Modulation of Host Endocycle During Plant-Biotroph Interactions.

Recent studies have revealed that several mutualistic and parasitic biotrophic microbes induce a cell cycle variant termed the endocycle in host cells to support their growth and reproduction. Endoreduplication is a process in which cells successively replicate their genomes without mitosis resulting in an increase in nuclear DNA ploidy. Depending on the interaction, endoreduplication can support biotroph colonization and feeding structure initiation/development, and/or serve as a mechanism to support enhanced metabolic demands of the microbe. When endoreduplication is inhibited in these interactions, biotroph growth or development is compromised. In this review, we summarize the molecular machinery known to mediate endocycle control in plants and highlight the role of these core components in feeding site establishment and/or nutrient acquisition for a diverse set of plant biotrophs.