Istituto di Biologia e Patologia Molecolari, Consiglio Nazionale delle Ricerche, Sapienza Università di Roma, 00185, Rome, Italy; Dipartimento di Biologia e Biotecnologie, Sapienza Università di Roma, 00185, Rome, Italy.
Dipartimento di Ingegneria Chimica Materiali Ambiente, La Sapienza - University of Roma, Via Eudossiana, 18, 00184, Rome, Italy.
Environ Pollut. 2022 Sep 15;309:119773. doi: 10.1016/j.envpol.2022.119773. Epub 2022 Jul 13.
In this work, arsenic (As) accumulation and distribution over time in Pteris vittata young fronds from adult plants and in whole plantlets, grown on a highly contaminated As-soil, was determined by μ-XRF. A linear increase in As content up to 60 days was found in young fronds at different times, and a progressive distribution from the apex to the base of the fronds was observed. In whole plantlets, As signal was detectable from 9 to 20 days in the apex of a few fronds and fiddleheads. Later, up to 60 days, As was localized in all fronds, in the rhizome and in basal part of the roots. The dynamics of expression of As-related genes revealed a good correlation between As content and the level of the As (III)-antiporter PvACR3 transcript in plantlets roots and fronds and in young fronds. Moreover, the transcription of As (V)-related gametophytic genes PvGAPC1, PvOCT4 increases over time during As accumulation while PvGSTF1 is expressed only in roots. Here, we demonstrate the suitability of the μ-XRF technique to monitor As accumulation, which allowed us to propose that As is initially directly transported to fiddleheads and apex of fronds, is later distributed to the whole fronds and simultaneously accumulated in the rhizome and roots. We also provide indications on the expression of candidate genes possibly involved in As (hyper)accumulation.
在这项工作中，通过微束 X 射线荧光（μ-XRF）技术测定了成年植株的凤尾蕨幼叶和整个苗在高砷污染土壤上生长过程中砷的积累和分布随时间的变化。结果发现，幼叶在不同时间的砷含量呈线性增加，直到 60 天；砷从叶梢向叶基逐渐分布。在整个苗中，从叶梢和幼叶的几枚叶片的顶端到 9-20 天可检测到砷信号。之后，直到 60 天，砷在所有叶片、根茎和根的基部都有分布。砷相关基因的表达动力学表明，苗的根和叶以及幼叶中的砷含量与砷（III）-转运蛋白 PvACR3 转录本水平之间存在良好的相关性。此外，随着砷的积累，砷（V）相关配子体基因 PvGAPC1、PvOCT4 的转录水平也随之增加，而 PvGSTF1 仅在根中表达。本研究表明，μ-XRF 技术可用于监测砷的积累，这使我们能够提出，砷最初直接运输到幼叶和叶梢，随后分布到整个叶片，并同时在根茎和根中积累。我们还提供了可能参与砷（超）积累的候选基因表达的相关信息。
