Year: 2012
Type: dissertation
Abstract: Aphids are economically important phloem-feeding insects that cause loss in plant \nproductivity worldwide. This occurs through the removal of photoassimilates and the \nvectoring of hundreds of plant viruses. Plants possess a complex immune system in order \nto defend themselves from a range of pathogens including bacteria and fungi. I aimed to \ndiscover if this immune system was also involved in defence against aphids. \nI found that aphids have proteins that trigger plant immune responses. The aphid \nMyzus persicae contains several protein elicitors with varying molecular weights. These \nproteins are perceived by the plants Nicotiana benthamiana and Arabidopsis thaliana. In \nA. thaliana the perception of a 3 to 10 kDa elicitor fraction requires the leucine-rich repeat \nreceptor-like kinase (LRR-RLK) BAK1, as a mutant in this gene was deficient in immune \nresponses activated by this elicitor. Plant recognition of the elicitor is unlikely to depend \non a single non-arginine-asparate (non-RD) RLK. \nIn addition, aphids possess the means to modulate the plant immune response. I \nhelped to identify three aphid effectors that modulate plant processes. I then investigated \nthe role of one of these effectors, a M. persicae chemosensory protein (CSP) known as \nMp10, in suppressing the immune responses triggered by the aphid elicitors. Mp10 is \nlikely to disrupt the function of plant genes near the top of the immune signalling cascade \nin N. benthamiana in order to suppress elicitor-triggered immunity. Surprisingly, the \nhomologs of this CSP in other aphids also show the same ability to suppress plant \nimmune responses, suggesting an important role for Mp10 in plant-aphid interactions. \nThis is the first report of a role for elicitor recognition by plants in aphid defence, the use \nof plant cell surface receptors to detect insects, and aphids’ attempts to suppress plant \nimmunity.
Author: David Prince
Language: English
Subfield: Insect Science
Domain: Life Sciences
SDG: Zero hunger
Open Access status: green
OpenAlex ID: W2039368405