Metabolic responses of willow (Salix purpurea L.) leaves to mycorrhization as revealed by mass spectrometry and 1H NMR spectroscopy metabolite profiling

Abstract

The root system of most terrestrial plants form symbiotic interfaces with arbuscular mycorrhizal fungi (AMF), which are important for nutrient cycling and ecosystem sustainability. The elucidation of the undergoing changes in plants' metabolism during symbiosis is essential for understanding nutrient acquisition and for alleviation of soil stresses caused by environmental cues. Within this context, we have undertaken the task of recording the fluctuation of willow (Salix purpurea L.) leaf metabolome in response to AMF inoculation. The development of an advanced metabolomics/bioinformatics protocol employing mass spectrometry (MS) and 1H NMR analyzers combined with the in-house-built metabolite library for willow (http://willowmetabolib.research.mcgill.ca/index.html) are key components of the research. Analyses revealed that AMF inoculation of willow causes up-regulation of various biosynthetic pathways, among others, those of flavonoid, isoflavonoid, phenylpropanoid, and the chlorophyll and porphyrin pathways, which have well-established roles in plant physiology and are related to resistance against environmental stresses. The recorded fluctuation in the willow leaf metabolism is very likely to provide AMF-inoculated willows with a significant advantage compared to non-inoculated ones when they are exposed to stresses such as, high levels of soil pollutants. The discovered biomarkers of willow response to AMF inoculation and corresponding pathways could be exploited in biomarker-assisted selection of willow cultivars with superior phytoremediation capacity or genetic engineering programs.

Enhanced Secondary- and Hormone Metabolism in Leaves of Arbuscular Mycorrhizal Medicago truncatula

“…5A; Table III). Similarly, an improvement of luteolin-7-O-glucoside was observed in shoots of mycorrhized willow (Salix purpurea; Aliferis et al, 2015).…”

Effect of Different Combinations of Phosphorus and Nitrogen Fertilization on Arbuscular Mycorrhizal Fungi and Aphids in Wheat

“…Moreover, AMF may enhance the resistance of plants to pest by changing the primary or secondary plant metabolites [18], which have strong antifeedant activity [19] and toxicity [20,21]. For example, a study on the leaf metabolome of willow (Salix purpurea L., Salicales: Salicaceae) showed that AMF cause up-regulation of the biosynthetic pathways of isoflavonoids, phenylpropanoids, and chlorophyll synthesis [22]. Other studies indicate that AMF increase the concentration of phenolics or flavonoids in the roots and shoots of plants, and reduce the abundance of legume pod borers (Maruca vitrata Fabricius, Lepidoptera: Pyralidae) [23] and pea aphids (Acyrthosiphon pisum Harris, Aphididae: Macrosiphini) in plants [24].…”

The effect of fungal-bacterial interaction on the phenolic profile of Pinus pinea L.

“…Bacteria may increase the absorption of organic phosphorus (Bashan et al 2013), and the fungus significantly increases the efficiency of plant in the use of phosphorus (Schweiger et al 2014;Araújo et al 2018). In a study by Aliferis et al (2015), the metabolites involved in the metabolism of amino acids were detected in lower amounts in mycorrhizal plants; according to the authors, there was a greater allocation of carbon to the roots where the mycorrhizal interaction occurs.…”