LAUSR

Glandular trichomes, a specialized multicellular structure, are considered as biofactories due to their capability to synthesize and secrete a large amount of secondary metabolites. Tobacco leaves have a high density of glandular trichomes that produce huge amounts of secondary metabolites, which can be used as important industrial raw materials. However, molecular mechanism controling glandular trichome development in tobacco still remains largely unknown. In the present study, we found that NbGL3, an HD-Zip IV family gene from Nicotiana benthamiana, was highly expressed in mature leaves, and ethylene or auxin application could increase the expression of NbGL3. Virus induced gene silencing NbGL3 resulted in a decreased glandular trichome density on leaves. Putative downstream genes, such as micro trichome, cyclin B2, and wax inducer 1 like were down regulated in NbGL3 silenced plants. Our results demonstrate that NbGL3 could positively regulate initiation of glandular trichomes in tobacco.