Researchers have found a way to prevent flowers from freezing that they say could increase production in agriculture and floral cultivation.
The procedure, so far tried in just a single species, Arabidopsis, uses a protein found naturally in all plants.
If it can be extended to other species, it could be especially useful for citrus producers who can lose millions of dollars in long frosts, the University of Hong Kong researchers say.
The team found that the ACBP6 protein, when present in large amounts in flowers of a small plant related to the Chinese vegetables choi sum and kai lan, protected them from freezing at temperatures below zero Celsius.
They genetically modified the plant, Arabidopsis, by adding extra DNA to promote production of the protein and achieved the freeze-tolerance result.
"We wanted to test whether the protein affects the flowers in facing cold stress," Professor Chye Mee-len, who led the team, said. In the experiment, they put 270 wild Arabidopsis flowers and 540 modified flowers in four degrees Celsius for three days to acclimatise, then minus seven degrees Celsius for an hour, and four degrees Celsius for 12 hours to allow them to recover.
They found that 86 per cent of the modified flowers had intact petals, while only 54 per cent of the wild ones did. The results were published in the international journal Plant and Cell Physiology in February.
The Hong Kong team is now working with Australian researchers to apply the findings to the agricultural industry.
Chye said the hardest part of the three-year study was cutting the hundreds of flowers and counting the number that froze.