The smell of durian has been described by some as "turpentine and onions, garnished with a gym sock" — and scientists have now unlocked the biology behind its infamous aroma which could eventually lead to a better smelling variety.
Many people in South-East Asia, including Professor Bin Tean Teh, love the tropical delicacy, which is known as the "king of fruit".
"It has a very rich, creamy taste. To us it's like a heavenly smell and it melts in your mouth," said Professor Teh, a cancer researcher at Duke-NUS Medical School in Singapore.
Professor Teh is the lead author of a study, published today in Nature Genetics, which has identified key genes that are responsible for the fruit's pungent smell and strong taste.
Professor Teh and colleagues sequenced the genome of the Musang King, a particularly pungent variety of Durio zibethinus that is grown in Malaysia and is banned on many public transport systems in South-East Asia.
Specially evolved to attract animals
His team found around 46,000 genes in the durian's full DNA sequence — twice as many as the human genome — and discovered its heritage can be traced back 65 million years to the cacao plant, from which chocolate is made.
With the fruit's whole-genome sequence in hand, the researchers focused on a particular gene that regulates the production of sulphur compounds, which give off a rotten gas smell.
"We found that this gene is highly expressed only in the fruit — the pulp — but not in the leaves or the stem or the roots," said Professor Teh.
"This gave us the first clue that this is a key gene that results in the strong, pungent smell of durian."
"Our hypothesis is that the smell actually attracts animals to eat the durian and disperse the seed," said Professor Teh.
Important implications for agriculture and biodiversity
Professor Teh said the findings had important implications for the development of the fruit, which is a lucrative food crop worth millions of dollars in South-East Asia.
"Theoretically you could knock out this MGL gene. Then you would get a much lesser smell," he said.
"With the ripening factor as well, you can shorten the whole fruiting and ripening time."
The research could also be used to produce lower sugar varieties — thanks to another group of genes discovered by the team.
Source: abc.net.au
