Sir Jagadish Chunder Bose, an Indian physicist credited with the first wireless detection devices and the discovery of millimetre length electromagnetic waves is also recognized for his pioneering research in biophysics. His research into plant stimuli showed that plants responded to various stimuli as if they had nervous systems like animals. Bose demonstrated the electrical nature of conduction in various stimuli in plants. This was later proven by Wildon et al in Nature (1992, 360, 62-65.) Bose also claimed that plants could feel and understand affection/torture due to difference in vibrations plants are subjected to.
Books:
Life Movements in Plants (1918)
The Nervous Mechanism of Plants (1926)
The Physiology of the Ascent of Sap (1923)
Plant Response as a means of Physiological Investigation (1906)
Researches on the Irritability of Plants (1913)
Response in the Living and Non-Living (1902)
Sir Jagadis Chunder Bose