Pseudomonas savastanoi explained

Pseudomonas savastanoi is a gram-negative plant pathogenic bacterium that infects a variety of plants. It was once considered a pathovar of Pseudomonas syringae, but following DNA-relatedness studies, it was instated as a new species.^[1] It is named after Savastano, a worker who proved between 1887 and 1898 that olive knot are caused by bacteria.^{[2] [3]}

The pathovar of greatest economical significance is Pseudomonas savastanoi pv. savastanoi, which causes the disease olive knot. Symptoms include formation of galls on infected trees; tumour formation is induced by indoleacetic acid biosynthesis by the bacteria, in a similar manner to the well-studied crown gall pathogen, Agrobacterium tumefaciens.^{[4] [5]}

History

One of the first scientists to carry out scientific and modern research on the disease of olive trees caused by Pseudomonas savastanoi (Italian: la rogna dell'ulivo) was Giuseppe Maria Giovene (1753-1837), who explained his conclusions in his publication Sulla rogna degli ulivi (1789).^[6]

Pathovars

• Pseudomonas savastanoi causes ash bacterial canker.^[7]
• Pseudomonas savastanoi attacks oleander.
• Pseudomonas savastanoi causes olive knot.^[4]
• Pseudomonas savastanoi attacks Phaseolus (bean) plants ^[8]

Quorum sensing

P. s. pv. s. has an unusual quorum sensing dynamic: It shares quorum with an entirely different order, the Enterobacterales.^[9] Hosni et al., 2011 and Caballo-Ponce et al., 2018 find P. s. pv. s. produces very similar N-acyl homoserine lactones (AHLs) to the Erwiniaceae Erwinia toletana and Pantoea agglomerans. Hosni find an avirulent mutant – defective for AHL production – is restored to virulence by the presence of E. toletana and P. agglomerans. These results demonstrate disease enhancing cooperation but also reveal a possible way that undiscovered cheating may be occurring.

External links

• Type strain of Pseudomonas savastanoi at BacDive - the Bacterial Diversity Metadatabase

Notes and References

1. Gardan . DNA relatedness among the pathovars of Pseudomonas syringae and description of Pseudomonas tremae sp. nov. and Pseudomonas cannabina sp. nov. (ex Sutic and Dowson 1959) . Int J Syst Bacteriol . 49 . 469–78 . Apr 1999 . 10319466 . Shafik . H . Belouin . S . Broch . R . Grimont . F . Grimont . PA . 10.1099/00207713-49-2-469 . 2. etal. free .
2. George M. Garrity: Bergey's Manual of Systematic Bacteriology. 2. Auflage. Springer, New York, 2005, Volume 2: The Proteobacteria, Part B: The Gammaproteobacteria
3. Joseph M. Ogawa, Harley English: Diseases of temperate zone tree fruit and nut crops
4. Hosni T, et al. 2011. Sharing of quorum-sensing signals and role of interspecies communities in a bacterial plant disease. ISME J. .
5. 16593778 . 1986 . Yamada . T . Lee . PD . Kosuge . T . Tsune Kosuge . Insertion sequence elements of Pseudomonas savastanoi: Nucleotide sequence and homology with Agrobacterium tumefaciens transfer DNA . 83 . 21 . 8263–7 . 386908 . Proceedings of the National Academy of Sciences of the United States of America . 10.1073/pnas.83.21.8263 . 1986PNAS...83.8263Y . free .
6. Book: Memoria sulla rogna degli ulivi del canonico d. Giuseppe Maria Giovene. 1 . per Vincenzo Flauto . Giovene. Giuseppe Maria. 1789.
7. Smith, Dunez, Lelliot, Phillips and Archer (1988) European Handbook of Plant Disease. Blackwell Scientific Publications.
8. B. P Borowicz, A Maćkowiak, H Pospieszny (2002) Improved identification of Pseudomonas savastanoi pv. phaseolicola at the molecular level. EPPO Bulletin 32 (3), 467–469.
9. Friesen . Maren L. . Social Evolution and Cheating in Plant Pathogens . . . 58 . 1 . 2020-08-25 . 0066-4286 . 10.1146/annurev-phyto-010820-012740 . 55–75. free .