Autophagy mutants show delayed chloroplast development during de‐etiolation in carbon limiting conditions

• DOI: 10.1111/tpj.15452
• Publication Date: 2021-08-08T16:57:38Z
• Authors: Akila Wijerathna‐...; Santiago Signorelli; Ricarda Fenske; Diep R. Ganguly; Elke Stroeher; Lei Li; Barry J. Pogson; Owen Duncan; A. Harvey Millar
• Keywords: Etiolation; Limiting

SUMMARY Autophagy is a conserved catabolic process that plays an essential role under nutrient starvation conditions and influences different developmental processes. We observed seedlings of autophagy mutants ( atg2 , atg5 atg7 atg9 ) germinated in the dark showed delayed chloroplast development following illumination. The was characterized by decrease photosynthetic chlorophyll biosynthetic proteins, lower content, reduced size, increased levels proteins involved lipid biosynthesis. Confirming biological impact these differences, performance impaired 12 h post‐illumination. while gene expression for machinery during de‐etiolation largely unaffected atg mutants, several genes photosystem assembly were transcriptionally downregulated. also investigated if could be explained import to or triglyceride (TAG) turnover. limitations imposed trigalactosyldiacylglycerol1 are unlikely explain delay development. However, we found TAG mobility triacylglycerol lipase mutant sugardependent1 significantly affected de‐etiolation. Moreover, carbon resources exacerbated slow greening phenotype whereas higher had opposite effect. This work suggests lack limits de‐etiolation, this limited turnover (lipophagy) physically energetically restrains