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SKB1/ PRMT 5‐mediated histone H 4 R 3 dimethylation of I b subgroup bHLH genes negatively regulates iron homeostasis in A rabidopsis thaliana
Author(s) -
Fan Huajie,
Zhang Zhaoliang,
Wang Ning,
Cui Yan,
Sun Hua,
Liu Yi,
Wu Huilan,
Zheng Shusong,
Bao Shilai,
Ling HongQing
Publication year - 2014
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1111/tpj.12380
Subject(s) - histone , chromatin immunoprecipitation , chromatin , arabidopsis , chemistry , context (archaeology) , microbiology and biotechnology , transcription factor , chromatin remodeling , biology , gene , histone h3 , mutant , biochemistry , gene expression , promoter , paleontology
Summary Histone modifications play critical roles in the perception of environmental cues by plants. Here, we report that S hk1 binding protein 1 ( SKB 1/ A t PRMT 5), which catalyzes the symmetric dimethylation of histone H 4 R 3 ( H 4 R 3sme2), is involved in iron homeostasis in Arabidopsis. The SKB1 lesion mutant exhibited higher iron accumulation in shoots and greater tolerance to iron deficiency than the wild type. The expression of SKB1 was not affected by iron, but the level of H4R3sme2 mediated by SKB 1 was related to iron status in plants. We showed by chromatin immunoprecipitation ( C h IP ) and genome‐wide C h IP ‐seq that SKB 1 associated with the chromatin of the I b subgroup bHLH genes ( AtbHLH38 , AtbHLH39 , AtbHLH100 and AtbHLH101 ), and symmetrically dimethylated histone H 4 R 3. The quantity of SKB 1 that associated with chromatin of the I b subgroup bHLH genes and the level of H 4 R 3sme2 corresponded to the iron status of plants (higher with increased iron supply and lower when iron was removed). We conclude that SKB 1‐mediated H 4 R 3sme2 regulates iron homeostasis in Arabidopsis in the context of increasing or decreasing expression of I b subgroup bHLH genes. Iron deficiency may cause an increase in the disassociation of SKB 1 from chromatin of the bHLH genes and a decrease in the level of H 4 R 3sme2, thereby elevating their transcription and enhancing iron uptake. Our findings provide new insight into the molecular mechanisms of iron homeostasis in strategy I plants.