Dataset Information

The miR396-GRFs Module Mediates Brassinosteroid-Prevented Photooxidative 1 Damage during Seedling De-etiolation in Arabidopsis

ABSTRACT: The developmental switch from skotomorphogenesis to photomorphogenesis is critical for the survival and growth of plants, but its regulatory mechanism remains unclear. Here, we report that the steroid hormone brassinosteroids (BRs) play crucial roles in the transition from skotomorphogenesis to photomorphogenesis by regulating chlorophyll biosynthesis to promote the greening of etiolated seedlings upon light exposure. Seedlings of BR-deficient mutant det2-1 accumulated excess protochlorophyllide when grown in darkness, resulting in photo-oxidative damage upon exposure to light. Conversely, the gain-of-function mutant bzr1-1D suppressed the protochlorophyllide-accumulated phenotype of det2-1, thereby promoting greening of etiolated seedlings. Genetic analysis indicated that phytochrome-interacting factors (PIFs) were required for BZR1-promoted seedlings greening. Furthermore, we revealed that the GROWTH REGULATING FACTOR 7 (GRF7) and GRF8 were induced by BZR1 and PIF4 to repress the chlorophyll biosynthesis and promote seedling greening. Suppression the functions of GRFs by overexpressing microRNA396a (miR396a) caused the high-accumulated photochlorophyllide in darkness and more serious photobleach upon light exposure. Additionally, BZR1, PIF4 and GRF7 interact with each other and precisely regulate the expression of chlorophyll biosynthetic genes. Our findings revealed an essential role of brassinosteroid in promoting seedling development and survival during the critical initial emergence of seedlings from subterranean darkness to sunlight.

ORGANISM(S): Arabidopsis thaliana

PROVIDER: GSE149834 | GEO | 2020/06/01

REPOSITORIES: GEO

ACCESS DATA

Similar Datasets

Project description:The proper transition between the skotomorphogenic and photomorphogenic developmental programs is key for seedling survival and it is therefore tightly regulated. Besides light, which is the major cue that triggers this transition, several hormone pathways participate in this control, mainly antagonizing the light effect. Two of these hormones are gibberellins (GA) and brassinosteroids (BR). Both hormones promote the skotomorphogenesis and prevent photomorphogenesis, as evidenced by the partially de-etiolated phenotype caused by GA or BR deficiency, or by a blockage in the respective signaling pathways. We have previously shown that BR mediate GA activity in the control of this transition. For instance, treatment of dark-grown, GA-deficient seedlings with BRs was able to partially restore morphological phenotypes such as hypocotyl growth, and importantly to restore completely the molecular phenotype of CAB2 and RbcS gene expression. On the contrary, GA-treatment did not alter the same phenotypes in the BR deficient det2 mutant. Thus, the aim of this study was to investigate to what extent BRs mediate GA activity in dark-grown seedlings, and for that purpose we have the examined global changes in gene expression caused by treatment with GA and BRs in BR- and GA-deficient seedlings, respectively. We performed two sets of experiments, each one including three different samples. The first experiment included dark-grown, WT Col-0 mock-treated seedlings, or seedlings treated with either the GA biosynthesis inhibitor paclobutrazol (PAC) or with PAC+epibrassinolide (EBR). In this experiment, PAC samples were labelled with Cy3 and compared to WT and PAC+EBR samples, which were labelled with Cy5. Two biological repeast were performed. The second experiment included dark-grown, WT Col-0 seedlings and the det2-1 mutant, which was either mock-treated or treated with GA3. Two biological replicates were performed, in the first one the WT and det2-1+GA3 were labelled with Cy3 and the det2-1 sample with Cy5. The reverse labelling was used in the second replicate.

Dataset Information

The miR396-GRFs Module Mediates Brassinosteroid-Prevented Photooxidative 1 Damage during Seedling De-etiolation in Arabidopsis

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure