Many plant pathologists believe that plant resistance is based upon the interplay of different signaling molecules? Justified.

Yes.

Explanation:

Many plant pathologists believe that plant resistance is based upon the interplay of different signaling molecules because plants have various signaling molecules that plays a great role in their growth and development. Ethylene, auxin, cytokinins, gibberellins, and abscisic acid are the growth regulators that controls the growth of plants in different conditions i.e. in resistance. These signals leads the plant to take measures in difficult situations experience by the plants so in this way the plant is resistance to the harsh environmental condition.

that is wrong, its not thymus.