Metabolic profile of canola (Brassica napus L.) seedlings under hydric, osmotic and temperature stresses

Canola is an important oilseed crop and its oil is used in human diet and biodiesel production. Abiotic stressors severely constrain canola growing causing economic losses. Under adverse conditions, plant cells coordinate their metabolic pathways to produce anti-stress agents. The understanding of the metabolic profile can be used to improve target traits since there is a direct relationship with the phenotype. Here we take advantage of the nontargeted metabolite profiling analysis GC-MS technique to assess the differences in metabolite accumulation in canola seedling tissues subjected to heat, waterlogging, drought and salt stresses. Phenotypically, abiotic stresses affected canola root development, mainly in waterlogging, salt and drought conditions, in which root length was increased. We assayed the metabolic profile in each tissue and abiotic stress and organic acids, free amino acid and sugars were detected. Accumulation of these metabolites were variable between shoots and roots under abiotic stresses. Heat stress affected mainly shoots increasing some essential and non-essential amino acids and sucrose while decreasing glucose and fructose contents. Waterlogging also affected mainly shoots decreasing malic and citric acids, some essential and non-essential amino acids and xylose content. Salt stress leads to a reduction of most of the metabolic compounds from organic acids, free amino acid and sugar groups in shoots and roots. Controversially, drought stress resulted in an increasing in most of the metabolite groups in shoots and roots. Shoots presented greater variation in metabolite content in response to abiotic stress. Our data is useful as basic knowledge to improve canola specific traits.

Automated summary

The accumulation of metabolites in canola seedlings under different abiotic stresses was analyzed. Heat stress mainly affected the shoots, increasing some amino acids and sucrose while decreasing glucose and fructose contents. Waterlogging stress also mainly affected the shoots, decreasing the contents of citric acid, malic acid, some amino acids, and xylose. Salt stress led to a reduction of most metabolites in shoots and roots. Conversely, drought stress resulted in an increase of metabolite groups in both shoots and roots.