Lipopolysaccharide O-antigen delays plant innate immune recognition of Xylella fastidiosa

• Published in: Nature communications 2018-01, Vol.9 (1), p.390-12, Article 390
• Main Authors: Rapicavoli, Jeannette N., Blanco-Ulate, Barbara, Muszyński, Artur, Figueroa-Balderas, Rosa, Morales-Cruz, Abraham, Azadi, Parastoo, Dobruchowska, Justyna M., Castro, Claudia, Cantu, Dario, Roper, M. Caroline
• Format: Article
• Language: English
• Subjects: 38/91; 60 APPLIED LIFE SCIENCES; 631/326/421; 631/449/2169/2674; Antigens; Bacteria; Gene Expression Profiling; Gene Expression Regulation, Plant - immunology; Host plants; Host-Pathogen Interactions - immunology; Humanities and Social Sciences; Immunity; Immunity, Innate - genetics; Immunity, Innate - immunology; Immunological tolerance; Innate immunity; Lipopolysaccharides; Lipopolysaccharides - immunology; Lipopolysaccharides - metabolism; multidisciplinary; O Antigens - immunology; O Antigens - metabolism; Plant Diseases - genetics; Plant Diseases - immunology; Plant Diseases - microbiology; Plant Immunity - genetics; Plant Immunity - immunology; Plant tissues; Pretreatment; Recognition; Science; Science (multidisciplinary); Spatial discrimination; Vitis - genetics; Vitis - immunology; Vitis - microbiology; Xylella - immunology; Xylella - metabolism; Xylella - physiology; Xylella fastidiosa; Xylem
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-018-02861-5

Lipopolysaccharides (LPS) are among the known pathogen-associated molecular patterns (PAMPs). LPSs are potent elicitors of PAMP-triggered immunity (PTI), and bacteria have evolved intricate mechanisms to dampen PTI. Here we demonstrate that Xylella fastidiosa ( Xf ), a hemibiotrophic plant pathogenic bacterium, possesses a long chain O-antigen that enables it to delay initial plant recognition, thereby allowing it to effectively skirt initial elicitation of innate immunity and establish itself in the host. Lack of the O-antigen modifies plant perception of Xf and enables elicitation of hallmarks of PTI, such as ROS production specifically in the plant xylem tissue compartment, a tissue not traditionally considered a spatial location of PTI. To explore translational applications of our findings, we demonstrate that pre-treatment of plants with Xf LPS primes grapevine defenses to confer tolerance to Xf challenge. Many pathogenic bacteria have evolved to subvert host immune responses triggered by lipopolysaccharides (LPS). Here the authors show that a long terminal polysaccharide chain, known as the O-antigen, present in LPS from the plant pathogen Xylella fastidiosa can delay recognition by grapevine hosts.