Insights on the Adaptation of Foeniculum vulgare Mill to Iron Deficiency

Iron (Fe) deficiency causes great disturbances to plant growth, productivity and metabolism. This study investigated the effect of bicarbonate-induced Fe deficiency on Foeniculum vulgare (Mill) growth, nutrient uptake, the accumulation of secondary metabolites and the impact on bioactivities. When grown under indirect Fe deficiency conditions (Fe+ (+)Bic), the plants decreased their total mass, an effect that was clearly evident in shoots (-28%). Instead, roots were the main organ affected regarding variations in the phenolic profile and their respective functionalities. Hydromethanolic extracts from bicarbonate-treated roots had a remarkable increase in the levels of phenolic compounds, both of flavonoids (isoquercetin and isorhamnetin) and phenolic acids (gallic acid, chlorogenic acid, syringic acid, ferulic acid, caffeic acid and trans-cinnamic acid), when compared to equivalent extracts from control plants. In addition, they exhibited higher scavenging abilities of DPPH center dot, NO center dot, RO2 center dot, as well as inhibitory capacities towards the activity of lipoxygenase (LOX), xanthine oxidase (XO) and acetylcholinesterase (AChE). The overall results suggest that fennel species may modulate secondary metabolites metabolism to fight damages caused by iron deficiency.

Automated summary

Iron deficiency significantly affects the growth and secondary metabolism of fennel plants, with roots being the most affected organ. Bicarbonate treatment increases the levels of phenolic compounds in roots and enhances their antioxidant capacities. This suggests that fennel species can modulate secondary metabolites metabolism to counteract damages caused by iron deficiency.