a day ago
Researchers using cryopreservation to save critically endangered Gossia gonoclada
Cryopreservation was once the stuff of science fiction, but now the technology is being used to help save a critically endangered tree in south-east Queensland.
There are only about 380 Gossia gonoclada, or angle-stemmed myrtle, left in the wild, mostly found in riparian and vine forest areas around Logan and parts of the Gold Coast.
The small tree has dense, glossy, bright-green leaves, and plays a role in local ecosystems — but it's under severe threat.
A fungal disease known as myrtle rust — which damages new growth — along with land clearing and rising temperatures, has drastically reduced the tree's numbers.
Jingyin Bao, a PhD student at the University of Queensland, has spent three years developing a scientific protocol to indefinitely store plant tissue at ultra-low temperatures.
"The idea is to safeguard these species by storing the healthy regenerable plant tissues so that one day they can be used to grow new plants in case the species becomes extinct in the wild," Ms Bao said.
Her work involves taking tiny shoot tips — or the growing points of the plant where new leaves emerge — treating them with a cryoprotective solution, and freezing them in liquid nitrogen at temperatures as low as -196 degrees Celsius.
"It's a technology that's been developed for quite a long time, initially for other things like IVF, but the challenge in part for cryopreservation is that you have to develop a protocol for different things every time differently," Ms Bao said.
"So you have to fine tune everything in the protocol in order to make it work for different species.
"For Gossia gonoclada, we don't have any similar protocols that have been developed before, so we have to do it step-by-step."
Dr Alice Hayward, a plant molecular physiologist at the University of Queensland and Ms Bao's supervisor, said it wasn't possible to simply store the tree's seeds because of its fleshy fruit — meaning cryopreservation of shoot tips and tissue was the only viable way to conserve it.
The method also helps preserve and regenerate myrtle rust-resistant individuals, enhancing the species' resilience.
"A lot of our threatened plants, especially tropical species, about 30 per cent don't survive seed storage, so that's where cryo-preservation is really important — just safeguarding and banking the genetic diversity," Dr Hayward said.
Dr Hayward said Ms Bao has already achieved remarkable results. She's been able to grow new trees from regenerated tissue,
"Jinying's been successful in achieving 100 per cent regeneration rate for cryopreservation of Gossia fragrantissima, which is a related species to Gossia gonoclada," she said.
"That's quite unheard of. Often the rates might be between 40 to 70 per cent regeneration."
The project is a collaboration with Logan City Council, which secured about $500,000 in Australian government grants to fund the work.
Lee-Anne Veage, an environment officer with the council, has been working to save the species — named after former Queensland premier Wayne Goss — for more than a decade.
She's affectionately known among colleagues as the "Gossia guardian".
"We estimate we've got about 300 trees in Logan and 80 or so elsewhere — including naturally occurring populations as well as planted ones," she said.
"We've got a recovery plan that's a 10-year plan… [and] that's including monitoring the health, the status against threats like myrtle rust, doing habitat mapping, germplasm collection and writing up a report."
For Dr Hayward, the breakthrough represents an exciting leap forward in her research field.
For everyone else, she said, it could be summed up with a pop culture reference.
