Genetic dissection of Verticillium wilt resistance mediated by tomato Ve1.

Emilie F Fradin,Chun-Ming Liu,Bart P H J Thomma,Juan C Juarez Ayala,Christian D M Castroverde,Jane Robb,Ross N Nazar,Zhao Zhang

doi:10.1104/pp.109.136762

Abstract

Vascular wilt diseases caused by soil-borne pathogens are among the most devastating plant diseases worldwide. The Verticillium genus includes vascular wilt pathogens with a wide host range. Although V. longisporum infects various hosts belonging to the Cruciferaceae, V. dahliae and V. albo-atrum cause vascular wilt diseases in over 200 dicotyledonous species, including economically important crops. A locus responsible for resistance against race 1 strains of V. dahliae and V. albo-atrum has been cloned from tomato (Solanum lycopersicum) only. This locus, known as Ve, comprises two closely linked inversely oriented genes, Ve1 and Ve2, that encode cell surface receptor proteins of the extracellular leucine-rich repeat receptor-like protein class of disease resistance proteins. Here, we show that Ve1, but not Ve2, provides resistance in tomato against race 1 strains of V. dahliae and V. albo-atrum and not against race 2 strains. Using virus-induced gene silencing in tomato, the signaling cascade downstream of Ve1 is shown to require both EDS1 and NDR1. In addition, NRC1, ACIF, MEK2, and SERK3/BAK1 also act as positive regulators of Ve1 in tomato. In conclusion, Ve1-mediated resistance signaling only partially overlaps with signaling mediated by Cf proteins, type members of the receptor-like protein class of resistance proteins.

Highlights

Vascular wilt diseases caused by soil-borne pathogens are among the most devastating plant diseases worldwide
While V. longisporum infects various hosts that belong to the Cruciferaceae, including cabbage (Brassica oleracea var capitata), cauliflower (Brassica oleracea), and rapeseed (Brassica napus), V. dahliae and V. albo-atrum are responsible for monocyclic vascular wilt diseases in over 200 dicotyledonous species, including economically important crops (Pegg and Brady, 2002; Fradin and Thomma, 2006)
To study the composition of the Ve locus in resistant and susceptible tomato genotypes, the coding sequences (CDSs) of Ve1 and Ve2 homologs were amplified from genomic DNA of the tomato cultivars MoneyMaker (LA2706), which is susceptible to race 1 strains of Verticillium, and Motelle (LA2823) and VFN8 (LA1022), which are

Summary

Introduction

Vascular wilt diseases caused by soil-borne pathogens are among the most devastating plant diseases worldwide. V. longisporum infects various hosts belonging to the Cruciferaceae, V. dahliae and V. albo-atrum cause vascular wilt diseases in over 200 dicotyledonous species, including economically important crops. A locus responsible for resistance against race 1 strains of V. dahliae and V. albo-atrum has been cloned from tomato (Solanum lycopersicum) only This locus, known as Ve, comprises two closely linked inversely oriented genes, Ve1 and Ve2, that encode cell surface receptor proteins of the extracellular leucine-rich repeat receptor-like protein class of disease resistance proteins. While V. longisporum infects various hosts that belong to the Cruciferaceae, including cabbage (Brassica oleracea var capitata), cauliflower (Brassica oleracea), and rapeseed (Brassica napus), V. dahliae and V. albo-atrum are responsible for monocyclic vascular wilt diseases in over 200 dicotyledonous species, including economically important crops (Pegg and Brady, 2002; Fradin and Thomma, 2006). It was recently demonstrated that posttranscriptional gene silencing governs basal defense against Verticillium in Arabidopsis (Arabidopsis thaliana; Ellendorff et al, 2009)

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Conclusion