Plants Genetic Response Changes Due To Stress

CP  |  By Posted: Updated: 05/18/2012 8:08 am

LUBBOCK, Texas - No one's talking about giving intelligence tests, but researchers say they've shown that plants have smarts — the sort needed to help them survive dry times.

Years from now the findings could lead to crops that are better able to withstand drought conditions. Already, studies on two crops have shown they too have short-term memory for surviving dry times, University of Nebraska-Lincoln researcher Michael Fromm's said.

He contends his team's findings are the first of their kind in life forms above yeasts.

The outcome of Fromm's initial study, with a member of the mustard family, confirmed what many nursery professionals and home gardeners have observed: Stressing plants helps them adapt and aids them in surviving transplanting.

Related on The Huffington Post.
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  • 1. Start With The Soil

    Maintaining a healthy garden starts with healthy soil, Singh says. He skipped the bagged potting soil and began the process of creating nature's original fertilizer - <a href="" target="_hplink">the soil food web</a>. To put it simply: The soil food web is a community of soil-dwelling organisms, from bacteria and <a href="" target="_hplink">fungi</a> to earthworms and beetles. As microbes, fungi and bacteria feed on carbon and minerals like calcium, they eventually die off - leaving organic matter and humus protein in their place. Among other benefits, the presence of organic material will significantly reduce the need for irrigation, Singh says. "<a href="" target="_hplink">The EPA will tell you</a> for every 1 percent of organics in the soil, that one acre will hold 16,000 more gallons of water," Singh says. "Healthy soil should have 5 percent organics. That means an acre can hold 80,000 more gallons of water than it's holding now." To achieve a healthy balance of microbes and organic material, Singh has become a composting pro, making his own compost and microbe-rich compost tea to apply to the soil on his farm. <em><a href="" target="_blank">Flickr:</a> <a href="" target="_blank"> Image courtesy of Liz Henry</a></em>

  • 2. Choose The Right Seeds

    "All my plants are called heirloom plants; "heirloom plants" means that seed has been around for 50 years or more and nobody's messed with it," Singh says. "I will not use [genetically] modified seed." "When you buy [modified] seed, next year no other seed will grow there except [modified] seed," he continues. "With heirloom seeds, I keep my seeds. I can use those next year and the year after that." Another drawback of <a href="" target="_hplink">genetically modified crops</a> is possible contribution to weed problems. A <a href="" target="_hplink">study</a> published in the scientific journal <em><a href="" target="_hplink">Nature</a></em> concluded that genetically engineered crops can pass along super-hearty traits to weedy relatives, meaning you could see more pervasive weed problems after using modified seeds. To fight back against a genetically modified takeover in your garden, opt for heirloom or USDA certified organic seeds. Both are available at most nurseries and garden centers. But if you're having trouble tracking down heirlooms in your area, head to <a href="" target="_hplink">Seed Savers Exchange</a> - a nonprofit dedicated to saving and sharing heirloom seeds - for thousands of affordable choices. <em><a href="" target="_blank">Flickr:</a> <a href="" target="_blank"> Image courtesy of LollyKnit</a></em>

  • 3. Utilize Indigenous Plants

    With the right care, climate conditions and sunlight you can grow just about anything in your garden. But why use plants that hail from the other side of the country when you can plant lush greenery native to your home state? Native plants are already adapted to your area's climate and soil conditions, meaning they won't need to be treated with pesticides and will be much easier to keep alive. And since many native plants are severely underutilized and on the verge of extinction, you'll be helping to maintain your area's natural culture just by growing them in your garden. Singh cultivates several species native to Arizona's Valley of the Sun, including wild arugula and <a href="" target="_hplink">golden purslane</a>, a rarely heard of but ridiculously healthy native green that contains 10 times the omega-3 fatty acids as spinach. Not sure how to find plants native to your region? Check out these searchable databases from <a href="" target="_hplink">Plant Native</a>, <a href="" target="_hplink">eNature</a> and <a href="" target="_hplink">The University of Texas at Austin</a> to find the flora and fauna that suits your region best. Who knows? You may even discover an eye-catching bloom or nutrient-packed veggie you've never even heard about! <em><a href="" target="flickr">Flickr:</a> <a href="" target="flickr"> Image courtesy of zoonabar</a></em>

  • 4. Plant Intentionally

    Most of us choose plants for our garden because they produce one of our favorite vegetables or add a pretty touch of color to the plot. But choosing plants intentionally can actually increase the health of your garden and make it easier to care for. Singh plants legumes, alfalfa sprouts and other nitrogen-fixing plants to nourish the soil on his farm. Such plants store nitrogen as they grow and release it when they die and decompose, providing a treasure trove of nutrients for the soil. For best results, allow <a href="" target="_hplink">nitrogen-fixing plants</a> to grow for at least one season. Then till under the plants into your garden and plant the fruits and veggies of your choice, Singh suggests. For even smarter planting, utilize one of the dozens of pest repellant crops - which will naturally keep insects and other unwanted critters away from your garden. Pest repellant plants, otherwise known as "<a href="" target="_hplink">companion plants</a>," include herbs, garlic and snap peas. <em><a href="" target="flickr">Flickr:</a> <a href="" target="flickr"> Image courtesy of woodleywonderworks</a></em>

  • 5. Monitor Nutritional Value

    We all want our produce to be healthy and full of nutrients. But did you know there's a simple and surefire way to measure the quality of fruits and veggies from your garden? To produce the highest quality crops possible, Singh uses a <a href="" target="_hplink">refractometer</a>, also known as a Brix meter, to monitor nutritional value over time. Available in most garden retailers, these gadgets use the <a href="" target="_hplink">Brix scale</a> to measure the amount of light refracted in a liquid. The higher the Brix level of your crops' juice, the higher the dissolved solids such as vitamins, minerals, amino acids and other healthy good stuff. Plants that are undernourished or sprayed with pesticides tend to have a Brix reading of about three or four, while organic produce or healthy plants not treated with pesticides will be between eight and 10 in the Brix count. Using a refractometer to monitor your home garden not only provides quality assurance but also helps you see what's going on in your soil. If your Brix count is low in certain areas, you can begin implementing some of Singh's other techniques to restore nutrients in the soil, yielding healthier and tastier crops. <em><a href="" target="flickr">Flickr:</a> <a href="" target="flickr"> Image courtesy of jayneandd</a></em>

  • 6. Skip The Sprays: You Won't Need Them Anyway

    "[Insects] can't attack healthy plants," Singh says. "If your plants are healthy, you don't need pesticides." So, how can bugs tell if your plants have a clean bill of health? Be prepared, this is going to be a scientific answer: Insects navigate by detecting infrared radiation through their antennae, a concept first explored in depth by American entomologist <a href="" target="_hplink">Philip S. Callahan</a>. Infrared radiation changes based on energy output and rising gas molecules, meaning a thriving field of plants will not send off the same infrared signal to an insect as weak plants that are not generating as much oxygen or energy. A few aphids or bees hovering around your garden is normal and actually helps your plants grow heartier. Spraying pesticides not only introduces chemicals to your otherwise fresh and healthy food supply but also <a href="" target="_hplink">depletes your crops' nutritional value</a> and makes it more difficult for plants to defend themselves. If you notice an insect problem, concentrate on increasing nutrient supply to the soil rather than spraying pesticides. Your crops and your body will thank you later! <em><a href="" target="flickr">Flickr:</a> <a href="" target="flickr"> jetsandzeppelins</a></em>

  • 7. Get Smart About Storm Water

    Your thirsty plants will naturally receive water when it rains. But why not make the most of that rainwater to reduce your plot's water consumption? Even in the Arizona desert, Singh has seen great success by using EPA <a href="" target="_hplink">storm water design</a> practices to maximize rain water and minimize artificial irrigation. "My farm was a flat piece of land, but if you look'll see it's inverted," Singh says. "The inversion means when it rains all the water comes to the middle of my farm." Singh also uses natural soil amendments to increase the soil's infiltration capacity and reduce runoff. For smaller plots like home gardens, the EPA suggests using <a href="" target="_hplink">rain garden</a> methods, which naturally filter out pollutants and allow the soil to soak up 30 percent more rain than a conventional patch of lawn. To start your own rain garden right in the backyard, check out this <a href="" target="_hplink">DIY homeowner's guide</a> from the <a href="" target="_hplink">University of Wisconsin Extension</a>. <em><a href="" target="flickr">Flickr:</a> <a href="" target="flickr"> Image courtesy of jo-h</a></em>

  • 8. Go With The Flow

    Singh learned loads of tricks over the years that help him keep his crops happy and healthy. But mostly, he attributes the farm's success to his connection with Mother Earth, saying "nature has its own consciousness." "It's not me; it's not you. It's nature," Singh says. "These functions are going to happen regardless of what we do." Although Singh is the first to say that most of his farming practices are based in science and biology, he achieves even greater success by incorporating intangibles: Feeling the "rhythm of the farm" and using back-to-basics growing methods taught to him by his father and uncle. Even after laboring on the farm every day for 10 years, Singh smiles and says, "Look at what nature did all by itself, because I fed the Earth." "Everything should be simplicity," he says. "This is all ours. I don't own this; you don't own this. Nature is for us, right?" <em><a href="" target="flickr">Flickr:</a> <a href="" target="flickr"> Image courtesy of Clownfish</a></em>

  • Early Summer Gardening Tips

    Horticultural Specialist Mitch Baker demonstrates gardening techniques designed to help take your spring garden into the summer months.

"It's important that it's in all plants, but the next part of the story will have to move the research forward," Fromm said. "There's no question this is a critical long-term problem. Drought tolerance is extremely important but it's also extremely difficult."

He declined to name the two crops he and his team studied subsequent to work with Arabidopsis — the mustard plant — citing confidentiality issues with the peer-reviewed journal scheduled to publish those results later this year.

In the mustard plant research, Fromm and his team compared reactions of plants stressed by withholding water to those that got water. The ones that went without water — the trained or stressed plants — bounced back more quickly the next time they got dehydrated. Those that got water — the untrained or non-stressed plants — wilted faster and their leaves lost water at a faster rate than the trained ones.

There were changes at a molecular level when the trained plants were deprived of water again. When water was then made available, the changes reverted back to normal levels. That changed, though, after subsequent periods of drought as the plants "remembered" their molecular response to stress.

"There's a connection between the environmental stress, the drought, and the plant response with not only physiological changes but developmental changes," Fromm said. "That's a decision the plant makes that we think this process can influence."

The mustard plant forgot the previous stress "memory" after five days of watering, but the researchers said other plants' memories could be different.

"It kind of backs up what a lot of people have thought," Texas Tech horticulture professor Thayne Montague said. "Once a plant is exposed to stress, drought ... it can be a beneficial response short term. Now, long term that hasn't really been looked at."

One Lubbock woman, president of the city's 60-member master gardener program, said she thinks a plant's roots are keys to drought survival. The shorter the root, a result of overwatering, the less the plant will tolerate drought.

"Plants don't think," Barbara Robertson said. "It almost has to have something to do with the root system. A stressed plant with deep roots is going to do better."

The Nebraska research team's results could be transferred to row crops, such as corn, cotton or wheat, but that potential is still about 20 years away, Fromm said. Ideally, the goal would be to have the memory last from growing season to growing season.

"That may or may not exist," Fromm said. "Our discovery goes just a few days."

Murray Coulter, a genetic biologist who taught at Texas Tech University for more than three decades, said Fromm's research isn't saying plants have a central nervous system and can think. But if it's just one gene that needs modifying, he said, he thinks the technology could be in crop fields in five years.

That would help producers in the world's largest continguous cotton patch, on the South Plains.

"Having a dry season would not impact them economically," Coulter said. "The less water they use the more profit they make."


Filed by Meredith Gillies  |