Reduction in carotenoid and chlorophyll content induced by the sweet potato whitefly, Bemisia tabaci

Abstract

The sweet potato whitefly, Bemisia tabaci (Hemiptera: Aleyrodidae) B biotype, induces pigmentation changes in fruit and leaves including tomato-irregular-ripening disorder and squash-silverleaf disorder. We compared carotenoid and chlorophyll content of symptomatic and asymptomatic plant tissue. Symptomatic tissue from tomato fruit had 69% and 79% less lycopene (red pigment) and its precursor phytoene, respectively, than asymptomatic tissue. Heavily silvered squash leaves had 63% and 68% less chlorophyll a and b (green pigments), respectively, than healthy leaves. Squash leaves with silvering also had 42–67% lower levels of the carotenoids, β-carotene, all-trans-violaxanthin and lutein. These results suggest that infestation by the sweet potato whitefly inhibits the accumulation of carotenoids and chlorophylls which are both synthesized through the non-mevalonate pathway.