Chemoperception of Specific Amino Acids Controls Phytopathogenicity in Pseudomonas syringae pv. tomato
Metadata
Show full item recordEditorial
American Society for Microbiology
Materia
Chemoreceptors Pseudomonas syringae Virulence
Date
2019-10-01Referencia bibliográfica
Cerna-Vargas JP, Santamaría- Hernando S, Matilla MA, Rodríguez-Herva JJ, Daddaoua A, Rodríguez-Palenzuela P, Krell T, López-Solanilla E. 2019. Chemoperception of specific amino acids controls phytopathogenicity in Pseudomonas syringae pv. tomato. mBio 10:e01868-19. [https://doi .org/10.1128/mBio.01868-19]
Sponsorship
This work was supported by grants AGL2015-63851-R and RTI2018-095222-B100 (to E.L.-S.) and BIO2016-76779-P (to T.K.) from the Ministerio de Economía y Competitividad, Spain. J.P.C.-V. was supported by the FPI program (BES-2016-076452, MINECOSpain).Abstract
Chemotaxis has been associated with the pathogenicity of bacteria in
plants and was found to facilitate bacterial entry through stomata and wounds.
However, knowledge regarding the plant signals involved in this process is scarce.
We have addressed this issue using Pseudomonas syringae pv. tomato, which is a foliar
pathogen that causes bacterial speck in tomato. We show that the chemoreceptor
P. syringae pv. tomato PscA (PsPto-PscA) recognizes specifically and with high affinity
L-Asp, L-Glu, and D-Asp. The mutation of the chemoreceptor gene largely
reduced chemotaxis to these ligands but also altered cyclic di-GMP (c-di-GMP) levels,
biofilm formation, and motility, pointing to cross talk between different chemosensory
pathways. Furthermore, the PsPto-PscA mutant strain showed reduced virulence
in tomato. Asp and Glu are the most abundant amino acids in plants and in particular
in tomato apoplasts, and we hypothesize that this receptor may have evolved to
specifically recognize these compounds to facilitate bacterial entry into the plant. Infection
assays with the wild-type strain showed that the presence of saturating concentrations
of D-Asp also reduced bacterial virulence.