Ethylene modulates the dynamics of translation via GCN2 and EIN2 in Arabidopsis under submergence

ABSTRACT: General translational repression is predicted as a key process to reduce energy consumption under hypoxia. We have previously showed that mRNA loading onto polysome is reduced in Arabidopsis under submergence. Here, we showed that plant stress activated GCN2 (general control nonderepressible 2) can phosphorylate eIF2a (Eukaryotic Initiation Factor 2a) in Arabidopsis under submergence, and this process is reversible after desubmergence. Compared to the wild-type, the reduction in polysome loading during submergence was less severe in the gcn2 mutant. Transgenic lines overexpressing GCN2 had more ATP and conferred better tolerance under submergence, suggesting that GCN2 might modulate the dynamics of translation to adjust the energy homeostasis under hypoxia. Interestingly, GCN2-eIF2a signaling was activated by ethylene under submergence. However, GCN2 activity was not affected in ein2-5 and eil1ein3 under submergence, suggesting that GCN2 activity was regulated by noncanonical ethylene signaling. In addition, the polysome loading was retained in both ein2-5 and etr1-1 under submergence, implying that ethylene modulated the dynamic translation under submergence via EIN2 and GCN2. Notably, our NGS analysis also demonstrated that EIN2 and GCN2 regulated the translation of 23 core hypoxia genes as well as 53% translational repressed genes under submergence. On the other hand, EIN2 and GCN2 also affected the expression of genes involved in hypoxic response, ethylene response, biotic stress and negative regulation of cytokinin signaling. Taken together, these demonstrated that entrapped ethylene triggers GCN2 and EIN2 to ensure the translation of stress required proteins under submergence and also provide a step stone for future investigation how eukaryotic cells modulate the translation to response for the changeable environments.

ORGANISM(S): Arabidopsis thaliana

PROVIDER: GSE149414 | GEO | 2022/06/08

REPOSITORIES: GEO