BHLH Transcription Factor BHLH115 Regulates Iron Homeostasis in Arabidopsis Thaliana

Overview

Journal J Exp Bot

Publisher Oxford University Press

Specialty Biology

Date 2017 Apr 4

PMID 28369511

Citations 68

Authors

Gang Liang

Huimin Zhang

Xiaoli Li

Qin Ai

Diqiu Yu

Affiliations

Soon will be listed here.

Abstract

Iron (Fe) deficiency is a limiting factor for the normal growth and development of plants, and many species have evolved sophisticated systems for adaptation to Fe-deficient environments. It is still unclear how plants sense Fe status and coordinate the expression of genes responsive to Fe deficiency. In this study, we show that the bHLH transcription factor bHLH115 is a positive regulator of the Fe-deficiency response. Loss-of-function of bHLH115 causes strong Fe-deficiency symptoms and alleviates expression of genes responsive to Fe deficiency, whereas its overexpression causes the opposite effect. Chromatin immunoprecipitation assays confirmed that bHLH115 binds to the promoters of the Fe-deficiency-responsive genes bHLH38/39/100/101 and POPEYE (PYE), which suggests redundant molecular functions with bHLH34, bHLH104, and bHLH105. This is further supported by the fact that the bhlh115-1 mutant was complemented by overexpression of any of bHLH34, bHLH104, bHLH105, and bHLH115. Further investigations determined that bHLH115 could interact with itself and with bHLH34, bHLH104, and bHLH105. Their differential tissue-specific expression patterns and the severe Fe deficiency symptoms of multiple mutants supported their non-redundant biological functions. Genetic analysis revealed that bHLH115 is negatively regulated by BRUTUS (BTS), an E3 ligase that can interact with bHLH115. Thus, bHLH115 plays key roles in the maintenance of Fe homeostasis in Arabidopsis thaliana.

Citing Articles

Genome-wide characterization and expression analysis of the bHLH gene family in response to abiotic stresses in Zingiber officinale Roscoe.

Liu D, Zhang P, Zhou T, Wu Y, Yuan M, Zhang X BMC Genomics. 2025; 26(1):143.

PMID: 39948473 PMC: 11827417. DOI: 10.1186/s12864-025-11284-8.

The BRUTUS iron sensor and E3 ligase facilitates soybean root nodulation by monoubiquitination of NSP1.

Ren Z, Zhang L, Li H, Yang M, Wu X, Hu R Nat Plants. 2025; .

PMID: 39900829 DOI: 10.1038/s41477-024-01896-5.

A bHLH Transcription Factor Confers Salinity Stress Tolerance in .

Fang Q, Wu D, Sun H, Wang L, Liu Y, Mei W Plant Direct. 2024; 8(12):e70029.

PMID: 39691550 PMC: 11651711. DOI: 10.1002/pld3.70029.

Genome-Wide Identification of Basic Helix-Loop-Helix () Family in Peanut: Potential Regulatory Roles in Iron Homeostasis.

Shi G, Zhang Z, Li J Int J Mol Sci. 2024; 25(22).

PMID: 39596126 PMC: 11594023. DOI: 10.3390/ijms252212057.

Ectopic expression of HvbHLH132 from hulless barley reduces cold tolerance in transgenic Arabidopsis thaliana.

Hao Y, Su J, Cui Y, Wu K Plant Cell Rep. 2024; 43(12):297.

PMID: 39585367 DOI: 10.1007/s00299-024-03382-w.

References

Li X, Zhang H, Ai Q, Liang G, Yu D . Two bHLH Transcription Factors, bHLH34 and bHLH104, Regulate Iron Homeostasis in Arabidopsis thaliana. Plant Physiol. 2016; 170(4):2478-93. PMC: 4825117. DOI: 10.1104/pp.15.01827. View

Clough S, Bent A . Floral dip: a simplified method for Agrobacterium-mediated transformation of Arabidopsis thaliana. Plant J. 1999; 16(6):735-43. DOI: 10.1046/j.1365-313x.1998.00343.x. View

Colangelo E, Guerinot M . The essential basic helix-loop-helix protein FIT1 is required for the iron deficiency response. Plant Cell. 2004; 16(12):3400-12. PMC: 535881. DOI: 10.1105/tpc.104.024315. View

Hell R, Stephan U . Iron uptake, trafficking and homeostasis in plants. Planta. 2003; 216(4):541-51. DOI: 10.1007/s00425-002-0920-4. View

McLean E, Cogswell M, Egli I, Wojdyla D, de Benoist B . Worldwide prevalence of anaemia, WHO Vitamin and Mineral Nutrition Information System, 1993-2005. Public Health Nutr. 2008; 12(4):444-54. DOI: 10.1017/S1368980008002401. View

Long T, Tsukagoshi H, Busch W, Lahner B, Salt D, Benfey P . The bHLH transcription factor POPEYE regulates response to iron deficiency in Arabidopsis roots. Plant Cell. 2010; 22(7):2219-36. PMC: 2929094. DOI: 10.1105/tpc.110.074096. View

Wang N, Cui Y, Liu Y, Fan H, Du J, Huang Z . Requirement and functional redundancy of Ib subgroup bHLH proteins for iron deficiency responses and uptake in Arabidopsis thaliana. Mol Plant. 2012; 6(2):503-13. DOI: 10.1093/mp/sss089. View

Palmer C, Hindt M, Schmidt H, Clemens S, Guerinot M . MYB10 and MYB72 are required for growth under iron-limiting conditions. PLoS Genet. 2013; 9(11):e1003953. PMC: 3836873. DOI: 10.1371/journal.pgen.1003953. View

Saleh A, Alvarez-Venegas R, Avramova Z . An efficient chromatin immunoprecipitation (ChIP) protocol for studying histone modifications in Arabidopsis plants. Nat Protoc. 2008; 3(6):1018-25. DOI: 10.1038/nprot.2008.66. View

10.

Zhao M, Song A, Li P, Chen S, Jiang J, Chen F . A bHLH transcription factor regulates iron intake under Fe deficiency in chrysanthemum. Sci Rep. 2014; 4:6694. PMC: 4208034. DOI: 10.1038/srep06694. View

11.

Zhao Q, Ren Y, Wang Q, Yao Y, You C, Hao Y . Overexpression of MdbHLH104 gene enhances the tolerance to iron deficiency in apple. Plant Biotechnol J. 2016; 14(7):1633-45. PMC: 5066684. DOI: 10.1111/pbi.12526. View

12.

Curie C, Cassin G, Couch D, Divol F, Higuchi K, Le Jean M . Metal movement within the plant: contribution of nicotianamine and yellow stripe 1-like transporters. Ann Bot. 2008; 103(1):1-11. PMC: 2707284. DOI: 10.1093/aob/mcn207. View

13.

Selote D, Samira R, Matthiadis A, Gillikin J, Long T . Iron-binding E3 ligase mediates iron response in plants by targeting basic helix-loop-helix transcription factors. Plant Physiol. 2014; 167(1):273-86. PMC: 4281009. DOI: 10.1104/pp.114.250837. View

14.

Varotto C, Maiwald D, Pesaresi P, Jahns P, Salamini F, Leister D . The metal ion transporter IRT1 is necessary for iron homeostasis and efficient photosynthesis in Arabidopsis thaliana. Plant J. 2002; 31(5):589-99. DOI: 10.1046/j.1365-313x.2002.01381.x. View

15.

Harrison P, Arosio P . The ferritins: molecular properties, iron storage function and cellular regulation. Biochim Biophys Acta. 1996; 1275(3):161-203. DOI: 10.1016/0005-2728(96)00022-9. View

16.

Kobayashi T, K Nishizawa N . Iron uptake, translocation, and regulation in higher plants. Annu Rev Plant Biol. 2012; 63:131-52. DOI: 10.1146/annurev-arplant-042811-105522. View

17.

Vert G, Grotz N, Dedaldechamp F, Gaymard F, Guerinot M, Briat J . IRT1, an Arabidopsis transporter essential for iron uptake from the soil and for plant growth. Plant Cell. 2002; 14(6):1223-33. PMC: 150776. DOI: 10.1105/tpc.001388. View

18.

Yuan Y, Zhang J, Wang D, Ling H . AtbHLH29 of Arabidopsis thaliana is a functional ortholog of tomato FER involved in controlling iron acquisition in strategy I plants. Cell Res. 2005; 15(8):613-21. DOI: 10.1038/sj.cr.7290331. View

19.

Zhang J, Liu B, Li M, Feng D, Jin H, Wang P . The bHLH transcription factor bHLH104 interacts with IAA-LEUCINE RESISTANT3 and modulates iron homeostasis in Arabidopsis. Plant Cell. 2015; 27(3):787-805. PMC: 4558652. DOI: 10.1105/tpc.114.132704. View

20.

Henriques R, Jasik J, Klein M, Martinoia E, Feller U, Schell J . Knock-out of Arabidopsis metal transporter gene IRT1 results in iron deficiency accompanied by cell differentiation defects. Plant Mol Biol. 2002; 50(4-5):587-97. DOI: 10.1023/a:1019942200164. View