A team of scientists from Brock University and the University of British Columbia, Canada, has sequenced the genome of the English lavender (Lavandula angustifolia), an economically important plant widely grown around the world.
The English lavender (Lavandula angustifolia). Image credit: Rebekka D.
The lavenders comprise the genus Lavandula, with over 32 morphologically distinct species.
Among these, a few species including the English lavender, the spike lavender (Lavandula latifolia), and their hybrid, the Lavandin (Lavandula x intermedia), are widely grown around the globe for their essential oils, which are frequently used in perfumes, pharmaceutical preparations, cosmetic products, and antiseptics, among others.
With an estimated production rate of over 1,500 metric tons/annum, these oils significantly contribute to the multibillion-dollar flavor and fragrance industry worldwide.
To better understand the genetic makeup and key pathways that control essential oil production, secretion, and storage, a research team led by Dr. Soheil Mahmoud of the University of British Columbia and Brock University’s Dr. Ping Liang generated the first draft genome assembly for the English lavender.
“We have studied lavender for a long time,” Dr. Mahmoud said.
“We have always been curious about this plant: why is it drought tolerant? why is it pest tolerant? what makes it smell so sweet?”
The researchers found that the lavender has a moderately repeated (over 48% repeated elements) genome of 870 million base pairs.
It contains 62,141 protein-coding genes and 2,003 RNA-coding genes, with a large proportion of genes showing duplications.
“Researchers now have access to the lavender genome sequence and from here, they can discover more about the plant,” Dr. Liang said.
“Given the economic status of lavender and its applications of essential oils in many industries, the lavender draft genome sequence serves as a significant genetic resource for continued lavender research.”
“The best way to describe our findings is that we have built the roadmap for the discovery of the genetic elements that define lavender,” Dr. Mahmoud added.
“Now researchers can follow our map and go into the wilderness and explore even further. It’s opening the door for more analysis of the plant for its future potential.”
“For example, the draft genome helps scientists quickly discover genes that direct essential oil production, to understand regulatory elements that control the expression of these genes, and to learn how the genome works as a whole.”
Many high-yield lavender species produce some undesired elements such as camphor.
“The quality of lavender’s essential oils greatly depends on the characteristic scent of the oil, which is determined by certain phytochemicals called monoterpenes,” Dr. Mahmoud explained.
“Camphor contributes an off-odor, and its presence in the oil lowers quality and market value. On the other hand, high levels of linalool and linalyl acetate are desired in lavender oils.”
Additionally, the genome sequence can help researchers develop genetic markers for ‘fingerprinting’ and identification of various lavender species and varieties.
The team’s results were published in the journal Planta.
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Radesh P.N. Malli et al. De novo sequencing of the Lavandula angustifolia genome reveals highly duplicated and optimized features for essential oil production. Planta, published online September 29, 2018; doi: 10.1007/s00425-018-3012-9
