Activity Analysis Of Two Protein Elicitors PeBC1 And PeBA1 Induced Resistance Against Green Peach Aphid(Myzus Persicae) On Common Bean(Phaseolus Vulgaris L).

Elicitors are Bio factor which induced resistance in plants against pathogen and insect pests.Bacterial microbe-associated molecular patterns?MAMPs?play a crucial role in innate plant immunity.Green peach aphid?Myzuspersicae?is one of the notorious and primary pests of kidney beans worldwide.It is also the vector of bean common virus disease?BCMV?.Due to increased incidence of BCMV epidemics,green peach aphid has become a major concern in bean cultivating regions.A wide range of the biological control techniques are being researched to control aphid infestation on bean crop among which microbial metabolites are emerging as promising pest control tool.This in vitro study evaluates the potential roles of two elicitors PeBC1 and PeBA1 in induced systemic resistance against green peach aphid?Myzus Persicae?.PeBC1extracted from a necrotrophic fungus Botrytis cinerea while PeBA1 extracted from Bacillus amyloliquefaciens NC6 strain.Three different concentration of both elicitors PeBC1 elicitor(i.e.33.56,25.43,19.33?g ml^-1),PeBA1(i.e.40.51,24.91 and 16.38 ugml^-1)were applied at three different temperature?i.e.18,21 and 25°C?for PeBC1 and for PeBA1?i.e.21,27 and 30°C?.Freshly molted?0-6 h old?apterous adult aphids were confined on bean plants treated with three different concentrations of both elicitors,respectively.And the nymphal developmental time and fecundity of aphids were determined.In addition to the biological parameters of aphids,the relative expression levels of key genes associated with jasmonic acid?JA?and salicylic acid?SA?plant defense pathways were also determined through RT-qPCR.Results of bioassays revealed a significant?p<0.05?sub-lethal effect of both elicitors on aphid life time parameters.Maximum elongation was observed at minimum temperature and minimum was observed at maximum temperature.Nymphal developmental time of aphids was significantly prolonged and the fecundity rate was significantly reduced by different concentrations of both elicitors applied at different temperature regimes.Aphids preferred to colonize buffer-treated plants than elicitors-treated plants.In addition,elicitors-treated plants exhibited an induced resistance against aphids as compared to buffer-treated?control?plants.Foliar application of both elicitors protein strongly up regulated the expression levels of SA pathway-associated genes while the expression of JA pathway-associated genes exhibited a moderate induction.The expression level of key genes associated with ethylene pathway was also upregulated in plants treated with elicitors PeBA1.Similarly,quantification by LC/MSMS revealed a linear increase of both plant hormones up to 6 h of elicitor application and then decreased.Our findings suggest both elicitors protein can be used as an effective biological pest management tool in against phloem-feeding insect pests such as green peach aphids M.persicae.