Most studies now are with cell cultures and grafted plants, not with natural crown galls found mainly at the crown base.
The Never of Agrobacterium tumefaciens-induced crown galls on tomato stems.
Key discoveries in the history of research on crown galls
The production of crown gall tumors in plants caused by Agrobacterium tumefaciens represents a unique disease involving the transfer of DNA from the bacterium to the nucleus of the plant.
Crown gall tumors vary considerably in their morphology, ranging from recognizable stem or root tissue to a chaotic mixture of cell types (Drummond, 1979).
Whether manifested in burls sprouting from the trunks or roots of trees; tumorous growths like the crown galls responsible for plant diseases; kernels; warts; beer bellies; swollen glands; lumps both benign and malignant; or lobes characteristic of cauliflower, squash, and the brain, nature abounds in protrusions: sometimes curved outward, sometimes resembling pouches or simply bulges (the latter word derivative from the Latin bulga, or bag).
Hard and "woody," burls differ from crown galls, destructive growths found at the soil line or root level, which have been described as "punky" or rotting; crown gall bacteria from the soil can enter a plant through wounds caused by such innocuously "suburban" implements as lawn mowers ...
Crown gall disease is one of the most economically important soil-borne bacterial plant diseases around the world.
Grapevine crown gall, as one of the most important diseases of grapevine around the world, (2,3) is caused mainly by Rhizobium vitis (Ti) [= Agrobacterium vitis (Ti), A.
However, in the case of grapevines, wounding events such as freezing injuries are often associated with an outbreak of crown gall because exposed wounded tissues are more susceptible to infection by R.
Crown gall infection takes place not only in vineyards but also in nurseries.
The most serious problems we face are that there are no effective control methods against grapevine crown gall. The nonpathogenic R.