Edinburgh, Scotland, United Kingdom - TAIR

Wide screening of phage-displayed protein
libraries to draw plant-pathogen interaction
maps
The interactions between plants and microorganisms in nature are complex and
diverse. In Arabidopsis, the availability of post-genomic tools makes possible
novel approaches to discover the molecular players involved in this diversity. We
have used a phage-display strategy to express Arabidopsis proteome during
microbial infection and to select for proteins able to bind microbial components.
To rapidly identify microbe-bound proteins in different plant pathosystems, we
developed a monitoring method using microarrays. This combined strategy
allowed for a genome-wide screening of plant genes involved in microbial
recognition.
Three phage-displayed libraries were constructed upon Arabidopsis infection
with Pseudomonas aeruginosa PA14, the virulent isolate DC3000 from P.
syringae Pto and an Avr isolate. These pathosystems represent different degrees
in the specificity of the plant-microbia interactions, which presumably involves a
large number of plant proteins. The libraries contain up to 2x10E7 plant
transcripts that are expressed as functional proteins fused to the capsid of T7bacteriophage.
These proteins and their corresponding genes have been
rescued by the ability of phagemic particles to bind living Pseudomonas cells, in
a so-called “biopanning” selection. Bound and unbound proteins have been
monitored along biopanning rounds by hybridisation of biopanned phage DNAs
with microarrays. This has lead to a set of 205 proteins that are potential targets
for microbe binding. The set includes BAK1 and FRK1, two previously known
receptors of bacterial effectors, the plant defensin PDF1.2 and several NBS-
LRR proteins, which are predicted to be involved in pathogenesis. The set also
contains 28 unknown proteins, which have been first related to pathogenesis in
this work. Our results show the potential of this phage-display-based strategy
for wide exploration of plant-microbia interactions and provide a new tool for
post-genomic research in plants.
68
C17
Wednesday 17:45 - 18:00
Tools and Resources
Cristina Rioja Llerena1
Inés Arrieta Aguirre,1
Keith A Charlton2
Susana García-Sánchez1
1NEIKER Institute-Tecnalia,
Vitoria
Spain
2Haptogen Ltd
Aberdeeen
UK