The objective of the present work was to determine what impact extremely high nitrogen dosages would have on proline metabolism in order to use this amino acid as a bioindicator of N status of green bean plants (Phaseolus vulgaris L. cv. Strike). In this effort, we identified the most favourable pathway of proline synthesis under our experimental conditions. The N was applied to the nutrient so...

Petunias (Petunia hybrida cv. 'Mitchell') accumulate free proline (Pro) under drought-stress conditions. It is therefore believed that Pro acts as an osmoprotectant in plants subjected to drought conditions. Petunia plants were transformed by Delta(1)-pyrroline-5-carboxylate synthetase genes (AtP5CS from Arabidopsis thaliana L. or OsP5CS from Oryza sativa L.). The transgenic plants accumulated ...

An interesting observation, reported for transgenic plants that have been engineered to overproduce osmolytes, is that they often exhibit impaired growth in the absence of stress. As growth reduction and accumulation of osmolytes both typically result from adaptation, we hypothesized that growth reduction may actually result from osmolyte accumulation. To examine this possibility more closely, ...

Dehydration responsive element binding proteins (DREB) are members of a larger family of transcription factors, many of which have been reported to contribute to plant responses to abiotic stresses in several species. While, little is known about their role in potato (Solanum tuberosum). This report describes the cloning and characterization of a DREB transcription factor cDNA, StDREB2, isolate...

It has been established that drought-responsive element binding (DREB) proteins correspond to transcription factors which play important regulatory roles in plant response to abiotic and biotic stresses. In this study, a novel cDNA encoding DREB transcription factor, designated StDREB1, was isolated from potato (Solanum tuberosum L.). This protein was classified in the A-4 group of DREB subfami...

Ethylene responsive factors (ERFs) play important roles in the abiotic stress; however, only a few ERF genes from woody plants have been functionally characterized. In the present study, an ERF gene from Betula platyphylla (birch), BpERF11, was functionally characterized in response to abiotic stress. BpERF11 is a nuclear protein, which could specifically bind to GCC boxes and DRE motifs. BpERF...

Previously, we identified >1,500 genes that were induced by high salt stress in sheepgrass (Leymus chinensis, Gramineae: Triticeae) when comparing the changes in their transcription levels in response to high salt stress by next-generation sequencing. Among the identified genes, a gene of unknown function (designated as Leymus chinensis salt-induced 1, LcSAIN1) showed a high sequence identity t...

We further investigated the role of the Arabidopsis CBF regulatory genes in cold acclimation, the process whereby certain plants increase in freezing tolerance upon exposure to low temperature. The CBF genes, which are rapidly induced in response to low temperature, encode transcriptional activators that control the expression of genes containing the C-repeat/dehydration responsive element DNA ...

The objective of the present work was to determine the impact of nitrogen deficiency on proline metabolism in French Bean plants (Phaseolus vulgaris L. cv. Strike). The nitrogen was applied to the nutrient solution in the form of NH4NO3 at 1.45 mM (N1), 2.90 mM (N2) and 5.80 mM (N3, optimal level). Our results indicate N deficiency is characterised by a decline in proline accumulation both in t...

The modulation of primary nitrogen metabolism by water deficit through ABA-dependent and ABA-independent pathways was investigated in the model legume Medicago truncatula. Growth and glutamate metabolism were followed in young seedlings growing for short periods in darkness and submitted to a moderate water deficit (simulated by polyethylene glycol; PEG) or treated with ABA. Water deficit induc...