Biorepress of fumonisin B1 production and their phytotoxicity on growth and ultrastructures of Maize (Zea mays) Seedlings

The results clearly indicated that the seed germinibility in the presence of FB1 was decreased with increasing their concentration, whereas the germinibility was uncompletely ceased at high concentrations, a slight initial lag in germination observed at lowest concentration 28.57 µg /ml and highest  concentration 64.11 µg /ml,  respectively compared with the control. At concentration of FB1 (28.57 µg /ml), elongation of the hypocotyls and epicotyls in seedlings slightly inhibited compared with the control. Chlorophyll a and b content of seedlings of Zea mays decreased with increasing concentrations of Fumonisin B1. Chlorophyll a content  was 6.23, 3.88 and 3.91 (mg/ g fresh weight) at concentrations 28.57, 40.54 and 64.11 (µg /ml) of  Fumonisin B1 compared with the control  8.55 mg/ g fresh weight. The ultrastructural studies indicate that there were dramatic differences between the treated and untreated tissues of Zea mays seedlings with the toxin FB1_. The treated cells with FB1 are highly vacuolated compared with the untreated cells. Thin layer of external epidermis was observed in untreated cells while thick layer of external epidermis in treated cells was appeared.Sacchaaromyces cerevisiae reduced FB1 to 40.54 (µg /ml) compared with control 64.11(µg /ml) .On the other hand Trichoderma harizianum was more efficient in FB1productivity where productivity was reduced to 28.57 (µg /ml) with 44.56 %.