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, 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. Researchers have now figured out the molecular mechanism of how bladder cells store salt. They have published their results in the journal Current Biology.
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.
Compared to crops which are not salt-tolerant, these transport proteins do not have to be reassembled with increasing salt load, rather they are already in place before the stress begins. "This strategy enables quinoa to transfer the suddenly occurring salt immediately to the final storage without any further gene regulation steps," the author says.
The properties of this sodium channel not only assure that sodium ions are continuously transported from the leaf into the bladder cells where they can be stored in high concentration. "What's special about this mechanism is that it prevents backflow of sodium and hence the Na+ leakage into the leaves even when the stored sodium reaches very high levels," the first author of the study, says. The sodium channel thus functions as a safety valve, making it the key component of final salt storage in the salt bladders.
When the salt is in the leaves, the Na+ and Cl- ions need to be transported through the plasma membrane into the cytosol (intracellular fluid) of the salt bladders. Analogously to the sodium ions, the plant assures the directional transport of chloride ions into the cell.
In plants, rising sodium chloride levels in the cytosol are toxic for many metabolic processes. Therefore, quinoa sequesters the salt in membrane-enclosed vacuoles outside its metabolically active parts. This second membrane which sodium and chloride ions need to pass is called the tonoplast. Here, too, salt transport takes place in one direction only.
"This study has provided fundamental insights that will allow us to selectively breed salt-tolerant crops in the future," the senior author says. "We have shed light on the molecular components of salt storage. But we want to further investigate how the salt is transferred from the leaves to the final storage site," author says. The salt has to be transported through a small tunnel-like connection, the stalk-like cells between salt bladders and leaf epidermis.
https://www.uni-wuerzburg.de/aktuelles/pressemitteilungen/single/news/einbahnstrasse-fuer-das-salz/
Plants salt storage and disposal mechanism!
- 1,529 views
- Added
Edited
Latest News
A new brain circuit in mice…
By newseditor
Posted 08 May
Mechanism of choline entry…
By newseditor
Posted 07 May
Link between UTI and breast…
By newseditor
Posted 07 May
Sleep resets brain connections
By newseditor
Posted 07 May
Interplay of various enzyme…
By newseditor
Posted 07 May
Other Top Stories
Diabetes dramatically reduces the kidney's ability clean itself
Read more
Artificial intelligence detects osteoarthritis years before it deve…
Read more
Inflammation from sensory neuron activation via optical implant
Read more
Hormone that might help treat malabsorption identified
Read more
New mouse model of tau propagation
Read more
Protocols
Single-cell adhesive profil…
By newseditor
Posted 07 May
Parasympathetic neurons der…
By newseditor
Posted 07 May
Non-invasive measurements o…
By newseditor
Posted 05 May
A validation strategy to as…
By newseditor
Posted 04 May
Generation of rat forebrain…
By newseditor
Posted 03 May
Publications
Truncating NFKB1 variants c…
By newseditor
Posted 08 May
Synaptotagmin-11 facilitate…
By newseditor
Posted 08 May
Astrocytic Slc4a4 regulates…
By newseditor
Posted 08 May
Diabetic retinopathy is a c…
By newseditor
Posted 08 May
A body-brain circuit that r…
By newseditor
Posted 07 May
Presentations
Hydrogels in Drug Delivery
By newseditor
Posted 12 Apr
Lipids
By newseditor
Posted 31 Dec
Cell biology of carbohydrat…
By newseditor
Posted 29 Nov
RNA interference (RNAi)
By newseditor
Posted 23 Oct
RNA structure and functions
By newseditor
Posted 19 Oct
Posters
A chemical biology/modular…
By newseditor
Posted 22 Aug
Single-molecule covalent ma…
By newseditor
Posted 04 Jul
ASCO-2020-HEALTH SERVICES R…
By newseditor
Posted 23 Mar
ASCO-2020-HEAD AND NECK CANCER
By newseditor
Posted 23 Mar
ASCO-2020-GENITOURINARY CAN…
By newseditor
Posted 23 Mar