New research gives insight into how “Living Stones” adapt to extreme conditions

Research by scientists at the University of Sheffield has given new insight on how some plants adapt to extreme conditions which could help in the future development of efficient crops. The study was carried out on plants native to southern Africa known as "Living Stones", or Lithops. These little succulents survive in the blazing deserts and rocky ground of southern Africa by blending in with surrounding pebbles to avoid being eaten and by burying themselves underground. Now researchers have discovered how the partially subterranean "Living Stones" still manage to harvest enough sunlight while avoiding drying out in the parched landscape, according to a study published in the journal PLOS ONE. The Sheffield-based team used a combination of cutting-edge techniques to show that individual leaves of Lithops species are adapted for both high-light and shade-tolerance, revealing for the first time the novel combination of physiological mechanisms used to optimize simultaneous above-ground and underground photosynthesis while minimising water loss. The research shows Lithops combines a top surface with "windows" of translucent tissue that allows light through to photosynthetic tissues deep in the underground portion of the leaf, with a biochemical sunscreen to block out harmful UV light. To offset damage to the plant associated with too much sunlight, the plants also use a protective mechanism known as non-photochemical quenching in the above-ground parts of the leaves.