Abstract: The ability of agricultural and decorative plants to
absorb and detoxify TNT and RDX has been studied. All tested 8
plants, grown hydroponically, were able to absorb these explosives
from water solutions: Alfalfa > Soybean > Chickpea> Chikling vetch
>Ryegrass > Mung bean> China bean > Maize. Differently from
TNT, RDX did not exhibit negative influence on seed germination
and plant growth. Moreover, some plants, exposed to RDX
containing solution were increased in their biomass by 20%. Study of
the fate of absorbed [1-14ðí]-TNT revealed the label distribution in
low and high-molecular mass compounds, both in roots and above
ground parts of plants, prevailing in the later. Content of 14ðí in lowmolecular
compounds in plant roots are much higher than in above
ground parts. On the contrary, high-molecular compounds are more
intensively labeled in aboveground parts of soybean. Most part (up to
70%) of metabolites of TNT, formed either by enzymatic reduction
or oxidation, is found in high molecular insoluble conjugates.
Activation of enzymes, responsible for reduction, oxidation and
conjugation of TNT, such as nitroreductase, peroxidase,
phenoloxidase and glutathione S-transferase has been demonstrated.
Among these enzymes, only nitroreductase was shown to be induced
in alfalfa, exposed to RDX. The increase in malate dehydrogenase
activities in plants, exposed to both explosives, indicates
intensification of Tricarboxylic Acid Cycle, that generates reduced
equivalents of NAD(P)H, necessary for functioning of the
nitroreductase. The hypothetic scheme of TNT metabolism in plants
is proposed.
Abstract: The present study has been conducted to characterize
the prophenoloxidase (PPO) system of the desert locust, Schistocerca
gregaria following injection of Bacillus thuringiensis kurstaki (Bt).
The bulk of PPO system was associated with haemocytes and a little
amount was found in plasma. This system was activated by different
activators such as laminarin, lipopolysaccharide (LPS) and trypsin
suggesting that the stimulatory mechanism may involve an enzyme
cascade of one or more associated molecules. These activators did
not activate all the molecules of the cascade. Presence of
phenoloxidase activity (PO) coincides with the appearance of protein
band with molecular weight (MW) 70.154 KD (Kilo Dalton).