Scientists track messenger signals within plants
For the first time, scientists have revealed plants passing messenger signals for eating, breathing. The messages were passed using sugar, and a chemical involved in energy production called meleic acid.
Scientists have known about a sophisticated internal communication system for optimising energy production, as well as chemical signals relayed between plants to warn of predators or of rainshowers. Now, an international team of researchers have identified molecular messengers that control the breathing and feeding of plants. The discovery could have implications in agriculture. The discovery advances the scientific understanding of how plants coordinate and control their metabolisms, the chemical reactions necessary for energy production, with the external environment. The strategy allows for the plants to optimise growth and survival strategies. A paper describing the research has been published in Nature Plants.
The outermost layers of leaves contain a type of cell known as guard cells, that surround and control the width of microscopic pores in the outer layer of the leaf, that influences crucial processes such as energy production and water loss. Essentially, the stomata are the mouths of the plants from which they suck up carbon dioxide to make carbohydrates for energy, and release water vapour back into the atmosphere. While it was known that the stomata respond to light, researchers have found hints of internal signals that control the guard cells. For decades, scientists have been trying to better understand how the internal cells of the leaf communicate with these guard cells.
A long series of careful experiments
The researchers were able to identify the chemical messengers used to control the guard cells by careful research on mouse-ear cress and fava beans. The apoplastic flued found between plant cells were exposed to either red light or darkness. The red light stimulates photosynthesis. The researchers were able to isolate and characterise the metabolites inside the fluid, discovering 448 chemical compounds, many more than were previously known. The researchers were able to identify sugar and maleic acid as the components that increased when exposed to red light, activating photosynthesis. The researchers were able to confirm that sugars signaled the stomata to open more widely. The new research improves the scientific understanding of the internal communication systems of plants.

