Activity of the novel fungicide SYP-Z048 against plant pathogens

Abstract

In in vitro tests with 18 plant pathogens, the fungicide 3-[5-(4-chlorophenyl)-2,3-dimethyl-3-isoxazolidinyl] pyridine (SYP-Z048) was highly effective on inhibiting mycelial growth of various ascomycota and basidiomycota, with EC50 values ranging from 0.008 to 1.140 μg/ml. SYP-Z048 had much weaker activity against growth of oomycota with EC50 values > 100 μg/ml. In a second in vitro test with Monilinia fructicola isolates, SYP-Z048 inhibited mycelial growth (EC50 = 0.013 μg/ml), germ tube elongation (EC50 = 0.007 μg/ml), and sporulation but did not affect spore germination. In a detached pear fruit assay inoculated with M. fructicola isolates, SYP-Z048 showed protective and curative activity. Field tests indicated that SYP-Z048 was an efficacious fungicide for control of brown rot disease in two peach orchards. When applied to a single spot on a tomato leaflet in a compound leaf, SYP-Z048 suppressed the growth of Botrytis cinerea isolates on the rest 4 leaflets, indicating that the fungicide has systemic movement in plant tissues. These results indicate that SYP-Z048 has potential for management of brown rot causing by M. fructicola and other diseases caused by ascomycota and basidiomycota.

Heterologous expression of the Monilinia fructicola CYP51 (MfCYP51) gene in Pichia pastoris confirms the mode of action of the novel fungicide, SYP-Z048

“…It has also been found that SYP-Z048 provides highly effective control of the closely related species Monilinia fructicola (G. Winter) Honey, a ubiquitous pathogen that is the primary causal agent of brown rot in stone fruit (EPPO/CABI 1 ). The EC 50 value for SYP-Z048 in baseline populations of M. fructicola is 0.017 μg/ml (Chen et al, 2012 ), which is similar to the values for propiconazole (0.03 μg/ml) (Zehr et al, 1999 ) and tebuconazole (0.016 μg/ml) (Yoshimura et al, 2004 ), and field trials have indicated that SYP-Z048 effectively controls brown rot in peach orchards (Chen et al, 2014 ).…”

“…The novel isoxazolidine class fungicide SYP-Z048 (Liu et al, 2012 ), 3-[5-(4-chlorophenyl)-2,3-dimethyl-3-isoxazolidinyl] pyridine (Supplementary Figure S1 , Chen et al, 2014 ), developed by the China Shenyang Research Institute of Chemical Industry in 1997, has shown great promise for the control of a broad range of fungi and has been registered for the control of gray mold ( Botrytis cinerea ) on tomato in China under the trade name Junsiqi (25% EC, China Shenyang Research Institute of Chemical Industry, Shenyang, China) (Si et al, 2004 ). It has also been found that SYP-Z048 provides highly effective control of the closely related species Monilinia fructicola (G. Winter) Honey, a ubiquitous pathogen that is the primary causal agent of brown rot in stone fruit (EPPO/CABI 1 ).…”

Growth-inhibiting activity of citronella essential oil to multiple fungal plant pathogens

“…The effect of CEO on fungal mycelial growth was assessed in vitro following the procedure described by (Chen et al, 2014). Citronella essential oil was amended into PDA to achieve the test concentrations 0.25, 1.25 and 2.50 µL/mL PDA.…”

“…The mango pathogen was selected as representative fungal species for this assay because it was the most less sensitive fungus in the above assays. The method described by (Chen et al, 2014) was similarly used. One hundred µL of the conidial suspension was spread onto water agar (WA) containing 2.5 µL CEO/mL WA.…”

A complex game of hide and seek: the search for new antifungals

“…9), which contains a combination of pyridine and isoxazoline moieties. 152 This compound was designed for use as an agricultural fungicide. After extensive testing against several phytopathogenic fungi, SYP-Z048 was shown to be a broad-range antifungal agent and to work as both a protectant and curative.…”