Cosmos
From the Cosmos newsroom.
Plants have evolved to optimise the timing of growth and flowering with seasonal light and temperature patterns, but climate change is beginning to affect their ability to respond.
Despite an overall warming climate, late spring frosts are occurring more often than they used to. Frosts, especially if they occur during flowering, can drastically reduce wheat yields across the Australian cropping belt.
Dr Fernanda Dreccer, principal research scientist at CSIRO, Australia’s national science agency, says frosts inflict damage on plants at a cellular level, where cell membranes are made of lipids, fatty waxy or oily compounds.
“When plants encounter cold or freezing night-time temperatures, the lipids in their cell membranes compress,” Dreccer says.
Upon warming, the membranes often puncture, leading to dehydration and often irreversible damage.
Modelling carried out by the Grains Research and Development Corporation (GRDC), suggests reducing crop frost sensitivity by as little as 1 degree Celsius would increase growers’ annual return by about $360 million.
CSIRO, with funding and other support from the GRDC and others, is growing wheat cultivars under a range of environmental conditions, including mimicking exposure to frost and investigating genes, metabolites (substances produced during metabolism), and plant structures to determine what makes wheat more or less sensitive to freezing conditions.
One research project is focussed on finding wheats with an enhanced abilities for cell membranes to maintain flexibility and for cells to remain hydrated under low temperatures.
“Membrane flexibility is determined by the plant’s metabolite and lipid profiles, and we’re examining which genes underpin the right chemistry to make wheat less sensitive to frost” Dreccer says.
Read more about wheat research
Another project is examining genetic factors associated with frost sensitivity. Senior principal research scientist Dr Chris Helliwell at CSIRO believes it’s only a matter of time before markers for genes that control frost tolerance will be identified.
“We’re targeting an early stage in reproductive development, which is particularly sensitive to frost,” Helliwell says. There are more than 400 wheat varieties to test.
“Because it’s difficult for plant breeders to select for frost tolerance, current varieties may or may not have those particular markers.
“Once you know what they are, breeders can then select for the lines that have those markers in them as part of their breeding process.”
A version of this article first appeared in CSIRO News.
