Tiny pores on the leaves of plants, called stomata, have a huge influence on the state of our planet. Through the stomata, plants absorb carbon dioxide, which is incorporated into carbohydrates, and release oxygen. But they also lose water through open pores, which can be life-threatening for plants in dry conditions. Plants therefore have developed complex signalling pathways that optimize the opening width of stomata to match the environmental conditions. In response to changes in the availability of light, carbon dioxide and water, they can open or close these pores. How did the signalling pathways that are responsible for this regulation evolve? This is being investigated at Julius-Maximilians-Universität Würzburg (JMU) in Bavaria, Germany, in the team of the plant scientist Rainer Hedrich. "We are currently collecting and analyzing data from different plant species," says Professor Hedrich. He explains that this research also has relevance for agriculture: "Knowledge about the evolution of these signalling pathways could feed into breeding efforts to develop crops that can grow with less water." After all, the majority of the drinking water supplied to plants via irrigation systems is lost through stomatal pores. In view of climate change, plant varieties that can cope well with drought are highly sought-after.
Two open stomatal pores on the surface of a fern leaf, each surrounded by two kidney-shaped guard cells. Right panel: important moments during the evolution of stomata. Stomata probably evolved in an early land plant, from which all today's species descend, but were likely lost in liverworts. Some genes that control stomatal movement in flowering plants likely arose recently, in seed plants, from within ancient gene families that were present in algae. Signalling genes with specific roles in guard cells likely arose after mosses diverged from a common ancestor. Photo Credit: Stephan Liebig

Source: Agriculture and Food News, ScienceDaily. www.sciencedaily.com