Concomitant with this downregulation, several defence and cellular signalling genes were induced during PPV infection.
Further transcriptional profiling of protoplasts transfected with a PPV infectious clone revealed the upregulation of defence and cellular signalling genes as early as 6 hours post transfection.
These secreted proteins may disable plant defences and subvert cellular processes to suit the needs of invading pathogens.
Like adult corals, Acropora larvae infected with photosynthetic symbionts are more susceptible to thermal stress, exhibiting higher levels of antioxidant defences and oxidative cellular damage than those without symbionts [32].
This defence activation may be to the detriment of the plant, as fitness costs may often outweigh the benefits, because energy and resources are redirected toward defence, and normal cellular processes such as growth and yield are affected [ 24].
In the functional classification sequences belonging to four categories; "Cell Rescue, Defence and Virulence", "Cellular Communication/Signal Transduction Mechanism", "Metabolism" and "Transcription" were considered to be of great potential interest for cold acclimation.
Looking just at the two classes that we consider as most important for the cold acclimation process (Cell rescue, defence and virulence; Cellular communication and signal transduction) almost 40% of all sequences were homologous to potential cold stress related proteins.
Some of the differentially expressed genes are involved in detoxification pathways and cellular defences against insults.
Alternatively, the systemic maternal oxidative stress evident during pre-eclampsia could alter the delicate balance between the production of ROS and cellular defences in the neonate.
Pro-inflammatory genes, such as TNF-α and transcription factor NF-κB, have been reported to induce the expression of the genes associated with immunological and cellular defence systems [35,36].
