By Ritambhara
Jagadish Chandra Bose spent the second half of his career measuring electrical responses in plants. The Calcutta physicist argued that plants react to the world through the same electrical processes that run through animal muscle and nerve.
Bose was born in Mymensingh, in present-day Bangladesh, on 30 November 1858. He first made his name in the 1890s with experiments on very short radio waves. Around 1900 he turned to plants. He published Response in the Living and Non-Living in London in 1902, and he dedicated the Bose Institute in Calcutta on his birthday, 30 November 1917. He died at Giridih on 23 November 1937.
He made plants write their own records
Bose built instruments that turned slow, tiny plant movements into traced records. His crescograph magnified growth by up to ten million times, according to Banglapedia and the Dictionary of Scientific Biography. He worked on the touch-sensitive Mimosa pudica, the telegraph plant Desmodium, and ordinary crops such as carrot and radish. In Plant Autographs and Their Revelations (1927) he called the plant, once wired to his recorders, “the most eloquent chronicler of its inner life and experiences”.
He tested plants with heat, poison and anaesthetic
His method was consistent. He applied a stimulus and recorded the electrical and mechanical response. The biophysicist V. A. Shepherd, reviewing his papers in Science and Culture in 2012, lists the agents he used. They included cyanide, copper sulphate, sudden changes of temperature, chloroform and ether. Each one blocked the folding of Mimosa leaves or stopped the rhythmic pulsing of Desmodium leaflets. Chloroform also halted the rise of sap in his tree experiments. Bose concluded that an electrical impulse travelled through the phloem and made the leaf collapse.
London rejected the work and later science confirmed much of it
Bose presented his plant results at the Royal Institution in May 1901 to an audience of more than 350 scientists. The physiologist John Burdon-Sanderson objected to his use of the word “response” and recommended rejection of a Mimosa paper. The Royal Society published none of Bose’s plant research for more than a decade. It elected him a Fellow in 1920.
Later research supported his central claim. Shepherd notes that researchers studying Mimosa today identify the phloem as the main route for its action potentials. In 2018 a team led by Masatsugu Toyota and Simon Gilroy reported in Science that a wounded leaf sends a wave of calcium, triggered by glutamate, to distant leaves at about one millimetre a second. The wave switches on defences in leaves the insect has yet to reach.
Plant defences and the world’s crop losses
Plants face constant attack. Some 40 per cent of global crop production is lost to pests each year, according to an FAO-commissioned review reported by UN News and Down To Earth in 2021. Plant diseases alone cost the world economy more than $220 billion a year, UN News reported. The impulses Bose recorded are part of the means by which a crop warns its own distant leaves of attack. Any serious effort to cut those losses has to include the plant’s internal defences.
Bose showed that a plant registers harm and that the record can be measured. His work asks farmers and scientists today to read those records and treat the plant’s own defences as part of crop protection.
