of phosphorus (P)-rich manures to agricultural lands often results in P-accumulation in soils leading to water pollution through runoffs and leaching. Use of suitable plant species that can extract and sequester excess P from soil into their biomass is an effective method of remediation of P-contaminated soils. Knowledge on the molecular responses of plants to high P-accumulation and tolerance is lacking. Therefore, a suppression subtractive hybridization (SSH) strategy was employed to identify and elucidate the pattern of gene expression related to P-tolerance and accumulation in cucumber (Cucumis sativus L.), a P-accumulator plant. RNA isolated from cucumber grown in high P was used for 'tester' cDNA synthesis and SSH library preparation. A total of 63 cDNAs were identified as showing upregulated expression in this plant in response to high P. No putative function could be assigned to 7 (11%) of the 63 upregulated high P-modulated genes and 11 expressed sequence tags (ESTs) (17%) did not match database entries. The remaining 45 ESTs were grouped into five functional classes. The majority of these ESTs belonged to three groups: 'metabolism', 'protein synthesis/degradation and signaling' and 'cell structure/cell wall'. Only six 'stress/defense'-related ESTs were identified from this library. The results of reverse northern blot analysis was further confirmed and validated through semi-quantitative RT-PCR carried out with representative ESTs identified in this study. The research reported here may contribute to a preliminary understanding of the high P-related gene expression in this P-accumulating plant.
authors: Department of Biology, Western Kentucky University, Bowling Green, KY 42101, USA.
authors: Priya
authors: P
authors: Padmanabhan
authors: Perumal
authors: P
authors: Venkatachalam
authors: Shivendra V
authors: SV
authors: Sahi
mesh_terms: D000222:Adaptation, Physiological; D018553:Cucumis sativus / Q000235:genetics* / Q000378:metabolism; D018076:DNA, Complementary / Q000235:genetics; D020224:Expressed Sequence Tags; D018506:Gene Expression Regulation, Plant; D015723:Gene Library; D017343:Genes, Plant; D010758:Phosphorus / Q000378:metabolism*; D018749:RNA, Plant / Q000235:genetics; D017422:Sequence Analysis, DNA
chemical_list: D018076:DNA, Complementary; D018749:RNA, Plant; D010758:Phosphorus