A phenological trick and cell wall bricks toward adaptive strategies of Mimosa tenuiflora-Lopesia mimosae interaction in Caatinga environment

Abstract

Caatinga environment tends to impose constraints on the phenology and development of the host plants and their associated galls. Phenological synchronism in Mimosa tenuiflora-Lopesia mimosae system, and anatomical, cytometric, and immunocytochemical analyzes reveal strategies of the gall survivorship in Caatinga. As phenological strategies, the peak of young galls synchronizes with leaf sprouting in the rainy season, and the reproductive phase is concomitant to gall senescence in the dry season. As structural strategies, the reorganization and the compartmentalization of gall tissues assist gall development in response to environmental constraints, and the predominance of periclinal cell elongation determined the gall bivalve shape. The distribution of pectins, glycoproteins, and hemicelluloses modulate cell walls toward favoring gall resistance to drought stress. The homogalacturonans confer high porosity to the cell walls of the typical nutritive tissue. The galactans and arabinans confer flexibility to the cell walls of the common storage tissue favoring tolerance to drought. The xylogalacturonans and heteromannans in the cell walls of the typical nutritive tissue are associated with nutritive reserves directed to the galling insect. The phenological synchronism, modulation of leaf tissues and cell wall components confer water and nutritional resources to the Lopesia mimosae microenvironment, the gall.