A geminivirus crosses monocot dicot boundary and enables genome editing

Authors: KUMAR, JITENDRA - University Of Minnesota; ALOK, ANSHU - University Of Minnesota; STEFFENSON, BRIAN - University Of Minnesota; Kianian, Shahryar

Submitted to: Journal of Advanced Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/18/2023
Publication Date: N/A
Citation: N/A

Interpretive Summary: The family Geminiviridae represent a major class of single-stranded DNA viruses and are studied due to the devastating diseases they cause to crops. Geminiviruses are ideal for developing viral vectors for genetic engineering as they multiply without integrating into the plant genome, can deliver DNA repair templates, replicate in high copy number, and are easy to manipulate and use. However, their use in genetic engineering is limited due to carrying capacity and restricted host range, which leads to the development of separate vectors for monocot and dicot plant species. Here we report for the first time a geminvirus, Wheat Dwarf India Virus (WDIV), that infects major crop species such as wheat, oat, barley, corn and soybean in addition to tobacco. Majority of the infected plants only showed mild symptoms of infection. We further used this virus to develop vectors for gene silencing and gene editing. Tobacco lines expressing Cas9 were infiltrated with a WDIV-based vector carrying gRNA targeting the PDS gene. We observed high efficiency genome editing in tobacco. Detection of WDIV in naturally infected wheat, barley and sugarcane in field and its ability to systemically infect wheat, oat, barley, corn, soybean, and tobacco under laboratory conditions, qualifies it as the first geminivirus identified with the capability of infecting both monocot and dicot plant species. The wide host range of WDIV can be exploited for developing a single vector system for tissue culture-free genome editing in many plant species.

Technical Abstract: Members of the family Geminiviridae have been reported to infect either a monocot plant or a dicot plant, but not both. This study reports a geminivirus, Wheat Dwarf India Virus (WDIV), first identified in wheat, that is capable of infecting both, monocot, and dicot plants and act as a viral vector. Here we used a wheat isolate of WDIV and AYLCB for infectivity and vector development. We performed agrobacterium-mediated inoculation of WDIV and AYLCB in wheat, oat, barley, corn, soybean, and tobacco. Majority of plants inoculated with WDIV or WDIV and AYLCB showed mild symptoms, whereas some plants showed more prominent symptoms. WDIV and AYLCB were detected from systemically infected leaves of all plant species tested. We further examined the potential of WDIV to act as a viral vector for silencing and expression. We modified the WDIV genome for silencing the phytoene desaturase (PDS) gene in wheat and tobacco. The WDIV based vector induced silencing of the PDS gene in both wheat and tobacco plants. For gene editing experiments, tobacco lines expressing Cas9 were infiltrated with a WDIV-based vector carrying gRNA targeting the PDS gene. We observed high efficiency genome editing in tobacco. Detection of WDIV in naturally infected wheat, barley and sugarcane in field and its ability to systemically infect wheat, oat, barley, corn, soybean, and tobacco under laboratory conditions, qualifies it as the first geminivirus identified with the capability of infecting both monocot and dicot plant species. The wide host range of WDIV can be exploited for developing a single vector system for tissue culture-free genome editing in many plant species.