Unravelling how genes control colour in petunias has won Nick Albert the 2020 Hamilton Award and could help breed more nutritious fruit.

Understanding how flowers turn colour on and off has won plant geneticist Dr Nick Albert the Hamilton Award, the Royal Society Te Apārangi Early Career Research Excellence Award for Science.

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Nick started his research in a glasshouse with specially bred 'mutant petunias.' He says that the petunias are "really interesting tools to understand how genes work together to turn on the pathway that actually makes the pigments."

Nick says that the colour red evolved quite early on in land plants and it is often associated with stress.

"It behaves as a sort of sunscreen against too much intense light."

Red is also an important signal for animals - including humans - to "say 'eat me - I'm ready' or 'come and pollinate me'."

Red, blue and purple are produced by abundant anthocyanin pigments.

The genetics of colour

Nick says he is fascinated by how one cell gets a message that tells it to be coloured, while the cell next door doesn't get the message.

"It's all genetically controlled and that's really interesting to me," says Nick. "How do you get these ordered patterns out of, essentially, chaos."

He says there are about 20 genes that need to be turned on at the right time to produce colour. "If you don't get them all turned on then you don't get colour."

"But there are other genes, the ones that I'm working on, and they act like a switch and turn that whole pathway on at the right time."

Nick says there might be a further 10 genes involved in the switching task.

Improving fruit

As Nick and his colleagues unpick the genetic secrets of colour in plants, they are beginning to use that information to improve colour in fruits such as apple.

Colour in fruit has health promoting benefits as well as being visually appealing, yet apples, for example, struggle to produce colour in warmer temperatures.

Nick says using genetics can help in breeding programmes to enhance fruit colour under a changing climate.

He also says that understanding colour genes in wild bilberry fruits, which have coloured flesh as well as coloured skin could help in the breeding of blueberries with the same trait…

Go to this episode on rnz.co.nz for more details