192-10 Nitrogen Stress Induced Modification of the Foliar Phytochemical Composition in Strawberries.
In general, across both cultivars, the content of primary and secondary metabolites exhibited a contrasting trend with respect to N treatments, where the content of primary metabolites increased with N-sufficiency, whereas the content of secondary metabolites increased with N-deficiency. Non-targeted metabolomics putatively identified more than forty phenylpropanoids encompassing hydroxycinnmate derivatives, flavones, flavonols and flavan-3-ols. Both the total and extractable proanthocyanidins content decreased with increase in N fertilization, which then remained unchanged beyond 44 mg N, exhibiting a non-linear relationship of phytochemical content with N-treatments. In contrast, ellagitannins, encompassing castalgin and geraniin, initially decreased with increasing N, but increased at highest rate of N fertilization. Flavone content decrease from 12 to 44 mg N, but increased at 81mg N; however, flavonols did not show the increase at higher N-level, elucidating potential role of difference in the hydroxylation as a mode to mitigate N stress. In general, plants receiving lower N rates exhibited highest antioxidant capacity.