Expression of turtle riboflavin-binding protein represses mitochondrial electron transport gene expression and promotes flowering in Arabidopsis

BMC Plant Biology

Research Article

Xiaobing Wang¹  Liang Li¹  Dan Shen¹  Li-Ping Han¹  Yueyue Zhu¹  Li Hu¹  Hongtao Ji¹  Manyu Xu¹  Jun Ge¹  Hansong Dong¹ 

[1]Department of Plant Pathology, Nanjing Agricultural University and State Ministry of Education Key Laboratory of Integrated Management of Crop Pathogens and Insect Pests, 210095, Nanjing, China

关键词: Rotenone;    Flavin;    Shoot Apex;    H2O2 Concentration;    Flavin Adenine Dinucleotide;   

DOI  :  10.1186/s12870-014-0381-5

 received in 2014-08-20, accepted in 2014-12-11,  发布年份 2014

来源: Springer

【 摘 要 】

BackgroundRecently we showed that de novo expression of a turtle riboflavin-binding protein (RfBP) in transgenic Arabidopsis increased H2O2 concentrations inside leaf cells, enhanced the expression of floral regulatory gene FD and floral meristem identity gene AP1 at the shoot apex, and induced early flowering. Here we report that RfBP-induced H2O2 presumably results from electron leakage at the mitochondrial electron transport chain (METC) and this source of H2O2 contributes to the early flowering phenotype.ResultsWhile enhanced expression of FD and AP1 at the shoot apex was correlated with early flowering, the foliar expression of 13 of 19 METC genes was repressed in RfBP-expressing (RfBP+) plants. Inside RfBP+ leaf cells, cytosolic H2O2 concentrations were increased possibly through electron leakage because similar responses were also induced by a known inducer of electron leakage from METC. Early flowering no longer occurred when the repression on METC genes was eliminated by RfBP gene silencing, which restored RfBP+ to wild type in levels of FD and AP1 expression, H2O2, and flavins. Flowering was delayed by the external riboflavin application, which brought gene expression and flavins back to the steady-state levels but only caused 55% reduction of H2O2 concentrations in RfBP+ plants. RfBP-repressed METC gene expression remedied the cytosolic H2O2 diminution by genetic disruption of transcription factor NFXLl and compensated for compromises in FD and AP1 expression and flowering time. By contrast, RfBP resembled a peroxisomal catalase mutation, which augments the cytosolic H2O2, to enhance FD and AP1 expression and induce early flowering.ConclusionsRfBP-repressed METC gene expression potentially causes electron leakage as one of cellular sources for the generation of H2O2 with the promoting effect on flowering. The repressive effect on METC gene expression is not the only way by which RfBP induces H2O2 and currently unappreciated factors may also function under RfBP+ background.

【 授权许可】

Unknown   
© Li et al.; licensee BioMed Central. 2014. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.