Xanthomonas citri subsp. citri: host interaction and control strategies

Abstract

Citrus is one of the most ancient fruit crops cultivated in the world. For many countries, citrus production is an important source of revenues. However, despite the richness of citrus production worldwide, fruit yields are constantly threatened by diseases that cause serious economic and social impacts to growers and consumers. One such example is citrus canker, a disease that affects all commercial citrus varieties and for which there is no cure. Currently, control measures for citrus canker are restricted to the application of copper-based compounds and the elimination of infected trees to prevent pathogen spreading in the field. However, new alternatives for the control of this disease are being developed, spanning through transgenic plants to innovative chemicals and biological control. New genome editing approaches and a repertoire of plant defense-related genes have been exploited to produce citrus lineages more tolerant to X. citri. In addition, a series of new molecules have been tested to not only inhibit X. citri growth but to also boost the plant immune system to suppress disease progression. In this review, we provide the state of art of all citrus canker control measures in use today, highlighting their utility and drawbacks and commenting on novel strategies to better control this important citrus disease.

The Arabidopsis immune receptor EFR increases resistance to the bacterial pathogens Xanthomonas and Xylella in transgenic sweet orange

“…citri and Xylella fastidiosa subsp. pauca, respectively, are important bacterial diseases and are therefore extensively studied due to their impact on citrus agribusiness (Caserta et al, 2020;Coletta-Filho et al, 2020;Martins et al, 2020). All sweet orange (Citrus sinensis) commercial varieties are susceptible to both diseases and, despite many efforts, no natural resistance has been found in C. sinensis so far.…”

GC-TOF/MS-based metabolomics analysis to investigate the changes driven by N-Acetylcysteine in the plant-pathogen Xanthomonas citri subsp. citri

“…The bacterium Xanthomonas citri subsp. citri, the causing agent of citrus canker disease, is one of the most destructive phytopathogen in the citrus agribusiness 10 . Among its virulence factors, biofilm formation plays an essential role at early stages of infection by enhancing bacterial epiphytic survival 11 – 14 .…”

TALE-induced cell death executors: an origin outside immunity?

“…This observation suggests that both N. benthamiana and lemon contain executor genes that trigger HR upon transcriptional activation of PthA4 AT . Notably, the commonly used N. benthamiana laboratory genotype is endemic to arid regions in Australia [42], which are unfavorable conditions for Xanthomonas that requires high humidity to proliferate in planta [36,43,44]. It therefore seems unlikely that the PthA4 AT -induced N. benthamiana executor gene is a product of evolutionary constraints.…”