Some Related Viral Agents
1.1 Introduction
Cucumber mosaic virus (CMV) is a typical member of the genus Cucumovirus. It has infected more than 1,000 species of monocots and dicots, including many economically important crops (Palukaitis and García-Arenal, 2003; Palukaitis et al., 1992). In China, CMV is commonly detected as the principal virus infecting field crops in the families Solanaceae (including tobacco, tomato, potato, pepper, etc.), Brassicaceae (including brassicas, radish, turnip, etc.) and Fabaceae
(including soybean, cowpea, etc.). As shown in Fig. 1.1, CMV strain containing a satellite RNA co-infected with Tomato mosaic virus (ToMV), brought fruit necrosis and killed off the whole plant when the temperature was high. CMV infection in early spring used to bring a major lost of radishes and other cruciferous crops.
Fig. 1.1. Symptoms caused by infection of Cucumber mosaic virus in the field
(a) Field tomato plant complexly infected by Cucumber mosaic virus with a satellite RNA and a strain of Tomato mosaic virus; (b) Field radish plant infected by CMV
1 Gene Cloning of Cucumber Mosaic Virus and Some Related Viral Agents
2
CMV can easily transmit mechanically to a wide range of plants. This characteristic makes it easier to do more research for virus-host interactions, and also for virus-virus interactions. Typical symptoms induced by CMV are supplied in Fig. 1.2. The rapid replication and high accumulation in leaf tissues of systemic hosts provide another advantage for genomic and quantitative studies. As shown in
Fig. 1.3, CMV particles reach a high accumulation condition within four days of inoculation in cells of the inoculated leaf. And the potyvirus infection also shows distinguished characteristics.
Fig. 1.2. Typical symptoms caused by inoculation of Cucumber mosaic virus
(a) Nicotiana glutinosa, presenting irregular yellowing spots on the inoculated leaves; (b)
Chenopodiu