Tiong Jingwen, McDonald Glenn, Genc Yusuf, Shirley Neil, Langridge Peter, Huang Chun Y
Australian Centre for Plant Functional Genomics, School of Agriculture Food and Wine, the University of Adelaide, PMB1, Glen Osmond, SA, 5064, Australia.
School of Agriculture, Food and Wine, the University of Adelaide, Glen Osmond, SA, 5064, Australia.
New Phytol. 2015 Sep;207(4):1097-109. doi: 10.1111/nph.13413. Epub 2015 Apr 22.
Low zinc (Zn) in soils reduces yield and grain Zn content. Regulation of ZRT/IRT-like protein (ZIP) family genes is a major mechanism in plant adaptation to low and fluctuating Zn in soil. Although several Zn deficiency-inducible ZIP genes are identified in cereals, there has been no systematic study on the association of Zn deficiency-induced uptake and root-to-shoot translocation with expression of ZIP family genes. We measured Zn deficiency-induced uptake and root-to-shoot translocation of Zn in barley (Hordeum vulgare) plants by resupplying 0.5 μM Zn, and quantified the transcripts of thirteen HvZIP genes. Subcellular localization and tissue-specific expression were also determined for Zn deficiency-inducible HvZIP genes. Zn deficiency enhanced the capacity of uptake and root-to-shoot translocation of Zn, and sustained the enhanced capacity for 6 d after Zn resupply. Six HvZIP genes were highly induced in roots of Zn-deficient plants, and their proteins were localized in the plasma membrane. Tissue-specific expression in roots supports their roles in uptake and root-to-shoot translocation of Zn under low Zn conditions. Our results provide a comprehensive view on the physiological roles of ZIP genes in plant adaptation to low and fluctuating Zn in soil, and pave the way for development of new strategies to improve Zn-deficiency tolerance and biofortification in cereals.
土壤中低锌（Zn）会降低产量和籽粒锌含量。ZRT/IRT类蛋白（ZIP）家族基因的调控是植物适应土壤中低锌和波动锌的主要机制。尽管在谷类作物中已鉴定出几个锌缺乏诱导型ZIP基因，但尚未对锌缺乏诱导的锌吸收及从根到地上部的转运与ZIP家族基因表达之间的关联进行系统研究。我们通过重新供应0.5μM锌来测定锌缺乏诱导的大麦（Hordeum vulgare）植株对锌的吸收及从根到地上部的转运，并对13个HvZIP基因的转录本进行定量分析。还确定了锌缺乏诱导型HvZIP基因的亚细胞定位和组织特异性表达。锌缺乏增强了植株对锌的吸收及从根到地上部的转运能力，并且在重新供应锌后6天内维持了这种增强的能力。6个HvZIP基因在缺锌植株的根中被高度诱导，其蛋白定位于质膜。根中的组织特异性表达支持了它们在低锌条件下对锌的吸收及从根到地上部转运中的作用。我们的结果全面阐述了ZIP基因在植物适应土壤中低锌和波动锌过程中的生理作用，为开发提高谷类作物耐锌缺乏及生物强化的新策略铺平了道路。
