Title: Ovate family protein1 interaction with BLH3 regulates transition timing from vegetative to reproductive phase in Arabidopsis

Abstract

We study the Three-Amino-acid-Loop-Extension(TALE) homeodomain transcription factor BLH3 that regulates timing of transition from vegetative to reproductive phase. Previous preliminary results obtained using large-scale yeast two-hybrids indicate that BLH3 protein possibly interact with Ovate Family Proteins(OFPs) transcription co-regulators. Nevertheless, it is uncertain whether OFP1–BLH3 complex is involved in regulation of timing of transition from vegetative to reproductive phase in Arabidopsis. The interaction between BLH3 and OFP1 was re-tested and verified by a yeast two-hybrid system. We found that the BLH3–OFP1 interaction was mainly mediated through the BLH3 homeodomain. Meanwhile, this interaction was further confirmed by bimolecular fluorescence complementation (BiFC) in vivo. In addition, by establishing protoplast transient expression, we discovered that BLH3 acts as a transcriptional activator, whereas OFP1 functioned as a repressor. The interactions between OFP1 and BLH3 can reduce BLH3 transcriptional activity. The ofp1 mutant lines and blh3 mutant lines, OFP1 overexpress lines and BLH3 overexpress lines can both influence timing of transition from vegetative to reproductive phase. Furthermore, 35s:OFP1/blh3 plants exhibited flowering and leaf quantity similar to that of the wild-type controls. 35s:BLH3/ofp1 plants flowered earlier and had less leaves than wild-type controls, indicating that OFP1 protein might depend partially on BLH3 in its function to regulatemore » the timing of transition from vegetative to reproductive phase. In conclusion, these results support our assumption that, by interacting with OFP1, BLH3 forms a functional protein complex that controls timing of progression from vegetative to reproductive phase, and OFP1 might negatively regulate BLH3 or the BLH-KNOX complex, an important interaction for sustaining the normal transition from vegetative to reproductive phase.« less

Authors:

Zhang, Liguo ^[1]; Zhang, Xiaofei ^[2]; Ju, Hanxun ^[3]; Chen, Jingui ^[4]; Wang, Shucai ^[5]; Wang, Hemeng ^[3]; Zhao, Yuanling ^[6]; Chang, Ying ^[3]

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+ Show Author Affiliations

1. Northeast Agricultural University, Harbin (China); Heilongjiang Academy of Agricultural Sciences, Harbin (China)
2. Guangxi University, Nanning (China)
3. Northeast Agricultural University, Harbin (China)
4. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
5. Northeast Normal University, Changchun (China)
6. Heilongjiang Academy of Agricultural Sciences, Harbin (China)

Publication Date:

Sat Jan 23 00:00:00 EST 2016

Research Org.:

Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)

Sponsoring Org.:

USDOE; National Nature Science Foundation of China

OSTI Identifier:

1311260

Grant/Contract Number:  

AC05-00OR22725; 31370221

Resource Type:

Accepted Manuscript

Journal Name:

Biochemical and Biophysical Research Communications

Additional Journal Information:

Journal Volume: 470; Journal Issue: 3; Journal ID: ISSN 0006-291X

Publisher:

Elsevier

Country of Publication:

United States

Language:

English

Subject:

59 BASIC BIOLOGICAL SCIENCES; OFP1; BLH3; Vegetative to reproductive phase; Protein-protein interaction; Arabidopsis