化感物质对植物根系形态属性影响的meta分析

植物化感作用是通过释放到环境中的化感物质直接或间接影响受试植物生长而实现的。化感物质主要作用于根系,所以植物根系属性是化感作用研究的重要指标之一。目前,关于受试植物形态属性对外源化感物质的响应模式尚缺乏整体的认识。为此,本文对61篇有关纯化感物质(包括酚类、萜类和含氮化合物等)对植物根系形态属性(尤其是根长)影响的文献进行整合分析。结果发现: 整体上化感物质处理显著抑制根长,而对根生物量、根表面积和根体积等形态属性影响较小;酚类对根长的抑制效应最大,且化感物质对草本植物根长的抑制率高于木本、作物和其他植物;酚类与根长抑制效应呈显著的线性相关。进一步量化了4种典型酚酸——阿魏酸、对羟基苯甲酸、香草酸和肉桂酸的浓度-效应关系,证实了黄酮对受试植物根长的抑制效应显著高于酚酸类化感物质。受试植物根系属性对化感物质的响应主要受化感物质类型和添加浓度、植物种类与培养条件等多因素影响,建议未来研究在土壤环境条件下综合评价化感物质对受试植物根系形态和生理属性以及根系构型等参数的影响机制。

Effects of alleolchemicals on morphological traits of roots: A meta-analysis

Allelopathy is a plant-plant interaction mediated by the allelochemicals, which directly or indirectly influence plant growth. As the major part in response to allelochemicals, root morphological traits play an important role in allelopathy research. The global pattern of effects of exogenous allelochemicals on root morphology is not well known. We carried out a meta-analysis based on 61 studies to assess the effects of allelochemicals, including phenols, terpenoids, nitrogen-containing allelochemicals, on root morphology, especially on root length. We found that the allelochemicals significantly inhibited root length, but had little effect on root biomass, root surface area, and root volume. Phenols exhibited the most inhibitory effects on root length, while the allelochemicals had more inhibitory effect on root length of herbs than woody species as well as crops and other species. There was a linear relationship between phenols concentrations and their effect size. We quantified the dose-effect relationship of four phenolic acids, ferulic acid, p-hydroxybenzoic acid, vanillic acid and cinnamic acid. The inhibitory effect of flavonoids on root length was significantly higher than that of phenolic acids. Together, these findings suggested that the responses of target plant root traits to allelochemicals depended on allelochemicals type and dose, species identity, and culture conditions. Future studies need to decipher the mechanism underlying the allelochemicals on root traits of morphology, physiology and architecture under soil environment.