ABSTRACT
Viral infection of a plant can lead to a multitude of symptoms, some immediately apparent and others requiring microscopic examination. Many are accompanied by profound bio-chemical and physiological changes. This chapter describes some of the biochemical and physiological perturbations in virus-infected plants, and evaluates them in the context of the phenotypic expression of infection. Accumulation of starch is also a common feature of virus-infected tissue, chloroplasts often containing large numbers of enlarged granules. The effects of virus infection on various aspects of respiration, as with effects on photosynthesis, have been investigated in plants of several species infected with a selection of different viruses, although here, perhaps tobacco has figured even more prominently. Systemic infection has usually been found to stimulate, often only marginally, the rate of respiration when measured either as oxygen consumption or carbon dioxide evolution.
