A growing world population means that more food is needed which in turn may require more land to grow food crops. More agriculture, however, results in increased irrigation, particularly for food crops such as maize and wheat – especially in dry regions. Combined with the use of fertilizer, this leads to salt accumulation in soils. To be able to use saline soils, naturally salt-tolerant plants, the so-called halophytes, are of great interest. The pseudo-cereal quinoa (Chenopodium quinoa) is one of them. Quinoa originated in the Andean region and is adapted to harsh environmental conditions. In the South American mountain range, the cereal-like plant has been used as a food crop for 7000 years. Gluten-free and high in vitamins, the edible seeds have now found their way into European supermarkets.
A growing world population means that more food is needed which in turn may require more land to grow food crops. More agriculture, however, results in increased irrigation, particularly for food crops such as maize and wheat – especially in dry regions. Combined with the use of fertilizer, this leads to salt accumulation in soils. To be able to use saline soils, naturally salt-tolerant plants, the so-called halophytes, are of great interest. The pseudo-cereal quinoa (Chenopodium quinoa) is one of them. Quinoa originated in the Andean region and is adapted to harsh environmental conditions. In the South American mountain range, the cereal-like plant has been used as a food crop for 7000 years. Gluten-free and high in vitamins, the edible seeds have now found their way into European supermarkets.
Quinoa uses bladder cells for desalination
Quinoa, which is rich in minerals and vitamins, sequesters excessive salt to hair-like bladder cells. This morphological adjustment makes the plant tolerant to saline conditions. These final storage sites for salt connected to the outer cell layer of the leaves prevent toxic levels of sodium chloride (NaCl), also known as table salt, from building up within the leaf tissue. Led by Professor Rainer Hedrich from the University of Würzburg, an international team of researchers comprising scientists from Munich, Genoa (Italy), Hobart (Australia) and Shanghai (China) and Riyadh (Saudi Arabia) has now figured out the molecular mechanism of how bladder cells store salt. They have published their results in the journal Current Biology.
Salt transport from the soil into the salt bladder
When quinoa is exposed to saline soils, sodium and chloride ions travel from the root through the shoot and the leaves into the salt bladders where they are ultimately stored in vacuoles. On their way into the salt bladders, the ions have to overcome several membrane barriers. This is accomplished by transport proteins which are specialised for sodium (Na+) and chloride (Cl-) ions.
Read more at University of Würzburg
Image: Quinoa stores salt in the bladder cells on its leaves. (Credit: Jennifer Böhm)
