多环芳烃在冬小麦体内的吸收与转运及富集研究进展  

Research Advances in Uptake,Translocation and Accumulation of Polycyclic Aromatic Hydrocarbons in Winter Wheat

作　　者：石陶然[1,2] 田凯[1,2] 包环宇[1,2] 侯劭炜 刘雪平[3] 吴福勇[1,2] 

机构地区：[1]西北农林科技大学资源环境学院,陕西杨凌712100 [2]农业部西北植物营养与农业环境重点实验室,陕西杨凌712100 [3]河南城建学院市政与环境工程学院,河南平顶山467036

出　　处：《环境科学研究》2017年第9期1398-1405,共8页Research of Environmental Sciences

基　　金：国家自然科学基金项目(41571456);河南省高校科技创新人才支持计划项目(14HASTIT048)

摘　　要：多年来以煤炭为主的能源消费结构和经济社会持续发展,导致我国PAHs(多环芳烃)排放量居高不下,直接造成土壤和大气PAHs严重污染.为了探明PAHs在冬小麦体内的积累过程和调控机制,在系统分析PAHs在冬小麦体内的吸收、转运和富集的基础上,重点阐述了冬小麦PAHs根系吸收和叶面吸收影响因素方面的最新研究进展.研究发现:(1)小麦根系对PAHs的吸收包括主动吸收和被动吸收两种方式,其中主动吸收是一个载体协助、消耗能量、PAHs与H+共运的过程;被动吸收除了在高等植物中普遍存在的简单扩散外,水-甘油通道也参与了该过程.(2)PAHs通过气态、颗粒态沉降到小麦叶面角质层或直接通过气孔进入叶片.(3)影响PAHs根系和叶面吸收的主要因素包括PAHs理化性质、植物生理状况、环境因素等.(4)小麦根系吸收的PAHs可以向地上部转运,并且与辛醇-水分配系数(KOW)、蒸腾速率、土壤中氮的形态和浓度有关.主要问题:(1)对于小麦叶片吸收的PAHs向基运输机理有待进一步研究.(2)农田生态系统中冬小麦往往遭受土壤及大气双重污染,根系吸收及叶面吸收分别对其体内积累PAHs的贡献尚不清楚.因此,需关注韧皮部、木质部在PAHs转运中所起的作用;利用同位素示踪、双光子激发显微镜等先进技术观察和跟踪PAHs如何进入小麦以及在小麦叶中的转移和分布,阐明PAHs叶面吸收的微观机理;注重大田试验研究,为揭示冬小麦对PAHs的吸收、积累及调控机理,同时也为有机污染地区生产安全农产品提供重要依据.Due to continuous economic and social development and the predominant use of coal in energy consumption, emissions of PAHs in China has maintained a high level for years, which has resulted in serious PAHs contamination in atmospheric and soil environments. To evaluate the processes and mechanisms contributing to accumulation and regulation of PAHs in wheat, based on systematic analysis of characteristics and mechanisms of uptake, translocation and accumulation of PAHs in wheat, the present work focused on the effects ofroot and foliar uptake of PAHs. Previous studies have found that wheat root uptake of PAHs mainly includes active and passive processes, of which active process is a carrier-mediated, energy- consuming and H ＋ -coupled symport process. Besides simple diffusion, which is especially prevalent for passive uptake in higher p lan ts , PAHs could enter into roots viaaquaglyceroporin. PAHs could enter into leaves by gas-phase and particle-phase deposition onto the waxy cuticle or via the stomata. Root and foliage uptake of PAHs are governed by the physicochemical properties of PAHs , plant species and environmental conditions. Acropetal translocation of PAHs by root is associated with K Ow, transpiration r a te , nitrogen form and concentration in soil. Current studies face some challenges. The mechanisms of PAHs translocating from leaves to root need further research. In addition, winter wheat always suffers from the double pollutions of soil and atmosphere under field conditions, and the role of root and foliar uptake of PAHs in the accumulation of PAHs in wheat has not been developed yet. Therefore, more efforts should be devoted to illustrating the effects of phloem and xylem in translocation of PAHs, using powerful techniques such as isotope trace and two- photon excitation microscopy to visualize and track how such compounds enter, move and distribute within wheat foliage, providing insight into PAHs foliar uptake. Paying more attention to field

关 键 词：多环芳烃 小麦 根系吸收 叶面吸收 转运机理 

分 类 号：X56[环境科学与工程—环境工程]