Isolation and characterization of formaldehyde-responsive genes from golden pothos (Epipremnum aureum)

Abstract

Plants absorb and metabolize formaldehyde, a C-1 compound that is one of the main indoor air pollutants. To elucidate the molecular mechanism of formaldehyde metabolism in plants, we isolated formaldehyde-responsive genes from golden pothos by means of GeneFishing PCR. We focused on the immediate-early response genes following formaldehyde treatment. Two full length cDNA sequences corresponding to a putative class II chitinase and a hypothetical novel protein, which we termed DEG2, were generated by rapid amplification of cDNA ends (RACE). The chitinase, which we designated EaCHI1, was up-regulated in the leaves and stems, whereas DEG2 was up-regulated in the leaves and roots of formaldehyde-treated golden pothos. Phylogenetic analysis showed that putative class II chitinases were split into two groups, monocot and dicot. EaCHI1 belonged to the former group, occupying the most basal level among the monocot chitinases analyzed. The identification of chitinase as a formaldehyde-responsive gene suggests a novel physiological role for this enzyme in plant carbon metabolism and environmental responses. The DEG2 sequence was not similar to any known protein sequence.