Stewart's wilt is a bacterial disease of corn caused by the bacterium Pantoea stewartii. The disease is also known as bacterial wilt or bacterial leaf blight and has been shown to be quite problematic in sweet corn. The causal organism is a facultatively anaerobic, gram-negative, rod-shaped bacterium. The disease is endemic in the mid-Atlantic and Ohio River Valley regions and in the southern portion of the Corn Belt. Stewart's Wilt causes minor reductions in field corn yield, despite common occurrence, because most hybrids grown in the Midwest have adequate resistance. However, the disease can be problematic in seed production because many countries have restrictions on maize seed from areas where the Stewart's Wilt occurs.
Dickeya dadantii is a gram-negative bacillus that belongs to the family Pectobacteriaceae. It was formerly known as Erwinia chrysanthemi but was reassigned as Dickeya dadantii in 2005. Members of this family are facultative anaerobes, able to ferment sugars to lactic acid, have nitrate reductase, but lack oxidases. Even though many clinical pathogens are part of the order Enterobacterales, most members of this family are plant pathogens. D. dadantii is a motile, nonsporing, straight rod-shaped cell with rounded ends, much like the other members of the genus, Dickeya. Cells range in size from 0.8 to 3.2 μm by 0.5 to 0.8 μm and are surrounded by numerous flagella (peritrichous).
Xylella fastidiosa is an aerobic, Gram-negative bacterium of the genus Xylella. It is a plant pathogen, that grows in the water transport tissues of plants and is transmitted exclusively by xylem sap-feeding insects such as sharpshooters and spittlebugs. Many plant diseases are due to infections of X. fastidiosa, including bacterial leaf scorch, oleander leaf scorch, coffee leaf scorch (CLS), alfalfa dwarf, phony peach disease, and the economically important Pierce's disease of grapes (PD), olive quick decline syndrome (OQDS), and citrus variegated chlorosis (CVC). While the largest outbreaks of X. fastidiosa–related diseases have occurred in the Americas and Europe, this pathogen has also been found in Taiwan, Israel, and a few other countries worldwide.
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 range of potential host plants. It is known as Granville wilt when it occurs in tobacco. Bacterial wilts of tomato, pepper, eggplant, and Irish potato caused by R. solanacearum were among the first diseases that Erwin Frink Smith proved to be caused by a bacterial pathogen. Because of its devastating lethality, R. solanacearum is now one of the more intensively studied phytopathogenic bacteria, and bacterial wilt of tomato is a model system for investigating mechanisms of pathogenesis. Ralstonia was until recently classified as Pseudomonas, with similarity in most aspects, except that it does not produce fluorescent pigment like Pseudomonas. The genomes from different strains vary from 5.5 Mb up to 6 Mb, roughly being 3.5 Mb of a chromosome and 2 Mb of a megaplasmid. While the strain GMI1000 was one of the first phytopathogenic bacteria to have its genome completed, the strain UY031 was the first R. solanacearum to have its methylome reported. Within the R. solanacearum species complex, the four major monophyletic clusters of strains are termed phylotypes, that are geographically distinct: phylotypes I-IV are found in Asia, the Americas, Africa, and Oceania, respectively.
Glomerella graminicola is an economically important crop parasite affecting both wheat and maize where it causes the plant disease Anthracnose Leaf Blight.
Xanthomonas 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 plant species. Different species typically have specific host and/or tissue range and colonization strategies.
Pantoea agglomerans is a Gram-negative bacterium that belongs to the family Erwiniaceae.
Clavibacter michiganensis is an aerobic non-sporulating Gram-positive plant pathogenic actinomycete of the genus Clavibacter. Clavibacter michiganensis has several subspecies. Clavibacter michiganensis subsp. michiganensis causes substantial economic losses worldwide by damaging tomatoes and potatoes.
Verticillium dahliae is a fungal plant pathogen. It causes verticillium wilt in many plant species, causing leaves to curl and discolor. It may cause death in some plants. Over 400 plant species are affected by Verticillium complex.
Pseudopestalotiopsis theae is a plant pathogen affecting tea.
Pseudocercospora fuligena is a fungal plant pathogen infecting tomatoes. It is the cause of the fungal disease black leaf mold. The fungus was first described in the Philippines in 1938 and has since been reported in numerous countries throughout the tropics and subtropics. It was reported in the United States in 1974, initially in Florida, and has since been reported in non-tropical regions including Ohio and North Carolina.
A wilt disease is any number of diseases that affect the vascular system of plants. Attacks by fungi, bacteria, and nematodes can cause rapid killing of plants, large tree branches or even entire trees.
Black rot, caused by the bacterium Xanthomonas campestris pv. campestris (Xcc), is considered the most important and most destructive disease of crucifers, infecting all cultivated varieties of brassicas worldwide. This disease was first described by botanist and entomologist Harrison Garman in Lexington, Kentucky, US in 1889. Since then, it has been found in nearly every country in which vegetable brassicas are commercially cultivated.
Streptomyces acidiscabies is a streptomycete bacterium species, causing a scab disease of potatoes. Its type strain is RL-110.
Verticillium nonalfalfae is a soilborne fungus in the order Hypocreales. It causes verticillium wilt in some plant species, particularly Ailanthus altissima. The fungus produces a resting mycelium characterized by brown-pigmented hyphae. It is most closely related to V. dahliae and V. alfalfae.
Phytophthora hydropathica is an oomycete plant pathogen that is found in aquatic environments such as irrigation and river water. The pathogen was previously classified as P. drechsleri Dre II before being categorized as its own distinct species. P. hydropathica has been primarily found in association with ornamental plant nurseries. The pathogen has been isolated throughout the Southern United States, as well as internationally in Mexico, Italy, and Spain.
Pecan bacterial leaf scorch is a disease of the pecan tree that is common throughout the production regions of the United States caused by the pathogenic bacterium Xylella fastidiosa subsp. multiplex. The pathogen was initially discovered to be coincidentally associated with symptoms of pecan fungal leaf scorch in 1998 and has subsequently been found to be endemic in the southeastern United States, as well as Arizona, California, and New Mexico.
Clavibacter insidiosus is a species of Clavibacter. It causes bacterial wilt, with its most notable host being Medicago sativa (alfalfa). Other species in the Medicago genus are also known to be hosts such as Medicago falcata. Additionally, Lotus corniculatus, Melilotus alba, Onobrychis viciifolia, and Trifolium sp. are known hosts.
Xanthoferrin is an α-hydroxycarboxylate-type of siderophore produced by xanthomonads. Xanthomonas spp. secrete xanthoferrin to chelate iron under low-iron conditions. The xanthoferrin siderophore mediated iron uptake supports bacterial growth under iron-restricted environment.
Epicoccum sorghinum is an ascomycete fungus with known plant pathogenicity to sugarcane and rice, causing ring spot disease and leaf spot disease. This fungus is primarily known for its production of tenuazonic acid, which leads to complications with growth and causes the symptoms of leaf spot disease. Tenuazonic acid not only affects plant growth, but has recently been proven to impact human health due to its prevalence in food and beverages. It is widely dispersed, affecting multiple hosts in different countries. Although not a serious threat, Epicoccum sorghinum has been known to influence the sorghum grain-mold complex in ways which reduce crop yields, seed viability, and kernel weight. As a result of continuous phylogenetic and morphological discoveries relevant to Epicoccum sorghinum, this fungus has undergone a number of name changes.
