Question

Which core genes are present in the T-DNA region of the Ti plasmid of Agrobacterium tumefaciens?

• A. vir genes
• B. Opine, Auxin and Cytokinin synthesis
• C. Antibiotic resistance genes
• D. Replication origin genes

Hint:

Remember: \[ \boxed{ \begin{aligned} \text{T-DNA} &\rightarrow \text{Auxin + Cytokinin + Opine genes} \textit{vir}\text{ genes} &\rightarrow \text{Transfer of T-DNA} \end{aligned} } \]

Answer 1

The Correct Option is B

Step 1: Recall the structure of the Ti plasmid. The Ti (Tumor-inducing) plasmid contains:
• T-DNA region – transferred into the plant genome.
• vir genes – located outside the T-DNA and required for T-DNA transfer.

Step 2: Identify the genes present in T-DNA. The T-DNA region contains genes responsible for: \[ \boxed{ \begin{aligned} &\text{Auxin synthesis} &\text{Cytokinin synthesis} &\text{Opine synthesis} \end{aligned} } \] These genes induce crown gall tumor formation and opine production in infected plant cells. Therefore, \[ \boxed{(B)} \] is the correct answer.