Iit Mandi Scientists Identify Cellular Signature Of Anaesthetised State In Plants

The scientists at the Indian Institute of Technology (IIT) Mandi, have achieved an important breakthrough, that may advance our understanding of consciousness and how living beings react to anaesthesia, the institute said on Monday.

In two recent seminal articles, published in internationally recognised journals, advanced biology and chemical and biomedical imaging, they discovered that plants cellular world respond to anaesthesia through a remarkably synchronised manner and follow a hierarchical cascade mechanism for precise and sequential shutdown of intracellular components under anaesthetic stress, even though the plants do not possess either a brain or nervous system.

The study was conducted under prof Laxmidhar Behera, director, IIT Mandi, and prof Chayan Kanti Nandi, with a group of scientists. With the help of state-of-the-art live cell microscopy techniques, the scientists were able to examine the impact of anaesthesia on the cells of tomato (Solanum lycopersicum) and brinjal (Solanum melongena) plants — two of the most widely grown vegetables in India.

The researchers in their first paper showed a precise and sequential shutdown of different cellular components under anaesthetic stress; they called this as “hierarchical cascade of organellar silencing”. The findings represent the first comprehensive model of sequential causal structure and hierarchical cascade of organelle collapse such as mitochondria (the cell’s power generators), lysosomes (the waste disposal units), vesicle trafficking (material transport units), Chloroplasts (the photosynthesis units) and nuclear architectures (the Cell’s command centre) under anaesthesia in plants. The team observed that shut down occurs in a specific, predictable order with the nucleus at last. When the anaesthetic was removed, recovery happened in the reverse sequence. Crucially, the nucleus was identified as the master controller of this recovery: the organelle that coordinates the return of the entire cell to normal functioning. This is the behaviour not of a passive system reacting to a chemical, but of a system that responds in an organised, purposive way.

The most astonishing discovery was made in a consecutive second experiment. The researchers describe it as a “strikingly non-local” phenomenon — and it is the finding that has drawn the most attention.

Inside each plant cell sits a nucleus, within which the cell’s DNA is packaged in two forms: euchromatin (genetically active, loosely packed DNA) and heterochromatin (inactive, tightly packed DNA). The research found that under normal conditions, the nuclei are randomly oriented and moved across plant cells. Under anaesthesia, they are highly organized and respond in a co-ordinated manner. Further, the euchromatin inside each nucleus moved simultaneously to the outer periphery of the nucleus. The heterochromatin stayed put.