Fuchs Benjamin, Laihonen Miika, Muola Anne, Saikkonen Kari, Dobrev Petre I, Vankova Radomira, Helander Marjo
Biodiversity Unit, University of Turku, Turku, Finland.
Laboratory of Hormonal Regulations in Plants, Institute of Experimental Botany of the Czech Academy of Sciences, Prague, Czechia.
Front Plant Sci. 2022 Jan 27;12:787958. doi: 10.3389/fpls.2021.787958. eCollection 2021.
Glyphosate is the most widely used herbicide with a yearly increase in global application. Recent studies report glyphosate residues from diverse habitats globally where the effect on non-target plants are still to be explored. Glyphosate disrupts the shikimate pathway which is the basis for several plant metabolites. The central role of phytohormones in regulating plant growth and responses to abiotic and biotic environment has been ignored in studies examining the effects of glyphosate residues on plant performance and trophic interactions. We studied interactive effects of glyphosate-based herbicide (GBH) residues and phosphate fertilizer in soil on the content of main phytohormones, their precursors and metabolites, as well as on plant performance and herbivore damage, in three plant species, oat (), potato (), and strawberry (). Plant hormonal responses to GBH residues were highly species-specific. Potato responded to GBH soil treatment with an increase in stress-related phytohormones abscisic acid (ABA), indole-3-acetic acid (IAA), and jasmonic acid (JA) but a decrease in cytokinin (CK) ribosides and cytokinin-O-glycosides. GBH residues in combination with phosphate in soil increased aboveground biomass of potato plants and the concentration of the auxin phenylacetic acid (PAA) but decreased phaseic acid and cytokinin ribosides (CKR) and O-glycosides. Chorismate-derived compounds [IAA, PAA and benzoic acid (BzA)] as well as herbivore damage decreased in oat, when growing in GBH-treated soil but concentrations of the cytokinin dihydrozeatin (DZ) and CKR increased. In strawberry plants, phosphate treatment was associated with an elevation of auxin (IAA) and the CK -zeatin (tZ), while decreasing concentrations of the auxin PAA and CK DZ was observed in the case of GBH treatment. Our results demonstrate that ubiquitous herbicide residues have multifaceted consequences by modulating the hormonal equilibrium of plants, which can have cascading effects on trophic interactions.
草甘膦是使用最广泛的除草剂，全球使用量逐年增加。最近的研究报告了全球不同栖息地的草甘膦残留情况，但其对非靶标植物的影响仍有待探索。草甘膦会破坏莽草酸途径，而莽草酸途径是多种植物代谢物的基础。在研究草甘膦残留对植物性能和营养相互作用的影响时，植物激素在调节植物生长以及对非生物和生物环境的反应中的核心作用被忽视了。我们研究了土壤中基于草甘膦的除草剂（GBH）残留和磷肥对三种植物（燕麦、马铃薯和草莓）中主要植物激素及其前体和代谢物的含量，以及对植物性能和食草动物损害的交互作用。植物对GBH残留的激素反应具有高度的物种特异性。马铃薯对GBH土壤处理的反应是，与胁迫相关的植物激素脱落酸（ABA）、吲哚-3-乙酸（IAA）和茉莉酸（JA）增加，但细胞分裂素（CK）核糖苷和细胞分裂素-O-糖苷减少。GBH残留与土壤中的磷酸盐结合，增加了马铃薯植株的地上生物量和生长素苯乙酸（PAA）的浓度，但降低了阶段酸和细胞分裂素核糖苷（CKR）以及O-糖苷。当燕麦在GBH处理的土壤中生长时，来自分支酸的化合物[IAA、PAA和苯甲酸（BzA）]以及食草动物的损害减少，但细胞分裂素二氢玉米素（DZ）和CKR的浓度增加。在草莓植株中，磷酸盐处理与生长素（IAA）和细胞分裂素玉米素（tZ）的升高有关，而在GBH处理的情况下，观察到生长素PAA和细胞分裂素DZ的浓度降低。我们的结果表明，无处不在的除草剂残留通过调节植物的激素平衡产生多方面的影响，这可能对营养相互作用产生连锁反应。
