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 consisting of about 965 species in around 95 genera, of which the most important to humans are: *''Cucurbita'' – squash, pumpkin, zucchini, some gourds *'' Lagen ...

and

Solanaceae The Solanaceae , or nightshades, are a family of flowering plants that ranges from annual and perennial herbs to vines, lianas, epiphytes, shrubs, and trees, and includes a number of agricultural crops, medicinal plants, spices, weeds, and orn ...

(

tomato The tomato is the edible berry of the plant ''Solanum lycopersicum'', commonly known as the tomato plant. The species originated in western South America, Mexico, and Central America. The Mexican Nahuatl word gave rise to the Spanish word ...

common bean ''Phaseolus vulgaris'', the common bean, is a herbaceous annual plant grown worldwide for its edible dry seeds or green bean, green, unripe pods. Its leaf is also occasionally used as a Leaf vegetable, vegetable and the straw as fodder. Its Pla ...

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

gram-negative Gram-negative bacteria are bacteria that do not retain the crystal violet stain used in the Gram staining method of bacterial differentiation. They are characterized by their cell envelopes, which are composed of a thin peptidoglycan cell wall ...

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. Gram-positive bacte ...

bacterium.

Cucumber Cucumber (''Cucumis sativus'') is a widely-cultivated Vine#Horticultural climbing plants, creeping vine plant in the Cucurbitaceae family that bears usually cylindrical Fruit, fruits, which are used as culinary vegetables.

and

muskmelon ''Cucumis melo'', also known as melon, is a species of '' Cucumis'' that has been developed into many cultivated varieties. The fruit is a pepo. The flesh is either sweet or bland, with or without a musky aroma, and the rind can be smooth (such a ...

plants are most susceptible, but

squash Squash may refer to: Sports * Squash (sport), the high-speed racquet sport also known as squash racquets * Squash (professional wrestling), an extremely one-sided match in professional wrestling * Squash tennis, a game similar to squash but pla ...

, pumpkins, 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. One of the earli ...

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 Americas, the Americas, cultivated worldwide for their chili pepper or bell pepper fruit. Etymology and names The generic name may come f ...

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

Irish potato The potato is a starch#Food, starchy food, a tuber of the plant ''Solanum tuberosum'' and is a root vegetable native to the Americas. The plant is a perennial plant, perennial in the nightshade family Solanaceae. Wild potato species can be fo ...

can be caused by (

Burkholderiaceae The Burkholderiaceae are a family of bacteria included in the order Burkholderiales.Garrity, George M.; Brenner, Don J.; Krieg, Noel R.; Staley, James T. (eds.) (2005). Bergey's Manual of Systematic Bacteriology, Volume Two: The Proteobacteria, ...

) ''

Ralstonia solanacearum ''Ralstonia solanacearum'' is an aerobic non-spore-forming, Gram-negative, plant pathogenic bacterium. ''R. solanacearum'' is soil-borne and motile with a polar flagellar tuft. It colonises the xylem, causing bacterial wilt in a very wide rang ...

''. 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 diseases. There are at least 27 plant associated ''Xanthomonas spp.'', that all together infect at least 400 ...

'' can cause

banana bacterial wilt Banana Xanthomonas Wilt (BXW), or banana bacterial wilt (BBW) or enset wilt is a bacterial disease caused by ''Xanthomonas campestris'' pv. ''musacearum''. After being originally identified on a close relative of banana, ''Ensete ventricosum'', i ...

or bacterial wilt in the genus '' Agrostis''.

Disease transmission

''Erwinia tracheiphila'' is spread between plants by two species of insect vectors,

striped cucumber beetle ''Acalymma vittatum'', the striped cucumber beetle, is a beetle of the family Chrysomelidae and a serious pest of cucurbit crops in both larval and adult stages. It is distributed from eastern North America to the Rocky Mountains. It is replaced ...

s (''Acalymma vittatum'') and

spotted cucumber beetle ''Diabrotica undecimpunctata'', the spotted cucumber beetle or southern corn rootworm, is a species of cucumber beetle that is native to North America. The species can be a major agricultural pest insect in North America. Spotted cucumber beetl ...

s (''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 Frass refers loosely to the more or less solid excreta of insects, and to certain other related matter. Definition and etymology ''Frass'' is an informal term and accordingly it is variously used and variously defined. It is derived from the ...

. 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 conducting 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. There ...

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

xylem Xylem is one of the two types of transport tissue in vascular plants, the other being phloem. The basic function of xylem is to transport water from roots to stems and leaves, but it also transports nutrients. The word ''xylem'' is derived from ...

, 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 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