果树作物叶片对锌的吸收、运输与再利用机制的原位解析

Foliar fertilization is an important tool to achieve optimal profitability in modern agricultural production, especially for trace elements such as Zn. Currently our knowledge of the physical and biological factors that determine the efficacy of a given application is inadequate. Uncertainty exists as to the site of entry of nutrients into the leaf, the mechanism and rate of translocation out of the leaf, the chemical interactions that occur within the leaf. This project will utilize new methodology (Nano-XRF, LA-ICPMS), combined with stable isotope tracing and HPF, to investigate the mechanisms involved in the uptake and translocation of foliar Zn by using typical Zn deficiency sensitive Apple and pistachio trees. Mainly, the project will be focused on: 1) the penetration processes of Zn from leaf surface to the leaf body; 2) high spatial quantification (cellular and subcellular) of elemental distribution within the leaf tissues; 3) elemental composition and complexation in phloem and new growing tissues, with the aim of 1) increasing our understanding of the processes that govern the localization and transport of foliar applied nutrients 2) developing methods for screening new materials. This project activity may facilitate the improvement of foliar Zn with a higher efficiency and low cost.

叶面施肥是有效矫正微量元素缺乏症的主导手段，但叶面养分吸收机理研究滞后，严重制约叶面微肥的开发与应用。本项目针对石灰性土壤普遍缺锌的生产实际，重点围绕果树作物叶面施锌吸收难、转运慢的关键问题，在前期突破植物体内锌的原位示踪与定位技术瓶颈的基础上，以苹果、开心果等缺锌敏感的代表性高价值果树作物为对象，综合运用Nano-XRF、LA-ICPMS、μ-XAS、同位素示踪等技术，研究叶片表面特性对锌吸收的影响及其机制；分析锌在叶片中的动态分布规律，从细胞和亚细胞水平上对锌进行二维与三维图像定位，剖析锌进入叶细胞的主要途径及其储存位点；研究锌在韧皮部再转运过程中的赋存形态与微区分布特征，原位解析植物体内锌的再转运规律及其影响因素，旨在构建并优化叶面锌吸收的快速原位评价技术平台，揭示经济作物叶片对锌的吸收、运输与再利用机制及其调控技术，为进一步全面揭示叶面锌肥的作用机理、提高肥料利用率提供理论依据

叶面施肥是有效矫正微量元素缺乏症的主导手段，但叶面养分吸收机理研究滞后，严重制约叶面微肥的开发与应用。本项目针对石灰性土壤普遍缺锌的生产实际，重点围绕果树作物叶面施锌吸收难、转运慢的关键问题，以苹果、开心果、小麦、柑橘等缺锌敏感的代表性高价值经济作物为对象，综合运用Nano-XRF、μ-XAS、同位素示踪等技术，从组织、细胞到亚细胞水平上对植物体内锌进行定位，剖析锌在不同品种经济作物中的吸收、转运与再利用规律，并进一步明确了叶片表面特性对锌吸收的影响及其机制，分析锌在叶片中的动态分布特征。本研究揭示了不同经济作物对锌的养分需求特征及叶片对锌的吸收运输机制，为进一步全面揭示叶面锌肥的作用机理、提高肥料利用率提供理论依据。