Lateral organ boundaries 1 is a disease susceptibility gene for citrus bacterial canker disease

Abstract

Significance Citrus bacterial canker, which is caused by several species in the genus Xanthomonas , is a severe disease with worldwide distribution affecting all the commercially important citrus species and cultivars. The mechanisms of canker development, involving erumpent pustule formation and bacterial growth, are not known. Our findings suggest that virulence determinants in several pathogens activate a single host disease susceptibility (S) gene that has a critical contribution to bacterial growth and host pustule development. The S gene represents an excellent candidate for control measures for the citrus bacterial canker.

Intervention of Phytohormone Pathways by Pathogen Effectors

“…Turnip crinkle virus coat protein binds to the Arabidopsis NAC transcription factor TIP (TCV-INTERACTING PROTEIN1, also known as ANAC091) to interfere with defense response (Donze et al, 2014). More recently, Cs-LOB encoding a LOB (LATERAL ORGAN BOUNDRIES) domain transcription factor in citrus has been identified as a susceptibility gene whose product is targeted by the TAL effector pthA from Xanthomonas citri, the bacterial pathogen that causes bacterial canker disease in citrus (Hu et al, 2014;Z. Li et al, 2014).…”

Using Ecology, Physiology, and Genomics to Understand Host Specificity in Xanthomonas

“…Yet, some patterns of TAL activity are emerging, such as the induction of membrane transporters to provide nutrients in the apoplast, or of transcription factors leading to developmental changes within host tissues. Citrus bacterial canker was shown to rely on the PthA series of TAL effectors from X. citri, which are responsible for the formation of pustules upon the induction of the transcription factor CsLOB1 (63). Xoo induces members of the SWEET family of sugar (e.g., sucrose) efflux transporters to potentially feed the bacteria (reviewed in 66).…”

XA23 Is an Executor R Protein and Confers Broad-Spectrum Disease Resistance in Rice

“…Natural TALEs have a conserved architecture: an N-terminus required for the type III secretion system (TTSS)-dependent translocation of effectors into host cells, a central repeat region consisting of a varying number of mostly 34-amino-acid repeats (34-aa-repeats), and a C-terminus containing the nuclear localization signals and an acidic transcription activation domain (reviewed by Boch and Bonas, 2010). Pathogens inject their TALEs through the TTSS into plant cells to activate expression of the host susceptibility genes that contribute to disease (Yang et al, 2006;Hu et al, 2014;Li et al, 2014;Cernadas et al, 2014;Cohn et al, 2014). TALEs activate host gene expression by binding to the promoter sequences of host target genes.…”