Submitted to: Plant Physiology and Biochemistry
Publication Type: Peer reviewed journal
Publication Acceptance Date: 8/29/2005
Publication Date: 10/28/2005
Citation: Lim, H., Ko, T., Lambert, K.N., Kim, H., Korban, S.S., Hartman, G.L., Domier, L.L. 2005. Soybean mosaic virus helper component-protease increases somatic embryo production and stabilizes transgene expression in soybean. Plant Physiology and Biochemistry. 43:1014-1021. Interpretive Summary: The introduction of agronomically desirable traits into crop plants by genetic engineering is becoming more routine. Yet, for many cultivated plants, the process is very inefficient and laborious. This is especially true for soybean. In this study, we showed that a single gene from Soybean mosaic virus increased two to three fold the number of transgenic soybean plants recovered from multiple soybean transformation experiments. The data also showed that the virus gene probably enhances the recovery of transgenic plants by preventing recipient plants from deactivating the foreign genes. This work will be of interest to researchers who are interested in increasing the efficiency of plant transformation and understanding plant responses to the introduction of foreign genetic material.
Technical Abstract: The efficiency of Agrobacterium-mediated transformation of soybean has increased recently. However, the production of hygromycin-resistant somatic embryos (HR-SEs) remains low and transgene expression often is not stable. In this study, Soybean mosaic virus (SMV) helper component protease (HC-Pro), a suppressor of post-transcriptional gene silencing, was used to enhance production of HR-SEs and stabilize transgene expression. When immature soybean cotyledonary explants were co-cultured with Agrobacterium harboring pCAMBIA1305.1 containing SMV HC-Pro, significantly more HR-SEs and transgenic plants were obtained than from the vector controls. GUS expression was significantly higher in 50-day-old transgenic plants expressing beta-glucuronidase (GUS) with HC-Pro and in SMV-infected GUS transgenic plants than in transgenic plants expressing GUS alone suggesting that SMV-HC-Pro enhanced recovery of HR-SEs by suppressing silencing of the hygromycin-resistance gene.