Agrobacterium is responsive to phenolic compounds such as acetosyringone which are produced when the plant was wounded. On the other hand, most monocot plants did not produce the compounds or produced it in a smaller quantity, therefore resulted in the low efficiency of the Agrobacterium attachment.

Unfortunately, the capacity of Agrobacterium to infect monocots is limited to a narrow range of genotypes and the utility of the technique is further limited by the recalcitrance of many genotypes to callus formation and regeneration.

The T-DNA renders the plant cell tumorous, and also codes for enzymes involved in the synthesis of certain tumour-specific compounds called opines. tumefaciens, it is generally believed that the Ti plasmid can be used as a vector for dicotyledonous plants only1–5.

Virulent strains of the soil bacterium Agrobacterium tumefaciens infect dicotyledonous plants and elicit a profound neoplastic response which results in crown gall formation (18).

In humans. Although generally seen as an infection in plants, Agrobacterium can be responsible for opportunistic infections in humans with weakened immune systems, but has not been shown to be a primary pathogen in otherwise healthy individuals.

Agrobacterium tumefaciens causes crown gall disease on various plant species by introducing its T-DNA into the genome. Therefore, Agrobacterium has been extensively studied both as a pathogen and an important biotechnological tool.

Crown gall symptoms include round, wart-like growths — 2 inches or larger in diameter — that appear at or just above the soil line, or on lower branches and stems. Plants with several galls may be unable to move water and nutrients up the trunk and become weakened, stunted and unproductive.

Avoid planting too deep. Avoid mounding soil up on newly planted trees. Keep crown of tree as dry as possible; Agrobacterium is favored by wet environments. Do not rely on short-term fallow rotations (e.g. <2 yrs.) to control Agrobacterium tumefaciens.

Crown gall is caused by the bacterial plant pathogen, Agrobacterium tumefaciens. Crown gall bacteria enter plant roots through wounds. Wounds may have been created by planting, grafting, soil insect feeding, root damage from excavation or other forms of physical damage.

Many bacteria of this genus are known to cause a number of diseases in plants. Moreover, Agrobacterium are known for causing diseases through the use of horizontal gene transfer [5]. Tumors are the resulting symptoms produced in a wide variety of Agrobacterium caused plant diseases [5].

Genetic engineering of plants was perfected by a bacterium named Agrobacterium tumefaciens, also called A. radiobacter, long before humans invented bioengineering. The disease is called crown gall as it most often is found in the crown of plants.

Crown gall, a bacterial disease that occurs throughout the world, infects several different plant hosts. In particular, it is a devastating disease in the Rosaceae (rose) family. The specific bacterium, Agrobacterium tumefaciens, causes crown gall by inserting a tumor-inducing gene into the plant genome.

Crown gall infection is spread by movement of infested soil, by infected plant material, and via budding and grafting tools.

Artesunate and Garlic treated seedlings had better growth compared to the diseased seedlings. However, Garlic extract was observed to be more effective than Artesunate at inhibiting gall (tumor). This therefore confirmed the efficacy of garlic extracts and synthetic artesunate against crown gall disease of tomato.

: a disease that affects many species of plants and is caused by a bacterium (Agrobacterium tumefaciens) which forms tumorous enlargements usually just below the ground on the stem.

Once crown galls are exposed, removing the gall and the bark tissue surrounding the gall is the most effective treatment currently available. Treatments that kill or remove the bark surrounding the gall result in very good control. Research has shown that careful surgery is very effective.

1 : brazen boldness coupled with impudent assurance and insolence had the gall to think that he could replace her. 2a : bile especially : bile obtained from an animal and used in the arts or medicine. b : something bitter to endure. c : bitterness of spirit : rancor.

Symptoms. The disease first appears as small overgrowths or galls on the roots, crown, trunk, or canes. Galls usually develop on the crown or trunk of the plant near the soil line or underground on the roots. Above ground or aerial galls may form on canes of brambles and highly susceptible cultivars of grape.

The galls are the result of infestation by gouty oak gall wasps, a tiny insect that lays their eggs on oak leaves. It will take several years, but the galls can eventually kill trees. “The larva secrete an enzyme that cause the tree to grow a tumor around it. The gall is actually part of the tree.

Agrobacterium tumefaciens causes crown gall disease of a wide range of dicotyledonous (broad-leaved) plants, especially members of the rose family such as apple, pear, peach, cherry, almond, raspberry and roses. A separate strain, termed biovar 3, causes crown gall of grapevine.

Two known mechanisms of biological control of crown gall are antibacterial compounds produced by nonpathogenic strains11,13,31,32) and a unique mechanism associated with the quorum-sensing and caseinolytic protease (clp) systems of nonpathogenic R. vitis strain F2/5.

Crown gall is the most widely distributed bacterial disease of plants in the world, affecting over 100 species of fruit crops, and woody and herbaceous ornamentals, including rose, euonymus, lilac, poplar, viburnum, willow, apple, pear, brambles, stone fruits and grapes.

Crown gall is a disease caused by the bacterium Rhizobium radiobacter (synonym Agrobacterium tumefaciens), which enters the plant through wounds in roots or stems and stimulates the plant tissues to grow in a disorganised way, producing swollen galls. Galls are present all year.

The infectious causes are classified as biotic (living) causes of plant problems. They include (but are not limited to) insects, mites, and disease pathogens. Environmental stresses, such as temperature injury and water or nutrient stress, are abiotic (nonliving) factors that may affect plant health.

Long Answer: All living organisms die after their life span ends. Since, they are still regarded as once part of a living entity; they are BIOTIC components. Dead organisms are not abiotic. These leaves were once part of a plant or tree which was biotic.

A pond or lake ecosystem includes biotic (living) plants, animals and micro-organisms, as well as abiotic (nonliving) physical and chemical interactions. Pond and lake ecosystems are a prime example of lentic ecosystems.

Like water, oxygen (O2) is another important abiotic factor for many living organisms.

The term biotic means living or having lived. Examples of biotic factors would include a frog, a leaf, a dead tree, or a piece of wood. The term abiotic means non-living, or never having lived. Examples of abiotic factors would include gold, rock, bicycle, brick, and cement.

Mold is the fungi which is biotic. The abiotic is something which is non living but influence the living system. The mold is filamentous hyphae like fungi which is biotic in nature because it influences the living system to great extent.

Is it biotic or abiotic?

A	B
air	abiotic
fish	biotic
whale	biotic
grass	biotic