Expression and subcellular compartmentation of Aspergillus niger β-glucosidase in transgenic tobacco result in an increased insecticidal activity on whiteflies (Bemisia tabaci)

Transgenic Nicotiana tabacum plants expressing Aspergillus niger b-glucosidase (EC 3.2.1.21) gene (BGL1) in different subcellular compartments [cell wall (Tcw), endoplasmic reticulum (Ter), and vacuole (Tvc)] were analyzed to study the effects of BGL1 localization on plant growth and plant‐insect interaction. Transgenic and non-transgenic plants were grown and characterized in a greenhouse with 25/16 8C day/ night temperatures and natural sunlight. Plant insecticidal activity was analyzed with adult whiteflies (Bemisia tabaci) in vial and cage experiments. Compared with wild-type controls, Ter and Tvc transgenic plants did not differ significantly in seed germination, plant growth rate, plant height, or flowering time. However, in Tcw seed germination and beginning of flowering were significantly delayed, and leaf area and plant fresh weight were significantly reduced. Transgenic plants had a marked insecticidal effect on whiteflies (Bemisia tabaci) and onDipteraspp.flies. The density of secretory glandular trichomes was significantly greater in transgenic than in wild-type leaves. This work indicates that hydrolysis of yet to be identified glycosides, may play an important role in plant insect resistance mechanism and plant trichome development. # 2007 Elsevier Ireland Ltd. All rights reserved.