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ARS Home » Pacific West Area » Parlier, California » San Joaquin Valley Agricultural Sciences Center » Crop Diseases, Pests and Genetics Research » Research » Publications at this Location » Publication #407033

Research Project: Development of Applied Management Systems for Diseases of Perennial Crops with Emphasis on Vector-Borne Pathogens of Grapevine and Citrus

Location: Crop Diseases, Pests and Genetics Research

Title: Fatty acid methyl ester profiling of Californian Xylella fastidiosa strains

item Wallis, Christopher
item Chen, Jianchi

Submitted to: PhytoFrontiers
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/19/2023
Publication Date: 2/26/2024
Citation: Wallis, C.M., Chen, J. 2024. Fatty acid methyl ester profiling of Californian Xylella fastidiosa strains. PhytoFrontiers. 10(10).

Interpretive Summary: Xylella fastidiosa (Xf) is a xylem-limited bacterium that infects hundreds of plant species, but only a few strains of the bacteria from different subspecies can cause disease in plants. For instance, strains of Xylella fastidiosa subspecies fastidiosa (Xff) can cause Pierce’s disease of grapevine and strains in the Xylella fastidiosa spp. multiplex (Xfm) are relatively benign. Methods to accurately differentiate pathogenic from non-pathogenic strains are needed to improve disease management. Analysis of fatty acid profiles from the outer membrane of Xf was performed to examine differences between strains and subspecies. Xff fatty acid profiles were distinct to those of Xfm. These differences could account for, in part, the ability of Xff to be pathogenic. Diagnostic techniques also could be developed using fatty acid profiles to identify unknown Xylella isolates to subspecies.

Technical Abstract: Xylella fastidiosa ssp. fastidiosa (Xff) is the causal agent of Pierce’s disease of grapevine, a management-intensive and potentially deadly disease. However, different stains and other subspecies, such as Xylella fastidiosa ssp. multiplex (Xfm), exist in the same regions and vary in capacity to cause disease. All strains differ in the fatty acids that comprise cell membranes, as these would allow adaptations to specific host microenvironments. Therefore, studies were initiated to observe the fatty acid profiles of different Californian Xf isolates via fatty acid methyl ester (FAME) analysis. Observations revealed that Xff strains had similar FAME profiles that were distinct from those of Xfm, even in isolates that originated from the same host plant species. These data show consistent differences between Xff and Xfm strains, and demonstrate the potential that FAME profiling has for Xylella subspecies identification of novel isolates.