Restriction of iron loading into developing seeds by a YABBY transcription factor safeguards successful reproduction in Arabidopsis  

作　　者：Li Sun Yun Qi Wei Kang Hao Wu Jing Ying Yan Jie Na Xu Yun Rong Wu Gui Xin Li Ji Ming Xu Nicholas P.Harberd Zhong Jie Ding Shao Jian Zheng 

机构地区：[1]State Key Laboratory of Plant Physiology and Biochemistry,College of Life Sciences,Zhejiang University,Hangzhou 310058,China [2]Agricultural Experimental Station,Zhejiang University,Hangzhou 310058,China [3]College of Agronomy and Biotechnology,Zhejiang University,Hangzhou 310058,China [4]Department of Plant Science,University of Oxford,Oxford OX13RB,UK [5]Guangdong Laboratory for Lingnan Modern Agriculture,College of Natural Resources and Environment,South China Agricultural University,Guangzhou 510642

出　　处：《Molecular Plant》2021年第10期1624-1639,共16页分子植物（英文版）

基　　金：This work was supported by the Ministry of Science and Technology of the People's Republic of China(grant no.2016YFD0100704);the Natural Science Foundation of Zhejiang Province(Q19C020001);the Ministry of Education and Bureau of Foreign Experts of China(grant no.B14027);the Fundamental Research Funds for the Central Universities.

摘　　要：Iron(Fe)storage in plant seeds is not only necessary for seedling establishment following germination but is also a major source of dietary Fe for humans and other animals.Accumulation of Fe in seeds is known to be low during early seed development.However,the underlying mechanism and biological significance remain elusive.Here,we show that reduced expression of Arabidopsis YABBY transcription factor INNER NO OUTER(INO)increases embryonic Fe accumulation,while transgenic overexpression of INO results in the opposite effect.INO is highly expressed during early seed development,and decreased INO expression increases the expression of NATURAL RESISTANCE-ASSOCIATED MACROPHAGE PROTEIN 1(NRAMP1),which encodes a transporter that contributes to seed Fe loading.The relatively high embryonic Fe accumulation conferred by decreased INO expression is rescued by the nramp1 loss-of-function mutation.We further demonstrated that INO represses NRAMP1 expression by binding to NRAMP1-specific promoter region.Interestingly,we found that excessive Fe loading into developing seeds of ino mutants results in greater oxidative damage,leading to increased cell death and seed abortion,a phenotype that can be rescued by the nramp1 mutation.Taken together,these results indicate that INO plays an important role in safeguarding reproduction by reducing Fe loading into developing seeds by repressing NRAMP1 expression.

关 键 词：IRON seed EMBRYO toxicity transcription factor ARABIDOPSIS 

分 类 号：Q943.2[生物学—植物学]