Time: 10:00 am
Day/Date: July 6th, 2017 (Thursday)
Host PI: Prof. Alberto Macho
Venue: PSC Auditorium
Plant Resistance (R) proteins are immune receptors that recognize pathogen effectors and trigger rapid defense responses, namely effector triggered immunity (ETI). R protein mediated pathogen resistance is usually race specific. During the plant-pathogen coevolution, plant genomes accumulated large number of R genes. Even though plant R genes provide important natural resources for breeding disease resistant crop, R gene is considered a double edged sword because there is a cost for plant genome to bear R genes. Mis-regulation of plant R genes leads to the developmental defect, such as stunted growth and reduced fertility. In the past decade, many miRNAs were identified targeting various R genes in plant genomes. Among them, miR482/2118 family is conserved among both dicot and monocot while more miRNA families are specific to narrow range of plant species, like miR6019/6020 family. These miRNAs usually target R transcript regions encoding conserved protein motifs. And evolutionary analysis indicates they arise from inverted duplication of R gene fragments. During pathogen infection, the miRNA mediated repression of R gene is inhibited and R gene expression is induced, thus miRNA is considered a molecular scabbard for R gene. The TMV-N-miR6019 interaction is employed as a model system to discuss how the molecular scabbard help plants to fine tuning the function of their sword.