[citation needed] Examples of susceptible hosts include petunia, pansy, poinsettia, tobacco, cotton, carrot, lettuce, tomato, and others.

[citation needed] Common symptoms include chlorotic lower foliage, yellowing of plant, stunting or wilting, and black lesions along the roots.

[citation needed] The black lesions that appear along the roots are a result of the formation of chlamydospores, resting spores of the fungus that contribute to its pathogenicity.

There are also cultural conditions which may induce stress on the host plants that favor the pathogen including high soluble salts, excessive nitrogen fertilizer, low organic matter, etc.

[citation needed] Thielaviopsis basicola is a soilborne fungus that belongs to the Ascomycota division of the "true fungi" and is a hemibiotrophic parasite.

[6] However, it is important to note that this association between vector and soilborne fungi has only been observed in commercial agricultural settings in which artificially controlled environments (i.e. greenhouses) promote conditions that deviate from the natural world.

[10] Systemic acquired resistance (SAR) is employed by the host to actively address localized infection and initiate defense signaling cascades throughout the plant.

For example, the SAR NPR1 (AtNPR1) gene is of special importance and acts to suppress the infection faculties of Thielaviopsis basicola, effectively imparting resistance to some host plants.

In order to digest and metabolize nutritive compounds from a necrotic host plant, Thielaviopsis basicola secretes enzymes such as xylanase and other hemicellulases, which break down cell tissues making them available to the fungus.

[12] During this stage, the pathogen also produces its asexual spores in the lesions to reproduce and disseminate more propagules for continued survival in the soil.

[4] The pathogen is known to stunt or delay maturity in the species it parasitizes, which, coupled with environmental limitations, can lead to severe economic losses.

[14] It has been observed that black root rot can delay plant maturity for up to a month and result in over a 40% yield reduction in the affected crop.

In fact, surveys taken in 2010 and 2011 of Australian agriculture statistics reported black root rot to be present in 93% of farms and 83% of fields studied.

[16] In addition to cotton, carrot, lupin, cabbage, clover, and tobacco are all crops cultivated in many different countries that suffer from black root rot.

[20] Despite faltering, once the use of soil mixes was traded for soilless alternatives throughout the floriculture industry, black root rot was no longer a threat to poinsettias.

[20] Thielaviopsis basicola (black root rot) has been and will remain a significant threat to crops grown globally in both agricultural and horticultural systems.

[24] Furthermore, "to avoid contamination of plants and potting media, greenhouse floors and walkways should be lightly misted with water to cut down on airborne dust transmission of T. basicola during cleaning operations".

[25] At the end of the "growing season, doing a thorough clean-up of the greenhouse can be beneficial because it reduces the possibility of the fungus surviving as a resistant chlamydospores on the soil floor and in wooden benches".

[26] Following localized infection and the influx of associated pathogen stimulants, the aforementioned immune system responses trigger systemic acquired resistance (SAR), which sets off a cascade of defense signaling throughout the plant to initiate defense strategies at distal locations targeted to attack any recognized foreign pathogens.

[7] Interestingly, in Australia, researchers have identified diploid cotton species displaying marked resistance against black root rot, yet cross-breeding these traits into viable commercial crops has proven to be difficult.

Transgenic methods of disease management offer promising new avenues scientists can take to aid in adapting plants to increasingly virulent pathogens.

[29] This phenomenon was analyzed in research conducted by German scientists who studied the transcript expression of defense related genes in Petunia hybrida when they were exposed to Thielaviopsis basicola and also colonized by arbuscular mycorrhizal fungal networks in their rhizosphere.