|
Four IVa bHLH Transcription Factors Are Novel Interactors of FIT and Mediate JA Inhibition of Iron Uptake in Arabidopsis
Yan Cui, Chun-Lin Chen, Man Cui, Wen-Juan Zhou, Hui-Lan Wu, Hong-Qing Ling
Molecular Plant
Abstract
Plants have evolved sophisticated genetic networks to regulate iron (Fe) homeostasis for their survival. Several classes of plant hormones including Jasmonic acid (JA) have been shown to be involved in regulating the expression of iron uptake and/or deficiency-responsive genes in plants. However, the molecular mechanisms by which JA regulates iron uptake remain unclear. In this study, we found that JA negatively modulated iron uptake by downregulating the expression of FIT (bHLH29), bHLH38, bHLH39, bHLH100, and bHLH101 and promoting the degradation of FIT protein, a key regulator of iron uptake in Arabidopsis. We further demonstrated that the subgroup IVa bHLH proteins, bHLH18, bHLH19, bHLH20, and bHLH25, are novel interactors of FIT, which promote JA-induced FIT protein degradation. They function redundantly to antagonize the Ib bHLH proteins (such as bHLH38) activity in regulating FIT protein stability under iron deficiency. The four IVa bHLH genes are primarily expressed in roots, and are inducible by JA treatment. Moreover, we found that MYC2 and JAR1, two critical components of the JA signaling pathway, play critical roles in mediating JA suppression of the expression of FIT and Ib bHLH genes, whereas they differentially modulate the expression of bHLH18, bHLH19, bHLH20, and bHLH25 to regulate FIT accumulation under iron deficiency. Taken together, these results indicate that by transcriptionally regulating the expression of different sets of bHLH genes JA signaling promotes FIT degradation, resulting in reduced expression of iron uptake genes, IRT1 and FRO2, and increased sensitivity to iron deficiency. Our data suggest that there is a multilayered inhibition of iron deficiency response in the presence JA in Arabidopsis.
|
论文编号: |
DOI:10.1016/j.molp.2018.06.005 |
论文题目: |
Four IVa bHLH Transcription Factors Are Novel Interactors of FIT and Mediate JA Inhibition of Iron Uptake in Arabidopsis |
英文论文题目: |
Four IVa bHLH Transcription Factors Are Novel Interactors of FIT and Mediate JA Inhibition of Iron Uptake in Arabidopsis |
第一作者: |
Yan Cui, Chun-Lin Chen, Man Cui, Wen-Juan Zhou, Hui-Lan Wu, Hong-Qing Ling |
英文第一作者: |
Yan Cui, Chun-Lin Chen, Man Cui, Wen-Juan Zhou, Hui-Lan Wu, Hong-Qing Ling |
联系作者: |
|
英文联系作者: |
|
外单位作者单位: |
|
英文外单位作者单位: |
|
发表年度: |
2018-07-02 |
卷: |
|
期: |
|
页码: |
|
摘要: |
Plants have evolved sophisticated genetic networks to regulate iron (Fe) homeostasis for their survival. Several classes of plant hormones including Jasmonic acid (JA) have been shown to be involved in regulating the expression of iron uptake and/or deficiency-responsive genes in plants. However, the molecular mechanisms by which JA regulates iron uptake remain unclear. In this study, we found that JA negatively modulated iron uptake by downregulating the expression of FIT (bHLH29), bHLH38, bHLH39, bHLH100, and bHLH101 and promoting the degradation of FIT protein, a key regulator of iron uptake in Arabidopsis. We further demonstrated that the subgroup IVa bHLH proteins, bHLH18, bHLH19, bHLH20, and bHLH25, are novel interactors of FIT, which promote JA-induced FIT protein degradation. They function redundantly to antagonize the Ib bHLH proteins (such as bHLH38) activity in regulating FIT protein stability under iron deficiency. The four IVa bHLH genes are primarily expressed in roots, and are inducible by JA treatment. Moreover, we found that MYC2 and JAR1, two critical components of the JA signaling pathway, play critical roles in mediating JA suppression of the expression of FIT and Ib bHLH genes, whereas they differentially modulate the expression of bHLH18, bHLH19, bHLH20, and bHLH25 to regulate FIT accumulation under iron deficiency. Taken together, these results indicate that by transcriptionally regulating the expression of different sets of bHLH genes JA signaling promotes FIT degradation, resulting in reduced expression of iron uptake genes, IRT1 and FRO2, and increased sensitivity to iron deficiency. Our data suggest that there is a multilayered inhibition of iron deficiency response in the presence JA in Arabidopsis. |
英文摘要: |
Plants have evolved sophisticated genetic networks to regulate iron (Fe) homeostasis for their survival. Several classes of plant hormones including Jasmonic acid (JA) have been shown to be involved in regulating the expression of iron uptake and/or deficiency-responsive genes in plants. However, the molecular mechanisms by which JA regulates iron uptake remain unclear. In this study, we found that JA negatively modulated iron uptake by downregulating the expression of FIT (bHLH29), bHLH38, bHLH39, bHLH100, and bHLH101 and promoting the degradation of FIT protein, a key regulator of iron uptake in Arabidopsis. We further demonstrated that the subgroup IVa bHLH proteins, bHLH18, bHLH19, bHLH20, and bHLH25, are novel interactors of FIT, which promote JA-induced FIT protein degradation. They function redundantly to antagonize the Ib bHLH proteins (such as bHLH38) activity in regulating FIT protein stability under iron deficiency. The four IVa bHLH genes are primarily expressed in roots, and are inducible by JA treatment. Moreover, we found that MYC2 and JAR1, two critical components of the JA signaling pathway, play critical roles in mediating JA suppression of the expression of FIT and Ib bHLH genes, whereas they differentially modulate the expression of bHLH18, bHLH19, bHLH20, and bHLH25 to regulate FIT accumulation under iron deficiency. Taken together, these results indicate that by transcriptionally regulating the expression of different sets of bHLH genes JA signaling promotes FIT degradation, resulting in reduced expression of iron uptake genes, IRT1 and FRO2, and increased sensitivity to iron deficiency. Our data suggest that there is a multilayered inhibition of iron deficiency response in the presence JA in Arabidopsis. |
刊物名称: |
Molecular Plant |
英文刊物名称: |
Molecular Plant |
论文全文: |
|
英文论文全文: |
|
全文链接: |
|
其它备注: |
Yan Cui, Chun-Lin Chen, Man Cui, Wen-Juan Zhou, Hui-Lan Wu, Hong-Qing Ling. Four IVa bHLH Transcription Factors Are Novel Interactors of FIT and Mediate JA Inhibition of Iron Uptake in Arabidopsis. Molecular Plant. DOI:10.1016/j.molp.2018.06.005 |
英文其它备注: |
|
学科: |
|
英文学科: |
|
影响因子: |
|
第一作者所在部门: |
|
英文第一作者所在部门: |
|
论文出处: |
|
英文论文出处: |
|
论文类别: |
|
英文论文类别: |
|
参与作者: |
|
英文参与作者: |
|
|