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The low oxygen, oxidative and osmotic stress responses synergistically act through the ethylene response factor VII genes RAP 2.12 , RAP 2.2 and RAP 2.3
Author(s) -
Papdi Csaba,
PérezSalamó Imma,
Joseph Mary Prathiba,
Giuntoli Beatrice,
Bögre László,
Koncz Csaba,
Szabados László
Publication year - 2015
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1111/tpj.12848
Subject(s) - transcription factor , arabidopsis , microbiology and biotechnology , chemistry , gene silencing , osmotic shock , mutant , gene expression , gene , biology , biochemistry
Summary The ethylene response factor VII ( ERF ‐ VII ) transcription factor RELATED TO APETALA 2.12 ( RAP 2.12) was previously identified as an activator of the ALCOHOL DEHYDROGENASE 1 promoter::luciferase ( ADH 1‐ LUC ) reporter gene. Here we show that overexpression of RAP 2.12 and its homologues RAP 2.2 and RAP 2.3 sustains ABA ‐mediated activation of ADH 1 and activates hypoxia marker genes under both anoxic and normoxic conditions. Inducible expression of all three RAP 2s conferred tolerance to anoxia, oxidative and osmotic stresses, and enhanced the sensitivity to abscisic acid ( ABA ). Consistently, the rap2.12‐2 rap2.3‐1 double mutant showed hypersensitivity to both submergence and osmotic stress. These findings suggest that the three ERF ‐ VII ‐type transcription factors play roles in tolerance to multiple stresses that sequentially occur during and after submergence in Arabidopsis. Oxygen‐dependent degradation of RAP 2.12 was previously shown to be mediated by the N‐end rule pathway. During submergence the RAP 2.12, RAP 2.2 and RAP 2.3 are stabilized and accumulates in the nucleus affecting the transcription of stress response genes. We conclude that the stabilized RAP 2 transcription factors can prolong the ABA ‐mediated activation of a subset of osmotic responsive genes (e.g. ADH 1 ). We also show that RAP 2.12 protein level is affected by the REALLY INTERESTING GENE ( RING ) domain containing SEVEN IN ABSENTIA of Arabidopsis thaliana 2 ( SINAT 2). Silencing of SINAT 1/2 genes leads to enhanced RAP 2.12 abundance independently of the presence or absence of its N‐terminal degron. Taken together, our results suggest that RAP 2.12 and its homologues RAP 2.2 and RAP 2.3 act redundantly in multiple stress responses. Alternative protein degradation pathways may provide inputs to the RAP 2 transcription factors for the distinct stresses.