Virus Operation Control Centers

Abstract

The nucleic acids of plant viruses are the control centers that coordinate all activities associated with virus survival and propagation within cells, in whole plants and between organisms. Within cells, the viruses use a diversity of signaling mechanisms to assure the orderly production at specific subcellular locations of viral mRNAs, viral proteins, viral genomic nucleic acids, and viral particles and the export of infectious entities to neighboring cells. Within cells, viruses also signal their presence to the host cell machinery, establishing the conditions of coexistence of virus and plant in successful infections. At the plant level, the control centers direct the movement of infectious entities from one cell to another, into the vascular system, and into tissues remote from the site of initial infection. At the same time, the control centers condition the plant to be hospitable to virus reproduction and survival. They also cause the plant to issue signals to potential vectors guiding them to the plant to acquire the virus and encouraging their departure to further plants, in effect spreading the virus among multiple plants. The signals used in these processes include small molecules (hormones and volatiles), macromolecules with binding sites for other molecules (some being enzymatic), macromolecular structure conformations, genomic organizations, and others. Often, different viruses accomplish the same activity in completely different ways, although some common strategies are employed.