Abstract
Because plants cannot move from the habitat, the supply of nutrients can vary by environmental changes. Several responses to nutrient limitation were observed in plants. Among them, autophagy is the degradation system that is induced upon starvation. We developed previously a method to quantify the autophagic degradation using a red-fluorescent reporter protein. This system was recently improved using color-convertible fluorescent protein to distinguish the synthesis and degradation of the reporter protein. Using this system we investigated the effect of phosphite, which is a non-metabolizable analog of phosphate, on the induction of starvation dependent autophagy. We observed that the phosphite supresses both the autophagy induction and decrease in protein synthesis specifically under phosphate limitation condition. Independently, we observed that a sucrose transporter, which is localized to the trans-Golgi network, specifically degraded upon sugar starvation possibly by autophagy. In this symposium, we present these recent findings and discuss the pathways for the induction of intracellular degradation system and various nutritional deficiencies.
