Lara P, Ortego F, Gonzalez-Hidalgo E, Castañera P, Carbonero P, Diaz I
Laboratorio de Bioqúimica y Biología Molecular, Dpto. de Biotecnología-UPM, E.T.S. Ingenieros Agrónomos, Madrid, Spain.
Transgenic Res. 2000 Jun;9(3):169-78. doi: 10.1023/a:1008905631440.
Nicotiana tabacum plants were transformed with the cDNA of barley trypsin inhibitor BTI-CMe under the control of the 35S CaMV promoter. Although the transgene was expressed and the protein was active in the homozygous lines selected, growth of Spodoptera exigua (Lepidoptera: Noctuidae) larvae reared on transgenic plants was not affected. The protease activity in larval midgut extracts after 2 days feeding on transformed tobacco leaves from the highest expressing plant showed a reduction of 25% in the trypsin-like activity compared to that from insects fed on non-transformed controls. The susceptibility of digestive serine-proteases to inhibition by BTI-CMe was confirmed by activity staining gels. This decrease was compensated with a significant induction of leucine aminopeptidase-like and carboxipeptidase A-like activities, while chymotrypsin-, elastase-, and carboxipeptidase B-like proteases were not affected.
在35S CaMV启动子的控制下，用大麦胰蛋白酶抑制剂BTI-CMe的cDNA转化烟草植株。尽管转基因在所选的纯合系中表达且蛋白质具有活性，但以转基因植物饲养的甜菜夜蛾（鳞翅目：夜蛾科）幼虫的生长未受影响。以表达量最高的转基因烟草叶片喂养2天后，幼虫中肠提取物中的蛋白酶活性显示，与以未转化对照喂养的昆虫相比，类胰蛋白酶活性降低了25%。通过活性染色凝胶证实了消化丝氨酸蛋白酶对BTI-CMe抑制的敏感性。这种降低被亮氨酸氨肽酶样和羧肽酶A样活性的显著诱导所补偿，而糜蛋白酶、弹性蛋白酶和羧肽酶B样蛋白酶未受影响。
