Title

Molecular genetic basis of the FRO6-mediated regulatory network underlying excess iron-induced leaf senescence

Alternative Title

과잉 철 유도 잎 노화의 FRO6 매개 조절 네트워크에 대한 분자유전학적 연구

DGIST Authors

Hyunsu Park ; Hye Ryun Woo ; Sung Bae Lee

Advisor

우혜련

Co-Advisor(s)

Sung Bae Lee

Issued Date

2026

Awarded Date

2026-08-01

Type

Thesis

Description

leaf senescence, flowering time, reproductive development, Fe, Fe homeostasis, jasmonic acid signaling pathway

Table Of Contents

I. Background introduction 1
1.1 Plant senescence 1
1.2 Nutrient regulation 4
1.3 Nutrient regulation in plant senescence 6
1.4 Plant micronutrients 7
1.5 Iron regulation 9
1.6 Iron homeostasis and its regulation 14
1.7 Ferric Reduction Oxidase (FRO) family 16
1.8 Research goal and Specific aims 17
II. FERRIC REDUCTION OXIDASE 6 (FRO6) regulates excess Fe-induced leaf senescence in Arabidopsis 18
2.1 Background 18
2.2 Results 20
2.2.1 Age-dependent increase in Fe levels during leaf senescence 20
2.2.2 Fe accumulation induces premature leaf senescence in Arabidopsis 25
2.2.3 FRO6 is differentially expressed in response to Fe treatment and during leaf senescence in Arabidopsis 28
2.2.4 FRO6 functions as a negative regulator of age-dependent leaf senescence in Arabidopsis 32
2.2.5 FRO6 modulates leaf senescence across a wide range of Fe availability through its catalytic activity 40
2.2.6 Dynamic expression of Fe–S cluster assembly components and Fe transporters during leaf senescence 46
2.3 Discussion 51
III. Genetic and molecular mechanisms of the FRO6-associated regulatory network in leaf senescence 54
3.1 Background 54
3.2 Results 56
3.2.1 Transcriptome analysis reveals FRO6 regulation of autophagy and JA signaling pathways in excess Fe-induced leaf senescence 56
3.2.2 MYC2 acts downstream of FRO6 in leaf senescence 61
3.2.3 SVP directly activates FRO6 transcription 63
3.2.4 SVP regulates floral transition and leaf senescence by acting upstream of FRO6 66
3.3 Discussion 73
IV. Appendix 76
4.1 Agronomic implications of FRO6 76
4.1.1 Introduction 76
4.1.2 Background 77
4.1.3 Results 78
4.1.4 Discussion 86
V. Materials & Methods in this thesis 89
5.1 Plant materials and growth conditions 89
5.2 Determination of Fe content 90
5.3 RNA extraction and quantitative gene expression analysis 91
5.4 Leaf senescence assays 91
5.5 mRNA-sequencing (mRNA-seq) and differential expression analysis 92
5.6 Comparative transcriptomic analyses 93
5.7 Histochemical analysis 94
5.8 Analysis of DNA affinity purification sequencing (DAP-seq) data 94
5.9 Transient luciferase assay 95
5.10 Chromatin immunoprecipitation (ChIP) assay 95
5.11 Yeast two-hybrid screening assay 96
5.12 Co-immunoprecipitation (Co-IP) Assay 97
5.13 Bimolecular fluorescence complementation (BiFC) Assay 98
5.14 Flowering time measurement 98
5.15 Seed phenotype analysis 98
5.16 Statistical analysis 99
5.17 Drawing schematic diagram 99
VI. References 104

URI

https://scholar.dgist.ac.kr/handle/20.500.11750/60727
http://dgist.dcollection.net/common/orgView/200001006631

DOI

10.22677/THESIS.200001006631

Degree

Doctor

Department

Department of New Biology

Publisher

DGIST

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