Chemical screening pipeline for identification of specific plant autophagy modulators ($) (Plant Physiol)

Autophagy is a recycling pathway that supports numerous processes, from nutrient remobilization to abiotic and biotic stress responses. Dauphinee, Cardoso et al. have developed a multi-step pathway that allows them to screen for inhibitors of autophagy in order to build a repertoire of new tools. For a high-throughput screen of autophagy inhibition, they start by looking at a decrease in fluorescence of a marker due to its transport into the lytic vescicle, using cultured tobacco cells. Candidates are next screened in whole plants using a tandem tag assay: one fluorescent tag is pH sensitive so the ratio of fluorescence from the two tags reveals the distribution of the reporter, hence extent of nitrogen-starvation induced autophagy. They followed this with a time-course assay and a check for specificity, leading to the identification of several  promising new autophagy inhibitors. (Summary by Mary Williams) Plant Physiol. 10.1104/pp.19.00647