Cold tolerance mechanism identified
Researchers from the US Michigan State University (MSU) have identified a key gene, dubbed SFR2, that protects some plant chloroplast and cell membranes from damage by freezing temperatures. SFR2 is a galactopeptide lipid remodelling enzyme found in the outer chloroplast envelope membrane. It changes the lipid structure of cell membranes to accommodate the reduction in cell volumes caused by dehydration consequent to freezing. Under freezing conditions, lipids in the membranes of freeze-tolerant plants are removed and converted to oil that is stored in droplets, retaining membrane integrity, keeping membranes from fusing with one another and conserving the energy by storing oil droplets, the researchers say.