Expression of a begomoviral DNAp gene in transgenic Nicotiana plants induced abnormal cell division

摘要

An increasing number of monopartite begomovirases are being identified that a satellite molecule (DNA(3) is required to induce typical symptoms in host plants. DNAp encodes a single gene (termed beta C1) encoded in the complementary-sense. We have produced transgenic Nicotiana benthamiana and N. tabacum plants expressing the beta beta C1 gene of a DNAp associated with Tomato yellow leaf curl China virus (TYLCCNV), under the control of the Cauliflower mosaic virus 35S promoter. Transgenic plants expressing beta C1 showed severe developmental abnormalities in both species. Microscopic analysis of sections of both transgenic and non-transgenic N. tabacum leaves showed abnormal outgrowths of transgenic N. tabacum to be due to disorganized cell division (hyperplasia) of spongy and palisade parenchyma. Immuno-gold labeling of sections with a polyclonal antibody against the beta C1 protein showed that the beta C1 protein accumulated in the nuclei of cells. The possible biological function of the beta C1 protein was discussed.