Agrobacterium tumefaciens is often used in the production of transgenic plants because of its ti plasmid. this plasmid is usually "disarmed" by deleting its tumor genes along with the genes for producing
what products that would have been advantageous to the bacterium?

Opines

Explanation:

Agrobacterium tumefaciens  is a rod shaped Gram-negative soil bacterium belonging to the family Rhizobiaceae. The organism harbors a tumor-inducing plasmid (T-DNA) of about 200kbp. It is a pathogen of walnuts, sugar beets, horse radish and others. It has the ability to transfer its tumor-inducing plasmid ( extra chromosomal DNA capable of replicating itself) through a t-pilus with the aid of vir proteins to the host. The plasmid encode for genes responsible for the production of Auxins and Cytokinnins on T-DNA through a pathway called IAM exclusively controlled by the bacterium since plant don't use the pathway and therefore leads to efficient production of Auxins  and Cytokinnins which leads to tumor formation and cell proliferation.

Also present on the plasmid is the code encoding for enzymes that catalyses production of specialized amino acids called opines which the organism use for nitrogen source. Many organisms do not use the amino acid, when deleting this tumor genes the codes for the enzyme is also deleted from the T-DNA  and the organism is not able to initiate the synthesis of this amino acid.  

d. changes in climate and historical records

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