Bacterial inflorescence rot of grapevine caused by Pseudomonas syringae pv. syringae

Melanie Weckert, Ella Zaplin, Suzy Rogiers, Leonard Quirk, Andrew Clark, C. X. Huang

Research output: Contribution to journalArticlepeer-review

19 Citations (Scopus)


Molecular sequencing (rpoB) and standard pathological and microbiological methods identified Pseudomonas syringae pv. syringae (Pss) as the causal agent of bacterial inflorescence rot of grapevines (Vitis vinifera) in three vineyards in Tumbarumba, NSW, Australia in 2006 and 2007. Pss strains from shrivelled berries and necrotic inflorescences of diseased grapevines were used to inoculate leaves and inflorescences of potted cv. Semillon grapevines. Pss caused disease symptoms similar to those experienced in the field, including angular leaf lesions, longitudinal lesions in shoot tissues and rotting of inflorescences from before flowering until shortly after fruit set. High humidity promoted symptom severity. The necrotic bunch stem and leaf lesions were susceptible to the development of Botrytis cinerea infections. Cryo-scanning electron microscopy (cryoSEM) indicated that Pss entered leaves and inflorescence tissues via distorted, open, raised stomata surrounded by folds of tissue that appeared as 'star-shapedï'½ callose-rich complexes when viewed by UV light microscopy. In necrotic tissues, cryoSEM revealed Pss within petiole parenchyma cells and air-filled rachis xylem vessels. This is the first report of inflorescence and hence fruit loss caused by Pss in grapevines. The disease is described as 'bacterial inflorescence rotï'½ and regarded as one that expands the previously reported pathology of grapevines caused by P. syringae. This study also indicated that infection by Pss might promote destructive B. cinerea infections when the fungus is already present but latent, although further experimentation is needed to prove such an interaction.
Original languageEnglish
Pages (from-to)325-337
Number of pages13
JournalPlant Pathology
Issue number2
Early online date2010
Publication statusPublished - Apr 2011


Dive into the research topics of 'Bacterial inflorescence rot of grapevine caused by Pseudomonas syringae pv. syringae'. Together they form a unique fingerprint.

Cite this