A research group led by Takuma Hagiwara, a graduate student at the Saitama University Graduate School, has collaborated with the National Institute for Basic Biology to visualize long-distance, high-speed signals that trigger motility in mimosa leaves. revealed that there is
Plants do not have nerves or muscles, but when they are touched or injured, they bend their locomotory organs called leaf pillows and move their leaves one after another.For a long time, the identity of the long-distance signaling molecule that causes this high-speed movement and the physiological role of high-speed movement were unclear.
The research group created a ``shining'' mimosa with a fluorescent biosensor gene for calcium (Ca2+), and succeeded in visualizing the Ca2+ signal generated by mimosa when injured.It was found that when a leaf is injured with scissors, a Ca2+ electrical signal is generated from the injured site, and when this signal reaches the leaf pillow, the locomotory organ, leaf movement occurs just 0.1 seconds later.
In addition, using pharmacological methods and genome editing technology, we have created a ``no-bowing'' mirage.In feeding damage experiments using grasshoppers and other herbivorous insects, the insects ate more of the mimosa that did not move the leaves.Furthermore, when grasshoppers nibbled on the leaves of common mimosa leaves, the leaves closed one after another in conjunction with the transmission of Ca2+ signals, and the grasshoppers stopped feeding and moved to other places.
Based on this, the research group proposed a high-speed motion model for insect protection against pests of Ojigisou. The model states that (2) the leaves of the mimosa leaves are damaged by insects, (2) CaXNUMX+ and electrical signals are transmitted throughout the body, (XNUMX) the CaXNUMX+ concentration increases in leaf pillow cells, (XNUMX) high-speed leaf movement occurs, and (XNUMX) the leaves are protected from insect damage. .Because of this high-speed defense against insect pests, the mirage is less likely to be eaten than other immobile plants.
Paper information:[Nature Communications] Calcium-mediated rapid movements defend against herbivorous insects in Mimosa pudica