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Updated: Jul 20, 2025

Direct Agroinoculation of Maize Seedlings by Injection with Recombinant Foxtail Mosaic Virus and Sugarcane Mosaic Virus Infectious Clones
Published on: February 27, 2021
Development of cassava common mosaic virus-based vector for protein expression and gene editing in cassava
Decai Tuo1, Yuan Yao1, Pu Yan1
1National Key Laboratory for Tropical Crops Breeding, Key Laboratory of Biology and Genetic Resources of Tropical Crops (Ministry of Agriculture and Rural Affairs), Hainan Key Laboratory for Protection and Utilization of Tropical Bioresources, Institute of Tropical Bioscience and Biotechnology, Sanya Research Institute, Hainan Institute for Tropical Agricultural Resources, Chinese Academy of Tropical Agricultural Sciences, Haikou & Sanya, Hainan, China.
Background:
Plant virus vectors designed for virus-mediated protein overexpression (VOX), virus-induced gene silencing (VIGS), and genome editing (VIGE) provide rapid and cost-effective tools for functional genomics studies, biotechnology applications and genome modification in plants. We previously reported that a cassava common mosaic virus (CsCMV, genus Potexvirus)-based VIGS vector was used for rapid gene function analysis in cassava. However, there are no VOX and VIGE vectors available in cassava.
Results:
In this study, we developed an efficient VOX vector (CsCMV2-NC) for cassava by modifying the CsCMV-based VIGS vector. Specifically, the length of the duplicated putative subgenomic promoter (SGP1) of the CsCMV CP gene was increased to improve heterologous protein expression in cassava plants. The modified CsCMV2-NC-based VOX vector was engineered to express genes encoding green fluorescent protein (GFP), bacterial phytoene synthase (crtB), and Xanthomonas axonopodis pv. manihotis (Xam) type III effector XopAO1 for viral infection tracking, carotenoid biofortification and Xam virulence effector identification in cassava. In addition, we used CsCMV2-NC to deliver single guide RNAs (gMePDS1/2) targeting two loci of the cassava phytoene desaturase gene (MePDS) in Cas9-overexpressing transgenic cassava lines. The CsCMV-gMePDS1/2 efficiently induced deletion mutations of the targeted MePDS with the albino phenotypes in systemically infected cassava leaves.
Conclusions:
Our results provide a useful tool for rapid and efficient heterologous protein expression and guide RNA delivery in cassava. This expands the potential applications of CsCMV-based vector in gene function studies, biotechnology research, and precision breeding for cassava.

