Chemical Composition of an Aphid Antifeedant Extract from an Endophytic Fungus, Trichoderma sp. EFI671

Abstract

Botanical and fungal biopesticides, including endophytes, are in high demand given the current restrictive legislations on the use of chemical pesticides. As part of an ongoing search for new biopesticides, a series of fungal endophytes have been isolated from selected medicinal plants including Lauraceae species. In the current study, an extract from the endophytic fungus Trichoderma sp. EFI 671, isolated from the stem parts of the medicinal plant Laurus sp., was screened for bioactivity against plant pathogens (Fusarium graminearum, Rhizoctonia solani, Sclerotinia sclerotiorum and Botrytis cinerea), insect pests (Spodoptera littoralis, Myzus persicae, Rhopalosiphum padi) and plant parasites (Meloidogyne javanica), with positive results against M. persicae. The chemical study of the neutral fraction of the active hexane extract resulted in the isolation of a triglyceride mixture (m1), eburicol (2), β-sitostenone (3), ergosterol (4) and ergosterol peroxide (5). The free fatty acids present in the acid fraction of the extract and in m1 (oleic, linoleic, palmitic and stearic) showed strong dose-dependent antifeedant effects against M. persicae. Liquid (potato dextrose broth, PDB and Sabouraud Broth, SDB) and solid (corn, sorghum, pearl millet and rice) growth media were tested in order to optimize the yield and bioactivity of the fungal extracts. Pearl millet and corn gave the highest extract yields. All the extracts from these solid media had strong effects against M. persicae, with sorghum being the most active. Corn media increased the methyl linoleate content of the extract, pearl millet media increased the oleic acid and sorghum media increased the oleic and linoleic acids compared to rice. The antifeedant effects of these extracts correlated with their content in methyl linoleate and linoleic acid. The phytotoxic effects of these extracts against ryegrass, Lolium perenne, and lettuce, Lactuca sativa, varied with culture media, with sorghum being non- toxic.

Revealing of biodiversity and antimicrobial effects of Artemisia asiatica endophytes

“…compounds (Toghueo et al 2019;Hellwig et al 2002;Kaushik et al 2020). Members of the Trichoderma genus were also found dominant in our study colonizing only the stems.…”

Identification of Substances Produced by Cercospora brachiata in Absence of Light and Evaluation of Antibacterial Activity

“…Some compounds identified by GC-MS can be highlighted because they are common among the extracts of the analyzed fungi, such as long-chain fatty acids (9-hexadecenoic, hexadecanoic, oleic, octadecanoic, lauric, myristic, palmitic, docos-13-enoic, stearic, linoleic, and nonadecanoic acids) [ 17 , 18 ].…”

Optimization of Insecticidal Triterpene Derivatives by Biomimetic Oxidations with Hydrogen Peroxide and Iodosobenzene Catalyzed by MnIII and FeIII Porphyrin Complexes

“…Spodoptera littoralis, Myzus persicae and Rhopalosiphum padi colonies are maintained at ICA-CSIC, reared on artificial diet, bell pepper (Capsicum annuum) and barley (Hordeum vulgare) plants, respectively, and kept at 22 � 1°C and > 70 % relative humidity, with a photoperiod of 16 : 8 h (L/D) in a growth chamber (Kaushik et al, 2020). [38] Antifeedant bioassays. The bioassays were conducted as described (Kaushik et al, 2020).…”

“…[38] Antifeedant bioassays. The bioassays were conducted as described (Kaushik et al, 2020). [38] Briefly, the upper surface of C. annuum and H. vulgare leaf disks or fragments (1.0 cm 2 ) were treated with an initial dose of 50 μg of the test substance.…”

“…The bioassays were conducted as described (Kaushik et al, 2020). [38] Briefly, the upper surface of C. annuum and H. vulgare leaf disks or fragments (1.0 cm 2 ) were treated with an initial dose of 50 μg of the test substance. Five Petri dishes or twenty plastic boxes (2 × 2 cm) with two newly molted S. littoralis L6 larvae (� 24 h after molting) or 10 apterous aphid adults (24-48 h old) each were allowed to choose between treated and control leaf disks/fragments (� 4 h for S. littoralis, 24 h, for the aphids).…”