Molecular signatures between citrus and Candidatus Liberibacter asiaticus

Abstract

Citrus Huanglongbing (HLB), also known as citrus greening, is one of the most devastating citrus diseases worldwide. Candidatus Liberibacter asiaticus (CLas) is the most prevalent strain associated with HLB, which is yet to be cultured in vitro. None of the commercial citrus cultivars are resistant to HLB. The pathosystem of Ca. Liberibacter is complex and remains a mystery. In this review, we focus on the recent progress in genomic research on the pathogen, the interaction of host and CLas, and the influence of CLas infection on the transcripts, proteins, and metabolism of the host. We have also focused on the identification of candidate genes for CLas pathogenicity or the improvements of HLB tolerance in citrus. In the end, we propose potentially promising areas for mechanistic studies of CLas pathogenicity, defense regulators, and genetic improvement for HLB tolerance/resistance in the future.

Diaphorin, a polyketide produced by a bacterial symbiont of the Asian citrus psyllid, inhibits the growth of Bacillus subtilis but promotes the growth of Escherichia coli

“…Thus, this bacterial lineage can be beneficial for psyllid vectors in some ecological contexts. As with cases in other hemipteran insects (60–71), recent studies are revealing that not only interactions between host psyllids and symbiotic microbes, including those associated with the bacteriome, facultative symbionts, and plant pathogens (19–23, 29), but also interactions among such bacterial populations are important for psyllid biology and host plant pathology (11, 12, 22, 31, 35, 72). Interestingly, all the above-mentioned symbionts in D. citri , namely, Carsonella, Profftella, Wolbachia , and Liberibacter , belong to the phylum Proteobacteria and are closely related to E. coli , on which diaphorin exhibited positive effects.…”

“…Liberibacter spp. (Alphaproteobacteria: Rhizobiales), the causative agents of the citrus greening disease, HLB (9)(10)(11)(12)57). Although…”

“…The Asian citrus psyllid Diaphorina citri Kuwayama (Hemiptera: Sternorrhyncha: Psylloidea: Psyllidae) is an important agricultural pest that transmits Candidatus Liberibacter spp. (Alphaproteobacteria: Rhizobiales), the causative agents of a devastating citrus disease known as huanglongbing (HLB) or greening disease (9)(10)(11)(12). Because HLB is currently incurable, controlling D. citri is presently the most crucial part of HLB management (9,12).…”

Diaphorin, a Polyketide Produced by a Bacterial Symbiont of the Asian Citrus Psyllid, Inhibits the Growth and Cell Division of Bacillus subtilis but Promotes the Growth and Metabolic Activity of Escherichia coli

“…Thus, this bacterial lineage can also be beneficial for psyllid vectors in some ecological contexts. As with cases in other hemipteran insects ( 44 – 57 ), recent studies are revealing that not only interactions between host psyllids and symbiotic microbes, including those associated with the bacteriome, facultative symbionts, and plant pathogens ( 19 – 23 , 29 ), but also interactions among such bacterial populations are important for psyllid biology and host plant pathology ( 11 , 12 , 22 , 31 , 58 , 59 ). Interestingly, all the above-mentioned symbionts in D. citri , namely, “ Ca .…”

Biological Features and In Planta Transcriptomic Analyses of a Microviridae Phage (CLasMV1) in “Candidatus Liberibacter asiaticus”

“…The discovery of CLas phages/prophages has opened a new venue for CLas biology research. In particular, the prophage, an integrated form of phage genome in the CLas genome, has played critical roles in the genomic evolution, pathogenicity, adaptability and survival of CLas [ 8 , 12 , 13 , 14 , 15 , 16 , 17 ]. A peroxidase gene (SC2_gp095) encoded by Type 2 prophage (SC2) was found to be involved in the fitness and survival of CLas in the host plant by the suppression of the reactive oxygen-mediated host defenses [ 13 ].…”