Influences of Synthetic Peptide D4E1 on Phosphomonoesterase Activity.

Cotton Seedling Disease is a fungal complex which results in millions of dollars of revenue loss per year ($10 million in Alabama alone).  There are no known cultivars that show resistance to Cotton Seedling Disease.  Previous research has shown that a synthetic antimicrobial peptide D4E1, which has been shown in vitro and in-plants to have broad spectrum antimicrobial action against many fungal orders.  D4E1 has been transformed into cotton seeds to examine the efficacy of this peptide on the control of Cotton Seedling Disease.  With the introduction of synthetic antimicrobial peptides as a means of conferring disease resistance, it is important that the potential impact on non-target organisms and processes.  The objective of this study is to evaluate the effect of D4E1 on phosphomonoesterase enzyme activity.  Three 150 x 150 ft test plots, over two field seasons,  were arranged in a completely randomized design and were assigned either one of 3 lines of cotton seed transformed with D4E1 (designated 357, 358, and 373), a control line containing a GUS marker gene, or a non-transgenic control consisting of the parent variety. Soil samples were subjected to phosphatase enzyme assays for both acid and alkaline conditions.    Results demonstrated that there was no difference shown between the phosphomonoesterase activity between the control and the treatments containing the synthetic peptide D4E1.