The plant pathogenic Klebsiella pneumoniae survived in pomegranate orchard soil for more than two years in an infectious stage. The pomegranate seedlings/grafts planted at a site which had the wilt disease plant earlier and left fallow for a season also succumb to Klebsiella infection causing wilt. The bacterium also survives in root bark necrosis lesions for more than two years under laboratory storage condition.The plant pathogenic Klebsiella pneumoniae survived at a temperature up to 45˚C from a low temperature of 5˚C, indicating its surviving ability in temperate and tropical temperature condition. The survival of the bacterium at 7 to 10 pH levels indicates its tolerance to neutral and alkaline condition; however no growth of the bacterium at 2 to 6 pH indicates its intolerance to acidic condition.

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Histopathology of root bark necrosis and wilt in pomegranate incited by Klebsiella pneumoniae strain Borkar revealed that the bacterial infection was non-vascular in nature. The bacteria infect the epidermal layer and cortex of the bark tissues which are easily peeled off. Due to absence of root bark, the absorption of water and food material is hindered which results in wilting of the pomegranate plant. All other plant pathogenic bacteria inducing wilting in other plants infect the vascular system of the plant which finally leads to plant death, however the Klebsiella pneumoniae strain Borkar inciting root bark necrosis and wilt in pomegranate differed from other plant pathogenic bacteria by infecting only the cortex and epidermal cells of root bark to induce wilting in infected pomegranate plants.

Klebsiella pneumoniae causes a fatal disease in human being. The pathogen is associated with respiratory tract and lung infection responsible for respiratory mechanism. K. pneumoniae strain Borkar was also found to affect the respiratory mechanism of plant root system in Solanaceous plants. The bacterium blocks the root respiration, producing anaerobic condition and alcohol emitting foul smell in the root surrounding, which results in wilting and death of the plants (plant mortality). The symptoms of plant mortality include the wilting of affected plant seedlings and foul smell of the root system. The association of the bacterium was observed on all over the root surface but not in the root tissues. There were no changes in the root morphology or its discolouration occurred. The bacterium K.pneumoniae in human being as well as in plant seems to affect the respiratory mechanism. The wilting/death of seedlings or plants caused due to hindrance in root respiration are termed as plan mortality. The seedlings grown n soil infested with K.pneumoniae dies within a week period. In host range studies of the bacterium, out of 32 crop plants tested, only 6 were found to be susceptible to get plant mortality symptoms. These were tomato, chilli and eggplant seedlings, which showed wilting in 8 days, whereas ladies finger, green gram and horse gram showed wilting in 21, 22 and 31 days, respectively.

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