Pleiotropic effect of chromosome 5A and the mvp mutation on the metabolite profile during cold acclimation and the vegetative/generative transition in wheat.

backgroundWheat is the leading source of vegetable protein in the human diet, and metabolites are crucial for both plant development and human nutrition. The recent advances in metabolomics provided an opportunity to perform an untargeted metabolite analysis in this important crop.

resultsWheat was characterised at the metabolite level during cold acclimation and transition from the vegetative to the generative phase. The relationship between these changes and chromosome 5A and the maintained vegetative phase (mvp) mutation was also investigated. Samples were taken from the shoots and crowns during four developmental stages: plants grown at 20/17°C, after cold treatment but still during the vegetative phase, at the double ridge and during spikelet formation. The levels of 47 compounds were identified by gas chromatography-mass spectrometry, of which 38 were annotated. The cold treatment, in general, increased the concentrations of osmolites but not in all lines and not equally in the shoots and crowns. The accumulation of proline was not associated with the vernalisation process or with frost tolerance. The mvp mutation and chromosome 5A substitutions altered the amounts of several metabolites compared to those of the Tm and CS, respectively, during each developmental stage. The Ch5A substitution resulted in more substantial changes at the metabolite level than did the Tsp5A substitution. While Ch5A mainly influenced the sugar concentrations, Tsp5A altered the level of tricarboxylic acid cycle intermediates during the vegetative/generative transition. A much higher trehalose, proline, glutamine, asparagine, and unidentified m/z 186 content was detected in crowns than in shoots that may contribute to the frost tolerance of crowns.

conclusionsSubstantial influences of chromosome 5A and the mvp mutation on metabolism during four different developmental stages were demonstrated. The distinct and overlapping accumulation patterns of metabolites suggest the complex genetic regulation of metabolism in the shoots and crowns.