Graduate Research Assistant Purdue University West Lafayette, Indiana
Body of Abstract: During flowering plant reproduction, intercellular communication between the male pollen tube and female synergid cell is necessary to induce pollen tube bursting and successful fertilization. The MILDEW RESISTANCE LOCUS O (MLO) calcium channel NORTIA (NTA) participates in male-female signaling during pollen tube reception. During pollen tube reception, NTA is held in the Golgi and redistributed to the filiform apparatus, the membrane rich region at the micropylar end of the synergid, in a signaling pathway dependent on the receptor-like kinase FERONIA (FER). Constitutive filiform apparatus localization of NTA using the MLO1 C-terminus (faNTA) can complement nta-1 infertility and partially complement fer-1 infertility, demonstrating that filiform apparatus localization of NTA is sufficient to induce pollen tube bursting. When ectopically expressed in animal cells, NTA remains Golgi localized and faNTA plasma membrane localized, suggesting that the mechanism of MLO trafficking is conserved between plants and animals. When NTA is mutated in either the calmodulin binding domain or predicted palmitoylation sites, it is not fully retained in the Golgi and partially localizes with the filiform apparatus prior to pollen tube approach. Further work will be done to elucidate the role of the calmodulin binding domain in MLO trafficking and determine whether palmitoylation is required for Golgi retention.