MANDUCA-SEXTA ENCODED PROTEASE INHIBITORS EXPRESSED IN NICOTIANA-TABACUM PROVIDE PROTECTION AGAINST INSECTS

Crop plants are damaged by a multitude of insect pests, lowering crop quality and yield. Here we have expressed insect encoded anti-trypsin, anti-chymotrypsin and anti-elastase protease inhibitor (PI) genes fro m Manduca sexta L. in transgenic Nicotiana tabacum L. under the contro l of the 35S promoter of cauliflower mosaic virus. PI levels accumulat ed in leaves to 0.05-0.1% of the total protein. When these plants were tested against the new Bemisia tabaci (Genn.), sweetpotato whitefly t ype B, insect reproduction was reduced by as much as 98% compared to c ontrols. This result suggests that M. sexta derived protease inhibitor s, together with other anti-insect genes and plant-encoded responses t o damage and attack, may be useful in protecting crop plants against i nsects.