An efficient virus‐induced gene silencing vector for maize functional genomics research

Abstract

Maize is a major crop whose rich genetic diversity provides an advanced resource for genetic research. However, a tool for rapid transient gene function analysis in maize that may be utilized in most maize cultivars has been lacking, resulting in reliance on time-consuming stable transformation and mutation studies to obtain answers. We developed an efficient virus-induced gene silencing (VIGS) vector for maize based on a naturally maize-infecting cucumber mosaic virus (CMV) strain, ZMBJ-CMV. An infectious clone of ZMBJ-CMV was constructed, and a vascular puncture inoculation method utilizing Agrobacterium was optimized to improve its utility for CMV infection of maize. ZMBJ-CMV was then modified to function as a VIGS vector. The ZMBJ-CMV vector induced mild to moderate symptoms in many maize lines, making it useful for gene function studies in critically important maize cultivars, such as the sequenced reference inbred line B73. Using this CMV VIGS system, expression of two endogenous genes, ZmPDS and ZmIspH, was found to be decreased by 75% and 78%, respectively, compared with non-silenced tissue. Inserts with lengths of 100-300 bp produced the most complete transcriptional and visual silencing phenotypes. Moreover, genes related to autophagy, ZmATG3 and ZmATG8a, were also silenced, and it was found that they function in leaf starch degradation. These results indicate that our ZMBJ-CMV VIGS vector provides a tool for rapid and efficient gene function studies in maize.

A Foxtail mosaic virus Vector for Virus-Induced Gene Silencing in Maize

“…More recently, a new CMV vector was published for VIGS in maize (Wang et al, 2016). Here, we attempt to compare and contrast FoMV with the BMV and CMV vectors, with the caveat that we have no direct experience with these other two vector systems.…”

“…Among these, the BMV and CMV vectors have the ability to infect and induce gene silencing in maize (Zea mays; Ding et al, 2006;Lee et al, 2015;Wang et al, 2016). There have been relatively few studies published on the application of BMV VIGS in maize (Ding et al, 2006;van der Linde et al, 2011;van der Linde and Doehlemann, 2013), suggesting that it has not been widely adopted for maize gene function analyses.…”

“…Six different viruses have been developed into viral vectors for VIGS applications in monocots to date: Barley stripe mosaic virus (Scofield et al, 2005), Brome mosaic virus (BMV; Ding et al, 2006), Cymbidium mosaic virus (Lu et al, 2007), Rice tungro bacilliform virus (Purkayastha et al, 2010), Bamboo mosaic virus together with its associated satellite RNA (Liou et al, 2014), and, most recently, Cucumber mosaic virus (CMV; Wang et al, 2016). Among these, the BMV and CMV vectors have the ability to infect and induce gene silencing in maize (Zea mays; Ding et al, 2006;Lee et al, 2015;Wang et al, 2016).…”

A Violaxanthin Deepoxidase Interacts with a Viral Suppressor of RNA Silencing to Inhibit Virus Amplification

“…Crude extracts from SCMV-infected maize leaf tissues were prepared as described previously (Zhu et al, 2014). Vascular puncture inoculation of maize kernels with SCMV was conducted as described previously (Wang et al, 2016).…”

Foxtail Mosaic Virus-Induced Gene Silencing in Monocot Plants

“…Very recently, Cucumber mosaic virus-based VIGS in maize is reported (Wang et al, 2016) BMV and BMV-based vectors are frequently used for VIGS in some monocot plants. However, both virus vectors do not work in many other monocot species and not all cultivars within a particular host species (Ding et al, 2006;Pacak et al, 2010).…”