Elicitation of Differential Responses in the Root-Knot Nematode <i>Meloidogyne incognita</i> to Tomato Root Exudate Cytokinin, Flavonoids, and Alkaloids

Kirwa, Hillary; Murungi, Lucy Kananu; Beck, John J.; Torto, Baldwyn

doi:10.1021/acs.jafc.8b05101

Cited by 72 publications

(74 citation statements)

References 53 publications

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“…It's a reasonable deduction that concentrations of DHA used in this study reflect the concentration of DHA in wheat root exudates. It was found that like other attractants for nematodes reported [16,41], the response of H. avenae to DHA was concentration-dependent, because attraction levels of H. avenae to DHA with concentrations of 0.1 mg/L, 0.5 mg/L and 1.0 mg/L were different. Whether DHA plays roles in the orientations of plant for other nematodes remains unknown.…”

Section: Plos Onementioning

confidence: 85%

Dihydroxyacetone of wheat root exudates serves as an attractant for Heterodera avenae

Wang

Abdelnabby

et al. 2020

PLoS ONE

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Heterodera avenae, as an obligate endoparasite, causes severe yield loss in wheat (Triticum aestivum). Investigation on the mechanisms how H. avenae perceives wheat roots is limited. Here, the attractiveness of root exudates from eight plant genotypes to H. avenae were evaluated on agar plates. Results showed that the attraction of H. avenae to the root exudates from the non-host Brachypodium distachyon variety Bd21-3 was the highest, approximately 50 infective second-stage juveniles (J2s) per plate, followed by that from three H. avenae-susceptible wheat varieties, Zhengmai9023, Yanmai84 and Xiangmai25, as well as the resistant one of Xinyuan958, whereas the lowest attractive activity was observed in the two H. avenae-resistant wheat varieties, Xianmai20 (approximately 12 J2s/ plate) and Liangxing66 (approximately 11 J2s/plate). Then Bd21-3, Zhengmai9023 and Heng4399 were selected for further assays as their different attractiveness and resistance to H. avenae, and attractants for H. avenae in their root exudates were characterized to be heat-labile and low-molecular compounds (LM) by behavioral bioassay. Based on these properties of the attractants, a principle of identifying attractants for H. avenae was set up. Then LM of six root exudates from the three plants with and without heating were separated and analyzed by HPLC-MS. Finally, dihydroxyacetone (DHA), methylprednisolone succinate, embelin and diethylpropionin in the root exudates were identified to be putative attractants for H. avenae according to the principle, and the attraction of DHA to H. avenae was validated by behavioral bioassay on agar. Our study enhances the recognition to the orientation mechanism of H. avenae towards wheat roots.

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Section: Plos Onementioning

confidence: 85%

Dihydroxyacetone of wheat root exudates serves as an attractant for Heterodera avenae

Wang

Abdelnabby

et al. 2020

PLoS ONE

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“…With this perspective, it is interesting that repellent compounds have been identified in economically important host plants, where root knot nematodes are particularly problematic, e.g. tomato plants (Yang et al, 2016;Kirwa et al, 2018). In horticultural production, grafting is becoming a common alternative to lengthy breeding for pathogen resistance.…”

Section: Application Of Root Metabolites In Nematode Management-challmentioning

confidence: 99%

Impacts of Root Metabolites on Soil Nematodes

2020

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Plant parasitic nematodes cause significant crop damage globally. Currently, many nematicides have been banned or are being phased out in Europe and other parts of the world because of environmental and human health concerns. Therefore, we need to focus on sustainable and alternative methods of nematode control to protect crops. Plant roots contain and release a wide range of bioactive secondary metabolites, many of which are known defense compounds. Hence, profound understanding of the root mediated interactions between plants and plant parasitic nematodes may contribute to efficient control and management of pest nematodes. In this review, we have compiled literature that documents effects of root metabolites on plant parasitic nematodes. These chemical compounds act as either nematode attractants, repellents, hatching stimulants or inhibitors. We have summarized the few studies that describe how root metabolites regulate the expression of nematode genes. As non-herbivorous nematodes contribute to decomposition, nutrient mineralization, microbial community structuring and control of herbivorous insect larvae, we also review the impact of plant metabolites on these nontarget organisms.1 study on effect of both plant and specific metabolites detected in root exudates of the plant, 2 study on effect of plant, 3 study on effect of synthetic compound on nematodes, NA indicate not applicable.

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“…In vitro experiments have shown that several common flavonoids show (limited) anti-nematode activity: kaempferol is inhibitory to the hatching of R. similis eggs while kaempferol, quercetin, and myricetin are both repellent and somewhat nematistatic (but not nematicidal) to M. incognita juveniles (Wuyts et al, 2006b). The effect of flavonoids on nematode behavior, however, is complex: they can either attract or repel M. incognita juveniles depending on their molecular structure and concentration (Kirwa et al, 2018). Flavonoids have been most extensively studied in relation to plant-nematode interactions in the Fabaceae family, whose members produce various isoflavonoids and pterocarpans (phytoalexins derived from isoflavonoids via coupling of the isoflavonoid B ring and 4-one position) in response to infection.…”

Section: Flavonoidsmentioning

confidence: 99%