Development of a novel fungicide, tolprocarb

• Published in: Journal of Pesticide Science Vol. 44; no. 3; pp. 208 - 213
• Main Authors: Hagiwara, Hiroyuki, Ezaki, Ryutaro, Hamada, Takahiro, Tsuda, Mikio, Ebihara, Koichi
• Format: Journal Article
• Language: English; Japanese
• Published: Tokyo Pesticide Science Society of Japan 20.08.2019; Japan Science and Technology Agency
• Subjects: Agricultural production; Bacterial diseases; Biosynthesis; Cross-resistance; Cytochrome; Cytochrome bc1; Cytochromes; Dehydration; Fungi; Fungicides; Health risks; Inhibitors; Magnaporthe grisea; MBI-P; Melanin; Melanin biosynthesis inhibitor; Mode of action; Organic chemistry; Oryza sativa; Pesticides; Polyketide synthase; Quinones; Rice; Rice blast; Rice fields; Society Awards 2019; Systemic acquired resistance; Xanthomonas oryzae pv. oryzae
• ISSN: 1348-589X; 1349-0923
• DOI: 10.1584/jpestics.J19-01

Tolprocarb developed by Mitsui Chemicals Agro, Inc. (Tokyo, Japan) was discovered as a new oomycete fungicide. However, its antifungal spectrum and action mechanisms against fungi are completely different from those of the original compound, iprovalicarb. Tolprocarb has a potent and highly controlled effect on a rice blast fungus Magnaporthe grisea, and its mode of action was revealed to be the inhibition of polyketide synthase in the melanin biosynthesis pathway. In addition, tolprocarb induced systemic acquired resistance in Arabidopsis thaliana and rice (Oryza sativa L.). Owing to these double modes of action, tolprocarb can effectively control not only rice blast but also bacterial diseases, and has a low risk of developing fungicide-resistant isolates. Tolprocarb also provides long-term residual activity. A meta-analysis was performed in order to demonstrate tolprocarb’s superior control against panicle blast in paddy fields. In addition, tolprocarb did not show cross-resistance against the fungi that are resistant to dehydratase inhibitor in melanin biosynthesis (Melanin Biosynthesis Inhibitor-Dehydratase; MBI-D) or respiratory complex III: cytochrome bc1 at Quinone outside site inhibitor (Quinone outside Inhibitor; QoI). Owing to its stable effects, tolprocarb appears to be a suitable choice for practical use against fungi in the rice production field.