Multivesicular bodies differentiate exclusively in nutritive fast-dividing cells in Marcetia taxifolia galls.

Marcetia taxifolia (A. St.-Hil.) DC. hosts two gall morphotypes, a pistil-shaped gall induced by a Cecidomyiidae (Diptera) and a fusiform stem gall induced by a Lepidoptera. The cytological study of these galls aimed to answer how the difference in nutritive tissues of Diptera and Lepidoptera galls could be explained on cytological basis. The nutritive tissues of lepidopteran galls have a fast-dividing cell zone, the storage nutritive tissue, which replaces the cells of the typical nutritive tissue, where the larvae feed. The differentiation of multivesicular bodies in the plasma membrane occurred exclusively in these fast-dividing cells of the lepidopteran galls, evidencing the meristematic condition of such tissue. The accumulation of reactive oxygen species (ROS) analyzed in situ in the nutritive cells is not sufficient to induce programmed cell death (PCD), as the cells of M. taxifolia have plastoglobules and accumulate polyphenols and terpenoids, which are diagnostic defenses against oxidative stress. The two taxa of galling insects have different nutritional requirements, thus inducing specific cytoplasm-enriched cells on their nutritive tissues.