Mutations in plant cells can be induced by :

Mutations in plant cells are changes in the DNA sequence that can arise when the genetic material is damaged or altered.

Among the listed agents, gamma rays are a form of high‑energy ionizing radiation. Their photons have enough energy to ionize atoms and break chemical bonds, including the covalent bonds that hold the two strands of DNA together.

When gamma rays strike a plant cell, they can cause:

• Single‑strand breaks (SSBs) in the DNA.
• Double‑strand breaks (DSBs), which are especially detrimental because they are harder for the cell to repair correctly.
• Base modifications (e.g., oxidation of nucleobases) and cross‑linking of DNA with proteins.

The cellular repair mechanisms may incorrectly rejoin the broken ends or misincorporate nucleotides, leading to permanent alterations in the genetic code—i.e., mutations.

In contrast, the other options do not have mutagenic properties:

• Zeatin and Kinetin are cytokinins, plant hormones that regulate cell division and growth but do not damage DNA.
• Infrared rays are low‑energy, non‑ionizing radiation; they primarily affect thermal processes and lack the ability to ionize atoms or break DNA bonds.

Therefore, the only agent from the list capable of inducing mutations in plant cells is gamma rays.