The atrzf1 mutation of the novel RING-type E3 ubiquitin ligase increases proline contents and enhances drought tolerance in Arabidopsis

► AtRZF1 gene is regulated by dehydration stress. ► AtRZF1 is a functional E3 ubiquitin ligase. ► Overexpression of AtRZF1 confers high sensitivity to drought stress. ► AtRZF1 participates negatively in proline production under drought condition.