Genomic evaluation of oxalate-degrading transgenic soybean in response to Sclerotinia sclerotiorum infection

• Published in: Molecular plant pathology Vol. 15; no. 6; pp. 563 - 575
• Main Authors: Calla, Bernarda, Blahut-Beatty, Laureen, Koziol, Lisa, Zhang, Yunfang, Neece, David J, Carbajulca, Doris, Garcia, Alexandre, Simmonds, Daina H, Clough, Steven J
• Format: Journal Article
• Language: English
• Published: Blackwell Science in collaboration with the British Society of Plant Pathology 2014
• Subjects: complementary DNA; disease resistance; gene expression; genes; genotype; hypersensitive response; lignin; metabolites; microarray technology; oxalate oxidase; oxalic acid; oxidation; pathogens; photosynthesis; Sclerotinia sclerotiorum; signal transduction; soybeans; transcriptome; transgenic plants
• ISSN: 1364-3703

Oxalate oxidases catalyze the degradation of oxalic acid (OA). Highly resistant transgenic soybean carrying an oxalate oxidase (OxO) gene and its susceptible parent soybean line, AC Colibri, were tested for genome-wide gene expression in response to the necrotrophic, OA producing pathogen Sclerotinia sclerotiorum using soybean cDNA microarrays. The genes with changed expression at statistically significant levels (overall F-Test p-value cutoff of 0.0001) were classified into functional categories and pathways, and were analyzed to evaluate the differences in transcriptome profiles. Although many genes and pathways were found similarly activated or repressed in both genotypes after inoculation with S. sclerotiorum, the OxO genotype displayed a measurably faster induction of basal defense responses as observed by the differential changes of defense related and secondary metabolite genes compared to its susceptible parent AC. Additionally, the experiment presented provides data on several other transcripts that support the hypothesis that S. sclerotiorum at least partially elicits the hypersensitive response, induces lignin synthesis (cinnamoyl CoA reductase) and elicits not-yet-studied signaling pathways (G protein coupled receptor and related). Of the nine genes showing the most extreme opposite directions of expression between genotypes, eight of them were related to photosynthesis and/or oxidation, highlighting the importance of redox in control of this pathogen.