Squeezing more oil from the vitally important palm

Carl Zimmer / New York Times News Service /


Published Aug 1, 2013 at 05:00AM / Updated Nov 19, 2013 at 12:31AM

You may have never set eyes on an oil palm tree, but it’s probably an intimate part of your everyday life. Whether you start your day with a shave or an application of lipstick, you are probably putting the oil from the tree’s fruits on your face. You buy a doughnut on the way to work, and with each bite, you swallow some of the palm oil in which it was cooked. After work, you stop at the supermarket, and about half the products on the shelves contain palm oil. Before bed, you scrub your face with soap and brush your teeth with toothpaste. They’re both palm oil’s way of wishing you good night.

In just the past few decades, the oil palm tree Elaeis guineensis has become a huge global industry. In 1961, the world’s palm oil plantations produced 1.7 million tons of oil; today that figure is up to 64 million tons a year. A single acre of oil palm trees can generate up to $4,500 annually. Those prices will probably stay high in decades to come, as demand for the oil increases. China and India are now shifting to using palm oil for cooking food, for example, and some countries are exploring palm oil as a biofuel.

But the oil palm tree industry is also an environmental disaster, according to many conservation biologists. The tree “grows best in those parts of the world that support tropical rainforests,” said Ben Phalan of the University of Cambridge. “Oil palm expansion in recent decades has been one of the main drivers of deforestation in Southeast Asia.”

That expansion has helped push many species, including pygmy elephants and orangutans, closer to extinction. The palm oil industry is also leaving its mark on the atmosphere. Some farmers use fire to clear land for plantations, and swampy forests converted to stands of oil palm trees become more prone to burning. The forests, which store huge amounts of carbon, release it into the atmosphere after they are replaced by plantations.

Last week a team of Malaysian and American scientists published a pair of papers in Nature on the genome of this profoundly important tree. In its 34,802 genes, they have been able to reconstruct millions of years of its evolution. They hope to use that knowledge to grow better trees that can yield more oil — and possibly reduce the pressure on the world’s remaining rain forests.

Conservation biologists hail the research but caution about its potential to help the environmental crisis. The solution to the palm oil problem, they say, lies beyond its DNA.

The ancestors of oil palms split off from date palms about 70 million years ago. They grew across Africa and South America, which were still joined at the time. Over millions of years, the two continents split apart, taking their oil palms with them. And along the way, oil palms got oily.

Most flowering plants grow oil in their seeds as a way to supply their offspring with an energy supply. But some also grow oil in their fruit to attract animals, which eat the fruit and spread the seeds in their droppings. The genome team uncovered some of the molecular changes behind this evolution. Oil palm trees switch on some seed-oil genes in their fruits, for example.

The researchers discovered that a single gene, called SHELL, has a powerful effect on how much oil is produced by different varieties of the tree. Mutations to SHELL can raise the yield of the palm by as much as 30 percent.

Tree breeders will now be able to test seeds to see if they carry the high-yield version of SHELL, for example, rather than waiting for six years for the seed to grow into a tree that bears fruit.

The researchers also hope that their public release of the genome will allow other scientists to pinpoint more genes that might be useful for improving oil palm trees, such as resisting drought and diseases. “We’re not going to stop here,” said Ravigadevi Sambanthamurthi, a biochemist at the Malaysian Palm Oil Board and a co-author of the papers. The board, which is financed by the Malaysian government, paid for most of the research.

Genome-driven improvements to oil palm trees, the researchers argue, could allow farmers to produce more oil on less land. Writing in Nature, they claim that the genome will “help to achieve sustainability for biofuels and edible oils, reducing the rainforest footprint of this tropical plantation crop.” (As a food, palm oil is high in saturated fats, considered unhealthy by the American Heart Association.)

The new study is “a major breakthrough,” said David Edwards, a conservation biologist at James Cook University in Australia. “The only way that we will be able to feed the projected human population of 9 to 10 billion without huge waves of deforestation is through increases in crop yield.”

But Edwards and other conservation biologists doubt that genome-driven improvements can protect forests on their own. If plantations become more profitable, agricultural companies and small farmers will have an incentive to plant more trees. “This increases pressure on converting land for plantations,” said Lisa Curran of Stanford University.

“What is also needed is the political will to ensure that forests are in fact protected,” Phalan said.

Palm oil — used in everything from cooking to lipstick — is undoubtedly important. And the trees — which grow best in the same areas as tropical rainforests — have been called an environmental disaster. Researchers hope they have an answer in new knowledge that may allow them to grow trees that produce more oil.