Autophagy contributes to regulation of the hypoxia response during submergence in Arabidopsis thaliana

In mammals, hypoxia rapidly stimulates autophagy as a cell survival response. Here, we examine the function of autophagy in the regulation of the plant response to submergence, an abiotic stress that leads to hypoxia and anaerobic respiration in plant cells.

In Arabidopsis thaliana , submergence induces the transcription of autophagy-related ( ATG ) genes and the formation of autophagosomes. Consistent with this, the autophagy-defective ( atg ) mutants are hypersensitive to submergence stress and treatment with ethanol, the end product of anaerobic respiration. Upon submergence, the atg mutants have increased levels of transcripts of anaerobic respiration genes ( alcohol dehydrogenase 1, ADH1 and pyruvate decarboxylase 1, PDC1 ), but reduced levels of transcripts of other hypoxia- and ethylene-responsive genes.