Nematicidal Activity of Grammicin Biosynthesis Pathway Intermediates in <i>Xylaria grammica</i> KCTC 13121BP against <i>Meloidogyne incognita</i>
Yoon Jee Kim,
Kalaiselvi Duraisamy,
Min-Hye Jeong,
Sook-Young Park,
Soonok Kim,
Yookyung Lee,
Van Thi Nguyen,
Nan Hee Yu,
Ae Ran Park,
Jin-Cheol Kim
Affiliations
Yoon Jee Kim
Department of Agricultural Chemistry, Institute of Environmentally Friendly Agriculture, College of Agriculture and Life Science, Chonnam National University, Gwangju 61186, Korea
Kalaiselvi Duraisamy
Department of Agricultural Chemistry, Institute of Environmentally Friendly Agriculture, College of Agriculture and Life Science, Chonnam National University, Gwangju 61186, Korea
Min-Hye Jeong
Department of Plant Medicine, Sunchon National University, Suncheon 57922, Korea
Sook-Young Park
Department of Plant Medicine, Sunchon National University, Suncheon 57922, Korea
Soonok Kim
Biological and Genetic Resources Assessment Division, National Institute of Biological Resources, 42 Hwangyeong-ro, Incheon 22689, Korea
Yookyung Lee
Department of Agricultural Chemistry, Institute of Environmentally Friendly Agriculture, College of Agriculture and Life Science, Chonnam National University, Gwangju 61186, Korea
Van Thi Nguyen
Department of Agricultural Chemistry, Institute of Environmentally Friendly Agriculture, College of Agriculture and Life Science, Chonnam National University, Gwangju 61186, Korea
Nan Hee Yu
Department of Agricultural Chemistry, Institute of Environmentally Friendly Agriculture, College of Agriculture and Life Science, Chonnam National University, Gwangju 61186, Korea
Ae Ran Park
Department of Agricultural Chemistry, Institute of Environmentally Friendly Agriculture, College of Agriculture and Life Science, Chonnam National University, Gwangju 61186, Korea
Jin-Cheol Kim
Department of Agricultural Chemistry, Institute of Environmentally Friendly Agriculture, College of Agriculture and Life Science, Chonnam National University, Gwangju 61186, Korea
Grammicin, a polyketide metabolite produced by the endolichenic fungus Xylaria grammica KCTC 13121BP, shows strong nematicidal activity against Meloidogyne incognita. This study was performed to elucidate the grammicin biosynthesis pathway of X. grammica KCTC 13121BP and to examine the nematicidal activity of the biosynthesis intermediates and derivatives against M. incognita. Two grammicin biosynthesis intermediates were isolated from a T-DNA insertion transformant (strain TR-74) of X. grammica KCTC 13121BP and identified as 2-(hydroxymethyl)cyclohexa-2,5-diene-1,4-dione (compound 1) and 2,5-dihydroxybenzaldehyde (compound 2), which were also reported to be intermediates in the biosynthesis pathway of patulin, an isomer of grammicin. This indicates that the grammicin biosynthesis pathway overlaps almost with that of patulin, except for the last few steps. Among 13 grammicin biosynthesis intermediates and their derivatives (except grammicin), toluquinol caused the highest M. incognita J2 mortality, with an LC50/72 h value of 11.13 µg/mL, which is similar to grammicin with an LC50/72 h value of 15.95 µg/mL. In tomato pot experiments, the wettable powder type formulations (WP) of toluquinol (17.78 µg/mL) and grammicin (17.78 µg/mL) also effectively reduced gall formation on the roots of tomato plants with control values of 72.22% and 77.76%, respectively, which are much higher than abamectin (16.67%), but lower than fosthiazate (100%). The results suggest that toluquinol can be used directly as a biochemical nematicide or as a lead molecule for the development of new synthetic nematicides for the control of root-knot nematode diseases.
