Facts about Agrobacterium tumefaciens Which statement best captures its host range and disease association?

Introduction / Context:
Agrobacterium tumefaciens is both a plant pathogen and a cornerstone of plant genetic engineering. A clear understanding of its natural host range and the disease it causes helps students connect basic pathology with biotechnology applications.

Given Data / Assumptions:

• Crown gall is the classic disease symptom associated with Agrobacterium.
• Natural susceptibility varies across plant groups.
• The question seeks the most accurate, concise statement.

Concept / Approach:
Agrobacterium induces crown galls mainly on dicotyledonous plants (e.g., rose, grapevine). While engineered methods can extend transformation to some monocots, natural infections are largely dicot-biased. Reports of gymnosperm infection are limited and not routine in nature, making the generalization inaccurate. Therefore, the best answer emphasizes crown gall disease and primary dicot host range.

Step-by-Step Solution:

Verification / Alternative check:
Plant pathology references describe classic dicot hosts (e.g., grape, stone fruits). Agricultural disease reports align with dicot susceptibility; monocot infections are rare and typically require lab intervention.

Why Other Options Are Wrong:

• Gymnosperm routine infection: not broadly supported.
• Exclusive monocot infection: opposite of observed natural host range.
• No disease: contradicted by well-documented pathology.
• Algae/fungi hosts: incorrect kingdom.

Common Pitfalls:
Confusing laboratory transformation capability with natural pathogenesis. Success in engineered monocot transformation does not imply broad natural infection.

Final Answer:
It causes crown gall disease of plants and primarily infects dicotyledonous angiosperms