Affiliation:
1. College of Plant Health and Medicine, Qingdao Agricultural University, Qingdao 266109, China
2. College of Chemistry and Pharmacy, Qingdao Agricultural University, Qingdao 266109, China
3. Shandong Key Laboratory of Applied Mycology, Qingdao Agricultural University, Qingdao 266109, China
Abstract
Weed and soil-borne pathogens could synergistically affect vegetable growth and result in serious losses. Investigation of agricultural bioactive metabolites from marine-derived fungus Alternaria iridiaustralis yielded polyketides (1–4), benzopyrones (5–7), meroterpenoid derivatives (8), and alkaloid (9). The structures and absolute configurations of new 1, 3, 5–6, and 8 were elucidated by extensive spectroscopic analyses, as well as comparisons between measured and calculated ECD and 13C NMR data. Compounds 1–4, 6, and 9 showed herbicidal potentials against the radicle growth of Echinochloa crusgalli seedlings. Especially 9 exhibited inhibition rates over 90% at concentrations of 20 and 40 μg/mL, even better than the commonly used chemical herbicide acetochlor. Furthermore, 9 also performed a wide herbicidal spectrum against the malignant weeds Digitaria sanguinalis, Portulaca oleracea, and Descurainia sophia. Compounds 5–8 showed antifungal activities against carbendazim-resistant strains of Botrytis cinerea, with minimum inhibitory concentration (MIC) values ranging from 32 to 128 μg/mL, which were better than those of carbendazim (MIC = 256 μg/mL). Especially 6 exhibited integrated effects against both soil-borne pathogens and weed. Overall, marine-derived fungus A. iridiaustralis, which produces herbicidal and antifungal metabolites 1–9, showed the potential for use as a microbial pesticide to control both weed and soil-borne pathogens.
Funder
Natural Science Foundation of China
Innovation Improvement Project of Scientific and Technological Minor Enterprises of Shandong Province
Qingdao Science and Technology Demonstration Project for Agriculture Innovation
Subject
Plant Science,Ecology, Evolution, Behavior and Systematics,Microbiology (medical)
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