Screening of Different Indian Wheat Varieties for Alpha Amylase Inhibitor Proteins/Genes to Develop Insect-Resistant Transgenic Plants

摘要

Alpha amylase inhibitors are naturally occurring defense molecules found in plants. Since starch is the major feeding substance in wheat, these molecules are selected to develop insect-resistant crop. Wheat alpha amylase inhibitors are monomeric, homodimeric and heterodimeric. We have screened different Indian wheat varieties by three methods to select the suitable one for isolation of gene. In an insect feeding trial method, it was found that HD21S9, UP2425 and UP262 supported very little growth ofRhizopertha dominica. The growth of Sitophilus oryzae was low on UP2382 and UP2425 while the growth of Tribolium castenum was also low on UP2382 and UP2425. An in vitro amylase inhibitor assay against the same insect alpha amylases revealed that Kundan was most effective against Rhizopertha amylase while UP2425 was maximally effective towards S. oryzae and T. castenum alpha amylase. Negative effect on the growth of 5. oryzae was observed when insect was reared upon inhibitor-coated wheat grains. A dot blot assay to screen the presence of alpha amylase inhibitor gene using pTd13.39 probe was also conducted. UP2425 showed strongest hybridization pattern with the probe. On the basis of these findings UP2425 was found to be the most suitable variety for isolation of alpha amylase inhibitor gene.