FEEDING THE PLANET

By Pam Eastlick

Welcome to The Deep science and technology column where we cover topics from the deep sea to deep space and beyond.

I’ve decided that it’s time to take a look at those other living things that share the planet with us. No, not the animals, we’ve visited them several times recently, and not the microbes even though technically we share the planet with them and not the other way around, but those living things without whom we would die very quickly. Stumped? They make your oxygen for you and without them you’d starve. We’d do just fine without the other animals, thank you, but your very existence depends on the plants.

We’ll start our journey into the photosynthetic part of the kingdom with a couple of stories about a plant that’s very important right here in the Marianas. Rice.

RICE IN TROUBLE

Huge floods in the Philippines, India’s delayed monsoon, and extensive drought in Australia all took their toll on last year’s rice crops, demonstrating the vulnerability of rice to extreme weather.

The magazine Rice Today (I bet you didn’t know there’s a whole magazine devoted to rice, did you?) recently focused on climate change and its potential impact on rice. They report that the International Rice Research Institute (IRRI) has mapped rice-growing regions in the Philippines that are most likely to experience the negative effects of climate change, showing the extent to which climate change threatens rice production.

Luckily for the rice eaters of the world, the IRRI has solutions to help farmers cope with climate change. Cyclone Nargis wreaked havoc on the country of Myanmar and its rice crops in 2008. Since then, IRRI has sent submergence-tolerant and salt-tolerant rice varieties for testing there as more resilient options for farmers.

Massive rat infestations in Myanmar followed cyclone Nargis and the rats have also been causing trouble in Laos and Bangladesh, where the rodents ate up to 100% of rice crops, invaded house stores of food and bit sleeping people.

The IRRI sponsored a Rice Genetics Symposium in the Philippines last year where scientists exchanged information about the latest rice genetics research. In California, rice growers are directly funding their own research to develop rice varieties suited to their conditions. The California growers are trying to meet the global shortfall aggravated by drought in Australia. In sub-Saharan Africa, rice growers are being guided by research to help them adopt suitable mechanization techniques to improve their production.

Rice is the second most cultivated starch after corn and it provides the bulk of the calorie intake for most of Asia. China and India are the world’s largest rice producers but most of their production is consumed ‘in-house’.

Unfortunately for the future, much rice is produced in river deltas that are prone to flooding and salt contamination if world sea levels rise.

BUT HELP IS ON THE WAY

Although more corn is produced than rice, rice actually feeds over half of the world’s population. Rice hasn’t changed as much in appearance from its wild counterparts as corn has, but it is domesticated rice that provides almost all the world’s rice crops. But domesticated rice is genetically static and it’s hard for the plant to adapt to changing growing conditions. There are traditional varieties of rice that are still genetically evolving. Researchers hope to tap into these traits to improve crops worldwide.

Scientists from Washington University in St. Louis and Chiang Mai University in Thailand are showing how natural genetic drift and the agricultural practices of traditional farmers combine to influence the genetic diversity of a given strain of rice.

The researchers studied a variety of rice grown by the Karen people in Thailand and compared the genetic variation among the same variety of rice grown in different fields and villages. They discovered that the varying genetic types of the rice population occurred (unsurprisingly) in much the same pattern as the genetic diversity of native plant species. The further apart the rice fields are, the more genetically distinct they are.

In the vast delta of the Chiang Mai river, farmers grow modern high-yield rice. In the hills, the Karen people practice traditional agriculture, growing ancestral varieties of rice with traditional practices. Expert farmers play a role in maintaining their crop’s genetic diversity by exchanging and choosing seeds to plant the following year.

The researchers discovered that one farmer had had a genetic mutation in one of his fields. One of the rice plants produced a purple head. He was very curious and removed the seeds to grow in an isolated area because he wanted to see what it looked like and tasted like. The researchers said this was probably how humans domesticated plants, smart people were making smart choices in what to plant and grow.

Most of today’s crops have been genetically optimized to consistently give large yields. Seeds are purchased from a supplier and the plants are all genetically similar. They may be extraordinarily important in feeding the world, but their genetic sameness leaves them vulnerable to change.

The rice grown by the Karen people is genetically dynamic, because of genetic drift and the farmer’s artificial selection. Each year, the farmers choose the seeds that grow best in their fields, which may differ in soil type, elevation, and temperature from other fields. Their crops are constantly evolving in response to local conditions.

Although most agriculture in the United States for instance, focuses on growing high-yield crops to produce food for people living in cities, varieties of corn and other crops exist in seed banks.

The Hopi Indians in Arizona are also beginning to concentrate on growing their native varieties of corn. These varieties are important because they’re adapted to hot and dry conditions, something that will become more prevalent as the climate warms.

So here’s to the Karens and the Hopis. Their traditional ways may keep all of us from starving later on!

Traditional varieties of rice provide a genetically evolving pool of traits that can be tapped to improve crops worldwide, a new study suggests. (Credit: National Science Foundation)

So . . . . if we lose rice and we lose corn, what are we going to eat? Hang in there! Help is just around the corner, in a very unexpected form.

JUST EAT THE WEEDS

Anyone who has ever made a trip to the southeastern United States definitely noticed all those vines that hang all over everything. That’s kudzu, a vining member of the pea family that has been called “The vine that ate the South”

Kudzu has overgrown almost 10 million acres in the southeastern United States, but researchers in Alabama and Iowa are reporting the first evidence that root extracts from kudzu show promise as a dietary supplement for a high-risk condition, metabolic syndrome, the ‘fat disease’ that affects almost 50 million people in the United States alone.

People with metabolic syndrome are obese, have high blood pressure and high cholesterol, and problems with their body’s ability to use insulin. Those disorders mean a high risk for heart attacks, strokes, and other diseases. Researchers have been seeking natural substances to treat metabolic syndrome. The current study evaluated kudzu root extracts, which contain healthful substances called isoflavones.

An excessive amount of glucose in the blood is linked to both diabetes and obesity. An extract from kudzu roots called puerarin (the plant’s scientific name is Pueraria lobata) seems to regulate glucose by steering it to places where it’s needed, like muscles, and away from fat cells and blood vessels.

The study found that a kudzu root extract had beneficial effects on lab rats used in a study on the causes and control of metabolic syndrome. After two months of taking the extract, the rats had lower cholesterol, blood pressure, blood sugar, and insulin levels that a control group not given the extract. Although more work remains to be done (as always!) kudzu root just could be a magic bullet for metabolic syndrome and go from “The plant that ate to the South” to “The plant that made us healthy”!

Kudzu, a nuisance vine, shows promise as a dietary supplement that fights an unhealthy condition called metabolic syndrome. (Credit: Wikimedia Commons)

One wonders what miracles lie in the roots of tangan-tangan or Kadena de Amor? Of course, I’ve been saying for years that there’s a very simple way to deal with our brown tree snake problem. Just convince the Chinese and other Asians that some part of the snake (extraction of which involves killing it) is a powerful human aphrodisiac. Voila! No more snake problem!