The hydroxyproline O-arabinosyltransferase FIN4 is required for tomato pollen intine development

Abstract

The pollen grain cell wall is a highly specialized structure composed of distinct layers formed through complex developmental pathways. The production of the innermost intine layer, composed of cellulose, pectin and other polymers, is particularly poorly understood. Here we demonstrate an important and specific role for the hydroxyproline O-arabinosyltransferase (HPAT) FIN4 in tomato intine development. HPATs are plant-specific enzymes which initiate glycosylation of certain cell wall structural proteins and signaling peptides. FIN4 was expressed throughout pollen development in both the developing pollen and surrounding tapetal cells. A germination and the process of intine formation involves dynamic changes in the developing pollen cell wall.

New Advances in the Study of Regulation of Tomato Flowering-Related Genes Using Biotechnological Approaches

“…Pollen grains are developed from microspores in the microsporangium of an anther. The cell wall of a mature pollen grain is a multilayered structure consisting of sporopollenin-based exine [173] and cellulose-based intine [174,175]. Pollen development and maturation involve multiple cellular changes mediated via the precisely organized regulation of gene expression.…”