Bacterial wilt is a complex of diseases that occur in plants such as

Cucurbitaceae The Cucurbitaceae (), also called cucurbits or the gourd family, are a plant family (biology), family consisting of about 965 species in 101 genera.

Solanaceae Solanaceae (), commonly known as the nightshades, is a family of flowering plants in the order Solanales. It contains approximately 2,700 species, several of which are used as agricultural crops, medicinal plants, and ornamental plants. Many me ...

(

tomato The tomato (, ), ''Solanum lycopersicum'', is a plant whose fruit is an edible Berry (botany), berry that is eaten as a vegetable. The tomato is a member of the nightshade family that includes tobacco, potato, and chili peppers. It originate ...

etc.) and are caused by the pathogens ''Erwinia tracheiphila'', a

gram-negative Gram-negative bacteria are bacteria that, unlike gram-positive bacteria, do not retain the crystal violet stain used in the Gram staining method of bacterial differentiation. Their defining characteristic is that their cell envelope consists ...

bacterium, or '' Curtobacterium flaccumfaciens pv. flaccumfaciens'', a

gram-positive In bacteriology, gram-positive bacteria are bacteria that give a positive result in the Gram stain test, which is traditionally used to quickly classify bacteria into two broad categories according to their type of cell wall. The Gram stain is ...

bacterium.

Cucumber The cucumber (''Cucumis sativus'') is a widely-cultivated creeping vine plant in the family Cucurbitaceae that bears cylindrical to spherical fruits, which are used as culinary vegetables.melon A melon is any of various plants of the family Cucurbitaceae with sweet, edible, and fleshy fruit. It can also specifically refer to ''Cucumis melo'', commonly known as the "true melon" or simply "melon". The term "melon" can apply to both the p ...

plants are most susceptible, but squash,

pumpkin A pumpkin is a cultivar, cultivated winter squash in the genus ''Cucurbita''. The term is most commonly applied to round, orange-colored squash varieties, but does not possess a scientific definition. It may be used in reference to many dif ...

s, and

gourd Gourds include the fruits of some flowering plant species in the family Cucurbitaceae, particularly '' Cucurbita'' and '' Lagenaria''. The term refers to a number of species and subspecies, many with hard shells, and some without. Many gourds ha ...

s may also become infected. Bacterial wilts of tomato, ''

Capsicum ''Capsicum'' () is a genus of flowering plants in the Solanum, nightshade family Solanaceae, native to the Americas, cultivated worldwide for their edible fruit, which are generally known as "peppers" or "capsicum". Chili peppers grow on five s ...

'' (pepper), '' Solanum ovigerum'' (eggplant), and

potato The potato () is a starchy tuberous vegetable native to the Americas that is consumed as a staple food in many parts of the world. Potatoes are underground stem tubers of the plant ''Solanum tuberosum'', a perennial in the nightshade famil ...

can be caused by ( Burkholderiaceae) '' Ralstonia solanacearum''. Other bacteria in the family Burkholderiaceae can cause bacterial wilt of carnation. Bacteria in the genus ''

Xanthomonas ''Xanthomonas'' (from greek: ''xanthos'' – "yellow"; ''monas'' – "entity") is a genus of bacteria, many of which cause plant pathology, plant diseases. There are at least 27 plant associated ''Xanthomonas spp.'', that all together infect at l ...

'' can cause banana bacterial wilt or bacterial wilt in the genus ''

Agrostis ''Agrostis'' (bent or bentgrass) is a large and very nearly Cosmopolitan distribution, cosmopolitan genus of plants in the Poaceae, grass family, found in nearly all the countries in the world. It has been bred as a Genetically modified organis ...

''.

Disease transmission

''Erwinia tracheiphila'' is spread between plants by two species of insect vectors, striped cucumber beetles (''Acalymma vittatum'') and spotted cucumber beetles (''Diabrotica undecimpunctata''). The beetles acquire ''E. tracheiphila'' by feeding on infected plants, then carry the bacteria in their digestive tracts. The disease may be spread to susceptible plants through feeding wounds, by way of infected mouthparts or frass. The bacteria is capable of overwintering in the gut of its insect vectors.

Symptoms and diagnosis

Bacterial wilt is a disease of the

vascular tissue Vascular tissue is a complex transporting tissue, formed of more than one cell type, found in vascular plants. The primary components of vascular tissue are the xylem and phloem. These two tissues transport fluid and nutrients internally. T ...

. When a plant is infected, ''E. tracheiphila'' multiplies within the

xylem Xylem is one of the two types of transport tissue (biology), tissue in vascular plants, the other being phloem; both of these are part of the vascular bundle. The basic function of the xylem is to transport water upward from the roots to parts o ...

, eventually causing mechanical blockage of the water transport system. The first sign of infection, which appears about five days after acquisition, is the wilting of individual leaves on a single stem. However, the disease will soon spread down the runner and then infect the whole plant, causing it to shrivel and die. There is a diagnostic test for bacterial wilt that can be done in the field. The presence of the ''E. tracheiphila'' causes the sap to become a milky color and acquire a sticky consistency. If the stem is cut near the crown and the ends are slowly pulled apart, the sap should form a viscous string.

Treatment and prevention

Once a plant is infected, there is no way of stopping the spread of the disease. Some cucurbit cultivars are less susceptible than others, so it is beneficial to plant these cultivars. However, since wilt-resistant plants have not yet been developed, the most effective way to prevent the disease is to keep beetle populations at a minimum. While various methods of beetle control have been tested, the most effective preventative measure is to keep beetle populations as low as possible through careful field monitoring and

insecticide Insecticides are pesticides used to kill insects. They include ovicides and larvicides used against insect eggs and larvae, respectively. The major use of insecticides is in agriculture, but they are also used in home and garden settings, i ...

sprays. Cultural control can also be effective, thus this means one should apply the direct methods.

References

General references

"Bacterial Wilt"
b
APSnet

by Cornell University Plant Disease Clinic * Yao, C., Geoffrey, Z., Bauske, E., and Kloepper, J. 1996. ''Relationship Between Cucumber Beetle Density and Incidence of Bacterial Wilt of Cucurbits.'' Entomological Society of America 89: 510–514.

External links

Type strain of ''Erwinia tracheiphila'' at Bac''Dive'' - the Bacterial Diversity Metadatabase

Brave new world: recent evolution of an insect-transmitted pathogen
a seminar given by Dr. Roberto Kolter on May 17, 2017, at the US NIH. * * * * {{Taxonbar, from=Q4840003 Bacterial plant pathogens and diseases Eudicot diseases Enterobacterales