Scientists in Singapore, Malaysia and Hong Kong identified what gives durian its distinctive aroma that does not exactly please the human collective.
Through advanced sequencing technology, researchers at the National Cancer Centre Singapore (NCCS) and Duke-NUS Medical School mapped the genome of the fruit using a popular variety called Musang King.
They found that the fruit has around 46,000 genes — twice as much as that of humans. This is not totally surprising, however, as plants often have more complex genes than animals.
The more fascinating discovery came as researchers focused on methionine gamma lyase (MGL), an enzyme that regulates the production of volatile sulfur compounds (VSC) which consequently give off the fruit’s infamous odor.
They found four copies of MGL in durian’s genome, while related plants such as cacao and cotton only have one. They also observed that these MGLs are only active when the fruit is ripe.
“The durian smell has been described as a mix of an onion-like sulphury aroma with notes of sweet fruitiness and savoury soup-seasoning. A key component of the durian smell are volatile sulphur compounds, or VSCs, which have been characterized as decaying, onion-like, rotten eggs, sulphury and fried shallots,” said Bin Tean Teh, deputy director at NCCS and co-author of the study.
Interestingly, the researchers learned that durian is actually related to cacao — where chocolate comes from — after tracing its evolution 65 million years back.
The study, published in the journal Nature Genetics, was funded $500,000 Singapore dollars ($368,622) by anonymous donors who claimed to be “fellow durian lovers.”
Understanding the genome of durian, hailed in Southeast Asia as the “King of Fruits,” is important for its conservation. There are at least 30 other durian species, 11 of which are edible, according to The Straits Times.
Duke-NUS’s Patrick Tan, study co-author, hopes for further research (via Nature):
“Unfortunately, several of these species are endangered. We hope to work with experts in the region to characterize the genomes of these other species, to protect their biodiversity and gain further insight into these fascinating plants.”