Genetic Editing of Tomato Golgi-Localized Nucleotide Sugar Transporter 1.1 Promotes Immunity Against Phytophthora infestans

TL;DR

Editing a tomato gene called SlGONST1.1 boosts resistance to a destructive plant disease without harming plant growth.

Contribution

This study confirms SlGONST1.1 as a susceptibility gene and reveals its role in plant immunity against late blight.

Findings

Genetically edited SlGONST1.1 tomato lines showed increased resistance to Phytophthora infestans.

The edited line had lower abscisic acid levels and reduced reactive oxygen species burst after pathogen exposure.

Defense-related genes were disproportionately up-regulated in the edited line.

Abstract

Background: Functional alleles of host plant susceptibility genes (S genes) can exacerbate the severity of diseases by enhancing pathogen compatibility. Genetic editing of the targeted host S genes has demonstrated remarkable efficacy in conferring broad-spectrum resistance across multiple crop species. We have previously identified a Golgi-localized Nucleotide Sugar Transporter 1 homolog (SlGONST1.1) in the host plant Solanum lycopersicum as a susceptibility gene towards late blight caused by Phytophthora infestans. Methods: In this study, we performed a detailed characterization of tissue-specific and P. infestans-inducible expression patterns of this gene, and the subcellular localization of its encoded protein product. Results: Similar to phenotypes of two reported Slgonst1.1 edited lines, two newly generated genetically edited lines of SlGONST1.1 demonstrated enhanced resistance against P. infestans without obvious growth and developmental abnormality. Phytohormonal quantifications and reactive oxygen species measurements showed that an Slgonst1.1 line had lower constitutive abscisic acid contents and depleted reactive oxygen species burst induced by pathogen-associated molecular pattern. Further comparative transcriptomic analyses revealed that the expression of defense-related genes is disproportionally up-regulated in the Slgonst1.1 line. Conclusions: In summary, our findings confirmed SlGONST1.1 as a functional host susceptibility gene towards late blight and shed light on the potential molecular mechanism underlying its function.

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