Weizmann Institute of Science researchers discovered a brown blotch on a plant leaf is a sign that the plant’s defence system is weak and it has been attacked by fungus or bacterium. But the immune system of the plant tries to keep the disease away from spreading by killing the infected cell of the plant. It also kills the surrounding cells of the diseased cell to keep the plant alive.
Scientists discovered the evolutionary origins of any plant’s immune mechanism. Their research explains how plant defence works and how to improve their defence system as death of plants due to plant disease causes billions of dollars of losses worldwide in agriculture.
Few years ago, researchers of America and Australia found out that when a plant kills an infected plant cell, it uses a protein with a segment called TIR. This protein makes a signal molecule inside the plant.
Researchers also revealed that TIR is also used by bacteria to strengthen their immune system and TIR almost works in similar ways in a plant and in a bacterium.
Bacteria continuously fight against a virus named phages which put their genomes into the bacterial cell. Then the cell makes new phage copies and dies. But researchers noticed that as soon as one cell was infected by phages, TIR produces a signal to alert the second cell. TIR also destroys one molecule in the bacteria’s body that kills the phages before it can multiply itself.
Researchers say the signal molecules generated by TIR is similar in plants too. Researchers are trying to fully understand the TIR-produced signaling molecule in plants.
