الفهرس 
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Abstract
The present work involved studying the effects of biotic stress as B. cinerea and abiotic stress elicitors as metribuzin, pretilachlor, butachlor, sewage and sludge on defense mechanism of broad bean. This study included the effects of these stress elicitors on plant growth parameters, photosynthetic pigments, anthocyanin, protein, carbohydrates and phytoalexins production in addition to the activities of key enzymes for antioxidant system and secondary metabolism.
The obtained results are summarized as follow:
• Differential reduction in fresh and dry weight and in photosynthetic pigments. Sewage exhibited the greatest reduction in fresh and dry weight of leaves and roots followed by B. cinerea. Meanwhile, B. cinerea followed by metribuzin exerted the highest decreases in the photosynthetic pigments (chlorophyll a, chlorophyll b and carotenoids). Metribuzin seemed most likely more stress inducer than the other two herbicides.
• Increases in anthocyanin concentration in both leaves and roots of broad bean. This enhancement was higher in leaves than roots. B. cinerea, sewage and sludge exhibited the highest value of anthocyanin.
• Accumulation of total soluble carbohydrate contents in leaves and roots particularly with the application of B. cinerea and sewage. Such accumulation was accompanied by reduction in the contents of insoluble carbohydrates.
• Reduction in protein content in leaves and roots. B. cinerea exerted the greatest reduction.
• SOD increases in leaves and roots after the application of all used treatments. Lesser increases were defected in samples treated with sludge in leaves and with B. cinerea in roots.
• Differential induction in GPX and GST in leaves and roots, although B. cinerea resulted in inhibition of the enzyme activities. Butachlor and pretilachlor were more inducers for both enzyme activities than the other treatments.
• Great enhancement in activities of PAL in leaves and roots which control the production of secondary metabolites. The magnitude of increase was most pronounced with butachlor followed by pretilachlor then by sewage and B. cinerea. There were also increases in activity of TAL and CI. Lesser increases were detected in TAL activity of leaves due to sewage treatment and of roots due to butachlor and metribuzin treatment. CI activity was slightly increased in leaves by pretilachlor and in roots by B. cinerea.
• There were great production of genistein and daidzein following application of either of the stress elicitors. The production of genistein was most pronounced with pretilachlor and metribuzin. Daidzein production was greater following treatment with sewage, sludge, B. cinerea and butachlor than the other treatments. Anyway there was no detection of glycitein nor glyceollin in plant tissues following either of the employed treatment.
• All used stress elicitors resulted in varied effects on resorcinol and catechol content. More production of resorcinol and catechol contents was restricted to butachlor and pretilachlor.
• The stress elicitors elevated the total phenol concentration. The magnitude of increase was most pronounced during the 7th day of treatments. The effect was more detected following treatment with sewage.
• The acidified methanolic extracts of leaves and roots that were used for anthocyanin were also tested for their potentiality as antibacterial against some bacterial species as B. subtilis, B. cereus, M. roseus, K. pneumonia and E. coli. There was a great efficiency of these extracts against B. cereus followed by K. pneumonia and mild effect against B. subtilis. Lesser activity of used extracts appeared against M. roseus. In contrast, no detection of any inhibition zones had been observed by E. coli in tested extracts.