Establishment of monitoring methods for autophagy in XXXX reveals autophagic recycling of chloroplasts and root plastids during energy limitation.

@entity958 @entity2307 @entity1053 @entity375 @entity579
UNASSIGNED: Autophagy is an intracellular process leading to vacuolar or lysosomal degradation of cytoplasmic components in eukaryotes. Establishment of proper methods to monitor autophagy was a key step to uncover its role in organisms such as @entity375 , mammals and @entity958 , in which chloroplastic proteins were found to be recycled by autophagy. Chloroplast recycling has been predicted to function in nutrient remobilization for growing organs or grain filling in cereal crops. Here, to develop our understanding of autophagy in cereals, we established monitoring methods for chloroplast autophagy in @entity579 ( @entity579 ). We generated transgenic @entity579 expressing fluorescent protein (FP)-OsATG8 fusions as autophagy markers. FP-ATG8 signals were delivered into the vacuolar lumen in living cells of roots and leaves mainly as vesicles corresponding autophagic bodies. This phenomenon was not observed upon the addition of @entity2307 , an inhibitor of autophagy, or in an AUTOPHAGY7 knockout mutant. Markers for the chloroplast stroma, stromal FP and FP-labeled Rubisco, were delivered via a type of autophagic body called the @entity1053 ( @entity1053 ) in the same manner. @entity1053 production in excised leaves was suppressed by supply of external Suc or light. The release of free FP due to autophagy-dependent breakdown of FP-labeled Rubisco was induced during accelerated senescence in individually-darkened leaves. In roots, non-green plastids underwent both @entity1053 -mediated and entire-organelle types of autophagy. Therefore, our newly developed methods to monitor autophagy directly demonstrated autophagic degradation of leaf chloroplasts and root plastids in @entity579 plants and its induction during energy limitation.
