OsFWL3调控水稻金属离子转运和积累的研究

Study on the Involvement of OsFWL3 in the Regulation of Metal Ion Transport and Accumulation in Rice

【目的】FWL(Fruit Weight2.2-Like)基因是细胞增殖的负调控因子,不仅调控植物器官发生和大小,也参与调控植株金属离子转运积累及信号转导,解析OsFWL3功能,有助于揭示作物体内微量金属元素转运机制,为减少重金属积累、改善作物品质提供理论支持。【方法】通过生物信息学方法,分析OsFWLs家族基因概况、基因组结构及系统进化树,并预测OsFWL3的时空表达分析。利用CRISPR/Cas9基因编辑技术,获得2个Osfwl3敲除株系,在苗期和灌浆期进行ZnSO4处理,分析处理后的幼苗和籽粒表型,测定Zn等金属元素含量变化,探究OsFWL3对Zn等金属离子转运和积累的影响。【结果】OsFWLs家族基因功能存在一定程度的相似性。OsFWL3在花药和圆锥花序中高表达,暗示其与水稻生殖发育密切相关,突变体Osfwl3的一级枝梗数显著增多,其种子在长度、厚度和百粒重方面显著大于WT。同时,OsFWL3影响水稻幼苗和籽粒中Zn等金属离子的含量和分布,OsFWL3缺失影响Zn、Cd、Mn从植株地下部向地上部、穗下部向穗中部以及稃壳向糙米的竞争性转运。【结论】OsFWL3影响水稻籽粒及植株中Zn等金属元素的积累和转运,对水稻植株生长发育和籽粒大小均起重要调控作用。

【Objective】FWL(Fruit Weight2.2-Like)gene is a negative regulator of cell proliferation,which not only regulates plant organogenesis and organ size,but also participates in the regulation of metal ion transport accumulation and signal transduction.Analyzing of the function of OsFWL3 gene is helpful to reveal the transport mechanism of trace metal elements in crops.It provides theoretical support for reducing heavy metal accumulation and improving crop quality.【Method】The gene information,genome structure and phylogenetic tree of OsFWLs family were analyzed by bioinformatics method,and the expression profile of OsFWL3 gene was predicted.Two OsFWL3 knockout lines were obtained using CRISPR/Cas9 gene editing technology.Then wild type and Osfwl3 mutants were treated with ZnSO4 at seedling stage and filling stage,respectively.The phenotypes of plants and grains after treatment were analyzed,and the content variation of metal elements such as Zn was determined to explore the effects of OsFWL3 on the transport and accumulation of metal ions and seed quality.【Result】The gene function of OsFWLs family is similar to some extent.OsFWL3 gene is highly expressed in anther and panicle,indicating that it is closely related to reproductive development of rice.The number of primary branches,grian length,grain thickness and 100-grain weight of Osfwl3 mutants are significantly larger than WT.OsFWL3 affects the content and distribution of Zn and other metal ions in rice seedlings and grains.The deletion of OsFWL3 gene affects the competitive transport of Zn,Cd and Mn from underground to above-ground,lower grain to central grain and husk to brown rice.【Conclusion】OsFWL3 gene affects the distribution of Zn and other metal ions in rice grains and plants,and it plays an important role in regulating the growth and development of rice plants and grain size.