Antifungal Traits of a 14 kDa Maize Kernel Trypsin Inhibitor Protein in Transgenic Cotton
Journal of Crop Improvement
Transgenic cotton plants expressing the maize kernel trypsin inhibitor protein (TIP) were produced and evaluated for antifungal traits. This 14 kDa trypsin inhibitor protein has been previously associated with resistance to aflatoxin-producing fungus Aspergillus flavus. Successful transformation of cotton (Gossypium hirsutum L.) and expression of trypsin inhibitor was demonstrated by PCR and Northern analysis, respectively. Proteins extracted from cottonseed and leaf tissues of transgenic
... of transgenic plants were separated using SDS-PAGE, and it indicated the presence of a 15-16 kDa protein in transgenic tissues as compared to control. Only transgenic cottonseed tissue reacted with the TIP antibody, indicating the expression in cottonseed. No cross-reaction to the TIP antibody was detected from leaf extracts, indicating the TIP was either not expressed or expressed at a level too low to be detected by Western blot. Crude leaf extracts from transgenic cotton plants did not show significant control of colonies from pre-germinated spores of A spergillus f l avus or Verticjf/jum dahljae; however, extracts from transgenic cottonseed tissue showed about 60% reduction of V. dahliae colonies, indicating the antifungal nature of the maize TIP by itself. Cotton bolls inoculated with a green fluorescent protein (GFP) expressing A. flavus strain showed no difference among controls or transgenic cotton plants indicating that the expression of TIP in cottonseed is not high enough to prevent A. flavus colonization.