“New lotus effect” found, according to Annals of Botany blog 28 November and Plant, Cell & Environmen doi:10.1111/pce.12163. Lotus plants are well known for their water-repellent self-cleaning leaves, a property that has been copied by chemical engineers and called the “lotus effect”. Scientists studying the internal workings of lotus plants have now found they have another clever function – active ventilation.
Plants that grow in water have their roots and rhizomes embedded in anoxic waterlogged soil, but these structures need oxygen, just like any other living tissue. Scientists have found lotus plants have “a complex system of gas canals that channel pressurized air from its leaves, down through its petioles and rhizomes, before venting this air back to the atmosphere through large stomata found in the centre of every lotus leaf”. These large stomata are named central plate stomata and sit over a gas canal junction that connects with two-thirds of the gas canals within the leaf blade and a large gas canal within the leaf base that also connects with gas canals in the rhizome. Philip Matthews and Roger Seymour of University of Adelaide studied the activity of the central plate stomata and found they are open in the morning, closed in the middle of the day and reopen in the afternoon. This system of active stomata and gas canals enables the plant to send oxygenated air down to the rhizome and reverse the flow to bring carbon dioxide from the rhizome up to the leaves, where it can be used for photosynthesis. The researchers concluded: “These results demonstrate a novel function for stomata: the active regulation of convective airflow”.
Editorial Comment: This new research reminds us there is more to being a water plant than just being in water. The standard evolutionary story about water-dwelling flowering plants, like lotuses, is they once were algae, such as pond scum and seaweed, which then moved onto land and evolved into mosses and liverworts, which eventually became flowering plants, via ferns and cone plants. Then some flowering plants then ‘re-evolved’ back into the water and became lotuses, water lilies, etc. Plants that are growing on land, where air permeates the soil, do not possess any type of ‘active ventilation’, but if the evolving lotus plants did not already have such active ventilation, they could not even begin to grow in anoxic waterlogged soil. The perennial evolutionist Catch 22 again. But this is no problem if you believe what Genesis tells us, i.e. plants were intelligently made as separate kinds, with all the created features needed to live in the environment they were placed in. (Ref. botany, gas exchange, aeration)
Evidence News 24/13, 4 December 2013