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SUMMARY:Host Age-dependent Evolution of a Plant RNA Virus - Professor Sant
 iago F. Elena\, Instituto de Biologia Integrativa de Sistemas
DTSTART:20220505T120000Z
DTEND:20220505T130000Z
UID:TALK171842@talks.cam.ac.uk
CONTACT:Jake Harris
DESCRIPTION:As organisms age\, their metabolism and immunity change\, whic
 h may result in a different response to pathogens.  Therefore\, the intera
 ction of a host with its pathogens may vary along the organism’s lifetim
 e.  How this interplay between host age and pathogens affects virus evolut
 ion hasn’t been thoroughly studies.\n\nIn this work\, we used the pathos
 ystem Arabidopsis thaliana – Turnip mosaic potyvirus to characterize pla
 nt-virus interaction and virus evolution at three developmental stages: ve
 getative\, bolting (transition from vegetative to reproductive) and reprod
 uctive growth.  We inoculated plants at these stages with two viral strain
 s\, one naïve and other well-adapted to A. thaliana.  We observed that bo
 th viral strains had higher infectivity and induced stronger symptoms in o
 lder plants.  To study how these differences in the plant-virus interactio
 n may influence virus evolution\, we experimentally evolved both strains i
 n each one of the three host stages.  After evolution\, we observed that t
 he disease progression was faster in all the evolved virus in comparison w
 ith the ancestral one.  However\, viruses evolved in young hosts were sele
 cted to have a bigger increase in disease severity.  This relative increas
 e of disease severity was higher in the naïve strain than in the well-ada
 pted one.  The sequence of the evolved virus genomes showed that all virus
 es evolved from the naïve strain had mutations in the VPg protein involve
 d in genome amplification\, independently of the host stage were viruses e
 volved.  For the viruses evolved from the preadapted strain\, that already
  had fixed mutations in VPg\, the mutation pattern was different: viruses 
 evolved in young plants did not have any non-synonymous mutation while bol
 ting and flowered hosts selected for mutations in the NIaPro protease.  Th
 e virulence of the infection was age-dependent: while all evolved viruses 
 cause a significant reduction in seed production\, hosts infected during t
 heir reproductive stage produced significatively more offspring than host 
 infected at other developmental stages.  Next\, we characterized the trans
 criptional responses of all hosts to infection\, finding that despite the 
 biological processes involved in the response are similar against all evol
 ved virus\, each host stage has a particular set of genes that are fine-tu
 ne regulated in coordination with the hormonal response of the host.  Fina
 lly\, a metabolomic analysis points ABA as a key component of the differen
 tial response.  Overall\, our study contributes to understand the impact o
 f host age on host-virus interactions and how it conditions the evolution 
 of viruses.\n\nDue to having to go online\, we are restricting the talks t
 o University of Cambridge and alumni to keep them as informal as possible.
 \n\nContact reception@plantsci.cam.ac.uk for a Zoom link prior to a talk i
 f you are not on our mailing list.
LOCATION:Online
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