Activity Analysis Of Entomopathogenic Fungus Beauveria Bassiana ARSEF 2860 And Protein Elicitor(PeBA1)against Bemisia Tabaci

1.The whitefly is one of the most damaging pests in field crops as well as in greenhouses.The present study aimed to evaluate the in vitro pathogenicity of 2 fungus strains of Beauveria bassiana?BB-72 and BB-252?and one strain of Lecanicillium lecanii?V2?against the whitefly?B.tabaci?at 4 different temperature degrees 20,24,28,and 32°C,using a spray method.Three different bioassays were carried out comprised of conidial concentrations and filtrate of fungal strains,BB-72,BB-252 and V-2,and their binary combinations.The 1.5 ml of fungal filtrate was used in filtrate bioassay for each strain of fungus.Three different concentrations(1×10⁶ 1×10⁷ and 1×10⁸ conidial ml^-1)were used in conidial bioassay for each strain of fungus,whereas in bioassay for binary combination?1 ml conidia+1 ml filtrate?of BB-72×BB-72,BB-252×BB-252,and V2×V2 were used for these strains of fungus.According to the outcomes,the maximum mortality against whiteflies was observed on 12th day post-treatment.In conidial bioassay,the maximum mortality of B.tabaci was observed in BB-72 isolate?84%?,BB-252 isolate?77%?,and V-2 isolate?67%?at the highest concentration(1×10⁸ conidial ml^-1)at 24°C,and minimum mortality was recorded in BB-72 isolate?33%?,BB-252 isolate?29%?,and V-2 isolate?19%?at the lowest concentration 1×10⁶ conidia ml^-11 at 32°C on 12th day post-treatment.Infiltrate bioassay,BB-72 isolate exhibited maximum mortality?92%?at 24°C,and V-2 isolate showed minimum mortality?34%?at 32°C on 12th day post-treatment.Furthermore,in binary combination bioassay,the highest whitefly mortality was recorded in BB-72×BB72 isolate?87%?,BB-252×BB-252 isolate?73%?,and V2×V2isolate?65%?at 24°C and the lowest mortality in BB-72×BB-72 isolate?57%?,BB-252×BB-252isolate?50%?,and V2×V2 isolate?39%?at 32°C on 12th day post-treatment.In all bioassays,the BB-72 isolate was the utmost virulent,and application of its filtrate was found to be the most impressive against B.tabaci.2.Many biocontrol fungi synthesize proteins that elicit induced plant resistance against phytophagous pests.This in vitro trial illuminates the sublethal effect of partially-purified protein from the entomopathogenic fungus Beauveria bassiana strain ARSEF?2860 Bemisia tabaci?hemiptera:allyrodidae?,an economically significant plague for many solanaceous species,including tomatoes.Bioassays have been carried out to assess the effect of different protein concentrations?i.e.1.5,3 and 6?l/ml?on the longevity and fecundity of the B.tabaci on tomato?Lycopersicon esculentum?plants.Furthermore,expression analysis of key genes associated with salicylic acid?SA?and jasmonic acid?JA?pathways using RT-qPCR assessed the potential role of this exogenous protein in the plant defense mechanism.The findings showed that all protein concentrations had a substantial negative impact on B.tabaci survival and fecundity.The highest concentration?6?l/ml?resulted in lowest survival?40%?of whitefly at 8^th day post-treatment,while two other concentrations?3 and 1.5?l/ml?resulted in 61 and70%survival rate,respectively.Similarly,lowest and highest mean fecundity rates were recorded for the highest protein concentration and the control(1.8 and 3.3 eggs day^-1 female^-1),respectively.Moreover,B.bassiana-derived protein strongly up regulated the SA associated genes PR1,BGL2,EDS1 and PAL,and moderately up regulated the JA associated genes LOX,AOS,OPR3 and AOC in protein-treated tomato plants compared to the control plants.These findings demonstrate the systemic resistance induced in tomato plants against B.tabaci by the exogenous application of partially-purified protein extracted from B.bassiana suggesting the purification and further evaluation as a novel biological pest control method against whitefly and other sucking insect pests.3.Elicitors are Bio factor which induced resistance in plants against pathogen and insect pests.Bacterial microbe-associated molecular patterns?MAMPs?play a vital part in innate plant immunity.This study of protein elicitor PeBA1 which derived from a beneficial bacteria Bacillus amyloliquefaciens NC6strain and its putative role in induced systemic resistance in tomato against whitefly Bemisia tabaci.During the experiment for determining the effect elicitor protein activity against whitefly B.tacaci three different concentrations of PeBA1?45.52,26.80 and 18.36?g/ml?were applied to tomato plants at 4 leaf stage and exposed to newly adult whitefly.Bioassay results showed significant?p<0.05?sub-lethal effects of the exogenous application of PeBA1 elicitor against B.tabaci.Moreover,the RTqPCR gene expression analyses showed a significant up-regulation of most of the key genes linked to salicylic acid?SA?and jasmonic acid?JA?treated plants.These results not only recommend the putative utilization of PeBA1 elicitor protein in future biological pest control methods and against phloem-feeding insect pests such as B.tacaci but also help in improved comprehension of the mechanisms through which beneficial bacterial trigger the induced plant resistance.