Proteomics and transcriptomics of the BABA-induced resistance response in potato using a novel functional annotation approach.
BACKGROUND
Induced resistance (IR) can be part of a sustainable plant protection strategy against important plant diseases. β-aminobutyric acid (BABA) can induce resistance in a wide range of plants against several types of pathogens, including potato infected with Phytophthora infestans. However, the molecular mechanisms behind this are unclear and seem to be dependent on the system studied. To elucidate the defence responses activated by BABA in potato, a genome-wide transcript microarray analysis in combination with label-free quantitative proteomics analysis of the apoplast secretome were performed two days after treatment of the leaf canopy with BABA at two concentrations, 1 and 10 mM.


RESULTS
Over 5000 transcripts were differentially expressed and over 90 secretome proteins changed in abundance indicating a massive activation of defence mechanisms with 10 mM BABA, the concentration effective against late blight disease. To aid analysis, we present a more comprehensive functional annotation of the microarray probes and gene models by retrieving information from orthologous gene families across 26 sequenced plant genomes. The new annotation provided GO terms to 8616 previously un-annotated probes.


CONCLUSIONS
BABA at 10 mM affected several processes related to plant hormones and amino acid metabolism. A major accumulation of PR proteins was also evident, and in the mevalonate pathway, genes involved in sterol biosynthesis were down-regulated, whereas several enzymes involved in the sesquiterpene phytoalexin biosynthesis were up-regulated. Interestingly, abscisic acid (ABA) responsive genes were not as clearly regulated by BABA in potato as previously reported in Arabidopsis. Together these findings provide candidates and markers for improved resistance in potato, one of the most important crops in the world.
Therese
T
Bengtsson
Deborah
D
Weighill
Estelle
E
Proux-Wéra
Fredrik
F
Levander
Svante
S
Resjö
Dharani Dhar
DD
Burra
Laith Ibrahim
LI
Moushib
Pete E
PE
Hedley
Erland
E
Liljeroth
Dan
D
Jacobson
Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Box 102, SE-230 53 Alnarp, Sweden. erik.alexandersson@slu.se.
Erik
E
Alexandersson
Erik
E
Andreasson
D010838:Phytophthora / Q000472:pathogenicity; D040901:Proteomics; D011198:Solanum tuberosum / Q000235:genetics / Q000378:metabolism* / Q000382:microbiology; D059467:Transcriptome