EXO70I Is Required for Development of a Sub-domain of the Periarbuscular Membrane during Arbuscular Mycorrhizal Symbiosis.

摘要: Summary In eukaryotic cells, polarized secretion mediated by exocytotic fusion of membrane vesicles with the plasma is essential for spatially restricted expansion and delivery molecules to specific locations at and/or cell surface. The EXOCYST complex central this process, in yeast, regulation EXO70 subunit influences exocytosis cargo specificity [1, 2]. contrast yeast mammalian plants have upwards 23 genes largely unknown roles [3–6]. During arbuscular mycorrhizal (AM) symbiosis, deposition plant periarbuscular (PAM) around fungal arbuscule creates an intracellular interface between symbionts. PAM has two major sub-domains, symbiosis-specific transporter proteins are localized branch domain [7–11]. Currently, mechanisms cellular machinery involved biogenesis unknown. Here, we identify EXO70I protein present exclusively forming AM symbiosis. Medicago truncatula exo70i mutants unable support normal development, incorporation PAM-resident ABC transporters, STR STR2, limited. branching, located zones adjacent hyphal tips where it interacts Vapyrin [12–14], a plant-specific required development. We conclude that provides capacity necessary development main functional sub-domain PAM. Furthermore, other eukaryotes, EXO70s evolved distinct specificities interaction partners fulfill their specialized secretory requirements.