Insects' Deterrent Flavonoids from Cynara cardunculus for Controlling Cotton Leafworm; Spodoptera littoralis. الفلافونیدات الرادعة للحشرات من نبات الخرشوف البری , سینارا کارینکولارس لمکافحة دودة ورق القطن.

Abstract

Globally, striving to find eco-friendly pest control agents increased day after day toward plant metabolites. Through current work, three flavonoids were isolated from Cynara cardunculus and identified as Apigenin, Luteolin, and Luteolin-7-O-glucoside using UV, IR, and MS spectrometry analyses. The three compounds were evaluated for their anti-feeding and deterrence activity against 4th instar larvae of cotton leafworm Spodoptera littoralis using both dual and no-choice leaf disk tests. results revealed that Luteolin-7-O-glucoside recorded the strongest insect antifeedant activities reached (74.50, 91.40%) followed by Apigenin (53.45% & 71.61%) in both choice tests respectively, while the antifeedant index of Luteolin did not exceed 22% in the concentration of 1000 ppm. Moreover, the activity of digestive enzymes; amylase, and invertase decreased significantly according to the deterrence activity level of the tested compound while protease activity showed non-significant changes in treated larvae. Noteworthy, the structure-feed deterrence activity relationships of flavonoids was observed and considered. Thus flavonoids can protect crop plants from insect infestation according their chemical structure.

An evolutionarily ancient Fatty Acid Desaturase is required for the synthesis of hexadecatrienoic acid, which is the main source of the bioactive jasmonate inMarchantia polymorpha

“…One explanation for this is the increased level of flavonoids, such as apigenin and luteolin derivatives, that are constitutively found in Mp fad5 mutants. These flavonoids have been shown to have antifeedant activity (Golawska & Lukasik, 2012; El Shafeiy & Abdelaziz, 2020) and thus may have contributed to the protection of the mutant plants. Furthermore, it has been found that ω3 VLPUFA (Very Long Chain PUFA) favours larvae development (Twining et al ., 2016), and therefore, the reduced levels in Mp fad5 may also contribute to the mutant plants’ success against herbivorous insects.…”