Cytological attributes of storage tissues in nematode and eriophyid galls: pectin and hemicellulose functional insights.

Abstract

Cell walls and protoplast may work together or distinctly in the establishment of the functional profiles of gall tissue compartments. This presumption is herein evaluated in three gall systems by immunocytochemical and ultrastructural analyses. The common storage tissues (CSTs) of leaf galls induced by Eriophyidae on Miconia ibaguensis leaves and by Ditylenchus gallaeformans on M. ibaguensis and M. albicans have rigid and porous cell walls due to their composition of pectins. Hemicelluloses in CST cell walls are scarcer when compared to the cell walls of the control leaves, being functionally compensated by rigid pectate gels. The typical nutritive tissues (TNTs) in galls induced by Ditylenchus gallaeformans are similar to promeristematic and secretory cells regarding their enriched cytoplasm, several mitochondria, and proplastids, as well as multivesicular and prolamellar bodies in cell membranes. The cytological features of the feeding cells of Eriophyidae galls indicate that they are not as metabolically active as the cells of the TNT in nematode galls. However, their cell wall composition suggests more plasticity and porosity than the cells of the TNT, which can compensate the less production of nutrients with more transport. The ultrastructural and immunocytochemical profiles of CST cells reveal functional similarities, which are independent of the taxa of the gall inducer or of the host plant. Despite their analogous functionalities, the protoplast and cell wall features of TNT cells of nematode galls and of the feeding cells of the Eriophyidae galls are distinct, and work out through different strategies toward keeping gall developmental site active.