<p>An increasing number of chloroplast proteins have been found
to interact with plant virus proteins. This is not surprising because these
viruses cause various mosaic, mottles, and chlorosis symptoms on host leaves
indicating damage to chloroplasts. A chloroplast protein, AtPsbP, was
identified in a yeast two-hybrid screen as interacting with <i>Alfalfa mosaic
virus</i> (AMV) coat protein (CP). AMV is a ssRNA virus with a wide host range
including Arabidopsis. AtPsbP is an
extrinsic subunit of photosystem II and with PsbQ is vital for water oxidation.
We found that an RNAi knock-down of PsbP in <i>Nicotiana tabacum</i>, allowed
increased replication of AMV and the development of quite severe disease
symptoms in comparison to a wild-type <i>N. tabacum</i>. This suggested that
PsbP plays an important role in plant resistance to AMV. PsbP, in addition to
its role in photosynthesis, has been reported to interact with a
wall-associated receptor kinase, WAK1, whereby it may affect plant defense
signaling. We found that AtPsbP is a link between AtWAK1 and AMV CP at the
plasma membrane. The formation of the AtWAK1-AtPsbP-AMV CP complex activated
WAK1 kinase activity causing phosphorylation of PsbP and significant inhibition
of AMV replication. We also found that the formation of the ternary complex
induced the activation of the MAPK signal pathway. Analysis of the
susceptibility of an Arabidopsis WAK1 knock-down indicated that WAK1, like
PsbP, is critical for inhibiting AMV replication. Overall, we found a unique
virus perception strategy, whereby a chloroplast protein (PsbP) interacts with
a virus protein and then a Receptor-like kinase protein (WAK1) to transduce
signals through the MAPK signaling pathway to activate defense responses.</p>
| Identifer | oai:union.ndltd.org:purdue.edu/oai:figshare.com:article/13355930 |
| Date | 15 December 2020 |
| Creators | Longfei Wang (9661535) |
| Source Sets | Purdue University |
| Detected Language | English |
| Type | Text, Thesis |
| Rights | CC BY 4.0 |
| Relation | https://figshare.com/articles/thesis/RECEPTOR_LIKE_KINASE_ACTIVITY_MODULATES_VIRAL_INFECTION_THROUGH_PHOSPHORYLATION_OF_A_CHLOROPLAST_PROTEIN/13355930 |
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