Comparative transcriptome profiling of potato cultivars infected by late blight pathogen Phytophthora infestans: Diversity of quantitative and qualitative responses

Abstract

The Estonia potato cultivar Ando has shown elevated field resistance to Phytophthora infestans, even after being widely grown for over 40 years. A comprehensive transcriptional analysis was performed using RNA-seq from plant leaf tissues to gain insight into the mechanisms activated for the defense after infection. Pathogen infection in Ando resulted in about 5927 differentially expressed genes (DEGs) compared to 1161 DEGs in the susceptible cultivar Arielle. The expression levels of genes related to plant disease resistance such as serine/threonine kinase activity, signal transduction, plant-pathogen interaction, endocytosis, autophagy, mitogen-activated protein kinase (MAPK), and others were significantly enriched in the upregulated DEGs in Ando, whereas in the susceptible cultivar, only the pathway related to phenylpropanoid biosynthesis was enriched in the upregulated DEGs. However, in response to infection, photosynthesis was deregulated in Ando. Multi-signaling pathways of the salicylic-jasmonic-ethylene biosynthesis pathway were also activated in response to Phytophthora infestans infection.

Highlights

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  Potato cultivar Ando has maintained a long-lasting high-field resistance to Phytophthora infestans.

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  A comparative transcriptome analysis was performed to gain insights into its resistance mechanism.

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  Compared to a susceptible cultivar, about a five-fold greater number of differentially expressed genes were found in the highly resistant cultivar Ando.

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  Several disease-resistant pathways were significantly enriched in Ando and photosynthesis was deregulated.

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  Multi-signaling pathways of the salicylic-jasmonic-ethylene biosynthesis pathway were also activated in response to P. infestans infection at 72 h post-inoculation.