Two bHLH Transcription Factors, bHLH34 and bHLH104, Regulate Iron Homeostasis in Arabidopsis thaliana

bHLH transcription factor bHLH115 regulates iron homeostasis in Arabidopsis thaliana

“…Our previous work confirmed that overexpression of bHLH101 only rescued Fe-deficiency induction of IRT1 and FRO2 , but not of MYB10 and MYB72, in the bhlh34 bhlh104 double-mutant (Li et al , 2016). This suggests that unknown target genes of bHLH34 and bHLH104 have yet to be identified.…”

“…T-DNA insertion lines for bhlhl115-1 (WiscDsLox384C11) and bhlh115-2 (WiscDsLox384D9) were sourced from the Arabidopsis Biological Resource Center (ABRC; ) and were confirmed using PCR with a T-DNA primer (p745) and gene-specific primers (see Supplementary Table S1 at JXB online). The bhlh34 , bhlh104 , bhlh105 , and bts-1 mutants have been described previously (Long et al , 2010; Li et al , 2016). The homozygous mutants were crossed with each other to generate double- and triple-mutants.…”

“…GAD-bHLH34, GAD-bHLH104, and GAD-bHLH105 have been described previously (Li et al , 2016). The combination of pGBKT7-53 and pGADT7-T was used as a positive control and the combination of pGBKT7-Lam and pGADT7-T as a negative control.…”

Ubiquitination-Related MdBT Scaffold Proteins Target a bHLH Transcription Factor for Iron Homeostasis

“…Its Arabidopsis ortholog FER-LIKE IRON DEFICIENCY-INDUCED TRANSCRIPTION FACTOR (FIT) controls iron uptake by directly regulating the expression of the FRO2 and IRT1 genes under Fe-deficient conditions (Colangelo and Guerinot, 2004;Yuan et al, 2005Yuan et al, , 2008. Meanwhile, several other bHLH TFs such as IAA-Leu Resistant 3 (ILR3, also called bHLH105), PYE, bHLH104, OsbHLH133, and CmbHLH1 regulate plant growth and development by mediating the activity of Fe-chelate reductase, the acidification of rhizospheres, and the transportation of iron under Fe-deficient conditions in Arabidopsis, rice (Oryza sativa), and chrysanthemum (Chrysanthemum morifolium; Li et al, 2016;Long et al, 2010;Selote et al, 2015;Wang et al, 2013;Zhang et al, 2015;Zhao et al, 2014). In rice, IRON-RELATED TRANSCRIPTION FACTOR 2 (IRO2) is a homolog of bHLH38 and bHLH39.…”

Iron-Nicotianamine Transporters Are Required for Proper Long Distance Iron Signaling

“…In Arabidopsis, the genes most directly responsible for iron uptake are the Fe(II) transporter IRT1 (Eide et al, 1996;Henriques et al, 2002;Varotto et al, 2002;Vert et al, 2002) and the ferric chelate reductase FRO2 (Robinson et al, 1999;Connolly et al, 2003). Both these genes are strongly up-regulated by iron deficiency, and regulatory proteins governing the expression of these genes have been the subject of intense investigation (Colangelo and Guerinot, 2004;Jakoby et al, 2004;Yuan et al, 2005Yuan et al, , 2008Bauer et al, 2007;Wang et al, 2007;Long et al, 2010;Selote et al, 2015;Li et al, 2016;Mai et al, 2016). An additional component of iron uptake in nongraminaceous plants is the discovery that iron deficiency induces the secretion of phenolics and flavins (Rodríguez-Celma et al, 2013), later better defined as coumarins (Schmid et al, 2014) that are secreted by the ABCG37/PDR9 transporter (Fourcroy et al, 2014).…”