Crown gall is a plant disease caused by a bacterium named Agrobacterium tumefaciens. The word "crown gall" is spelled using the International Phonetic Alphabet (IPA) as /kraʊn ɡɔːl/. The first syllable "crown" is pronounced with a diphthong, which makes the vowel sound glide from the "ow" to the "n" sound. The second syllable "gall" begins with the "g" sound and ends with the "l" sound, making it a plosive consonant. Understanding the correct spelling and pronunciation of the word is essential in the field of agriculture, horticulture and botany.
Crown gall, also known as plant gall, is a term used to describe a plant disease caused by the bacterium Agrobacterium tumefaciens. It is characterized by the development of abnormal growths or swellings, known as galls, on various parts of the plant, but particularly near the base of the stem and crown. These galls are typically round and can vary in size and color, depending on the plant species and cultivar.
Crown gall can affect a wide range of woody and herbaceous plants, including but not limited to fruit trees, grapevines, roses, and ornamental plants. The disease is often introduced into the plant through wounds or cuts, which provide an entry point for the bacteria. Once inside the plant, A. tumefaciens transfers a portion of its DNA, known as the Ti (tumor-inducing) plasmid, into the host plant's cells. This leads to the production of plant hormones, such as auxins and cytokinins, which stimulate abnormal cell division and growth, resulting in the formation of galls.
The galls can have various impacts on the affected plants. They may disrupt the flow of water and nutrients, hinder plant development, weaken the plant's immune system, and even lead to stunted growth, reduced yield, and eventual plant death in severe cases.
Preventing crown gall involves implementing sound horticultural practices, such as proper pruning techniques, reducing plant stress, and avoiding excessive soil moisture. There are also some cultural control methods and chemical treatments available for managing crown gall, although their effectiveness can vary depending on the plant species, the severity of the disease, and other factors.
The word "crown gall" is a combination of two separate words – "crown" and "gall", each with their own etymology.
- "Crown" originates from the Old English word "cran" (or "cron") meaning "top of the head" or "coronet". It is related to the Latin word "corona", meaning "crown" or "garland". Over time, the term "crown" has come to represent a regal headdress symbolizing authority, power, and prestige.
- "Gall" comes from the Old English word "gealla", which means "sore" or "excrescence". This, in turn, is derived from the Old Norse word "gall", meaning "growth" or "swelling".