Recent advances in the molecular biology ofLeifsonia xylisubsp.xyli, causal organism of ratoon stunting disease

Abstract

Abstract. Twelve years ago our understanding of ratoon stunting disease (RSD) was confined almost exclusively to diagnosis of the disease and control via farm hygiene, with little understanding of the biology of the interaction between the causal agent (Leifsonia xyli subsp. xyli) and the host plant sugarcane (Saccharum spp. hybrids). Since then, research has focused on developing the molecular tools to dissect L. xyli subsp. xyli, so that better control strategies can be developed to prevent losses from RSD. Within this review, we give a brief overview of the progression in research on L. xyli subsp. xyli and highlight future challenges. After a brief historical background on RSD, we discuss the development of molecular tools such as transformation and transposon mutagenesis and discuss the apparent lack of genetic diversity within the L. xyli subsp. xyli world population. We go on to discuss the sequencing of the genome of L. xyli subsp. xyli, describe the key findings and suggest some future research based on known deficiencies that will capitalise on this tremendous knowledge base to which we now have access.

Comparative genomics of Clavibacter michiganensis subspecies, pathogens of important agricultural crops

“…Latent systemic infections of the xylem can be caused by all subspecies. All subspecies have been reported to invade seeds, and seems to poorly survive in soil [4,5]. In addition, they may have an epiphytic saprobic mode [6].…”

Genome of the Actinomycete Plant Pathogen Clavibacter michiganensis subsp. sepedonicus Suggests Recent Niche Adaptation

“…Consequently, there is a clear disparity between the amount of scientific research on plant-pathogenic coryneform bacteria and the amount of scientific research on their gramnegative counterparts. Recent advances in this field have coincided with the availability of transformation systems and complete genome sequences for representatives of the genera Clavibacter and Leifsonia, two of the major coryneform plant-pathogenic genera (14,32,48,56,74). Importantly, these advances allowed breakthrough identification of a novel set of pathogenicity-related genes in the tomato pathogen Clavibacter michiganensis subsp.…”

Cultivation of Fastidious Bacteria by Viability Staining and Micromanipulation in a Soil Substrate Membrane System

“…While Actinobacteria are well represented by pure cultures, there is a great diversity of undescribed species within this phylum in Australian arid soils, warranting further investigation (18). Of particular interest was Leifsonia xyli (mCFU65), a slow-growing, small coryneform and gram-positive phytopathogen thought to be widespread in the environment but which had, until these experiments, never been directly isolated outside the host cell (6,7,31). The remaining isolates were most similar to bacteria within the Proteobacteria, including mCFU17, a putative novel species most similar to Novosphingobium subterraneum (Table 1).…”