<div style="text-align: justify;">Colonisation and infection of Pseudomonas syringae pv. tomato is governed not only by host resistance but also by its interactions with other phylloplane bacterial colonizers. In the present study, reduced disease symptoms were observed as a result of interaction between P. syringae pv. tomato and Klebsiella pneumoniae, a predominant human enteric pathogen colonising phyllosphere. Tomato (Solanum lycopersicum) plants raised under controlled aseptic conditions were divided into 4 groups of 25 plants each and treated as follows: Group 1- inoculated with P. syringae pv. tomato; Group 2- inoculated with K. pneumoniae; Group 3- combination of P. syringae pv. tomato and K. pneumoniae (1:1); Group 4- Distilled water (control). Sampled leaves from the above groups were analysed at 24, 48, 72 and 96 hours post inoculation for the activity of cytoplasmic Peroxidase (POX), Polyphenoloxidase (PPO) and Phenylalanine ammonia lyase (PAL). Disease incidence was recorded in treated as well as leaves emerging after 2 weeks of inoculation. Plants treated with P. syringae pv. tomato had maximum disease incidence while no infection was observed in control and those inoculated with K. pneumoniae alone. Inoculation of plants with combination of both microbes could substantially reduce the disease severity. The results thus demonstrate that K. pneumoniae, a common HEP on plant surfaces, reduces the ability of P. syringae pv. tomato to colonise the host.</div>

Effect of Klebsiella pneumoniae on speck disease development in Solanum lycopersicum