How do plants respond biochemically to fire? Biosynthesis of
photosynthetic pigments and secondary metabolites in response to this
disturbance
Abstract
Fire-prone ecosystems and their vegetation have evolved in response to
this disturbance. Stress produced by fires promotes the biosynthesis of
secondary metabolites which could alter subsequent fire regimes. The aim
of this work was to evaluate the variation in the biosynthesis of
chlorophylls, carotenoids, phenolic compounds and tannins in response to
fire. Leaves of six native species were selected and three experimental
burns (EB) were conducted. Spectrophotometric methods were used to
quantify the metabolites. As results, a temporary variation on the
biosynthesis of chlorophylls and secondary metabolites in response to
fire was found. Chlorophylls and carotenoid contents decreased within a
short temporal scale, but their concentrations returned to pre-event
conditions one-year after disturbance. Concentrations of phenolic
compounds and tannins in burnt plants increased up to two years after
EB. The fast-metabolic response evidenced the plant tolerance to fire.
These metabolites could be used as bioindicators of vegetation
resilience after fire.