The altered photosynthetic machinery during compatible virus infection

As an organelle only found in plant cells and some protists, the chloroplast is not only the main metabolic energy originator, but also the abiotic/biotic stress sensor and defense signal generator. For a long time, chloroplasts have been recognized as a common target by many plant viruses. Viruses may directly modify chloroplast membranes to assemble their replication complex for viral genome replication. Viruses may downregulate chloroplast-related and photosynthesis-related genes via an as yet unknown mechanism to support their infection. Viruses may also interrupt functionality of the photosynthetic machinery through protein-protein interactions. This review briefly summarizes current knowledge about modifications of the photosynthetic machinery by plant viruses, highlights the important role of chloroplasts in the infection process and discusses chloroplast-associated pathogenesis.