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Posts Tagged: sorghum

Microbes associated with plant roots could be a key to helping plants survive drought

As sorghum plants cope with drought conditions, the plants' roots and adjoining microbial communities are communicating in a chemical language that appears to improve the plants' chances under water stress.

“It's amazing,” said Peggy Lemaux, UC Cooperative Extension specialist. “We know there are lots of microbes in the soil and, for the most part, ones in the surrounding soil stayed the same under drought conditions. We only saw changes in those microbes closely associated with the roots.”

The role of drought in restructuring the root microbiome was the first published discovery to come out of a sweeping drought research project underway since 2015 in the fields at UC Kearney Research and Extension Center in Parlier. The five-year study, funded with a $12.3 million grant from the Department of Energy, aims to tease out the genetics of drought tolerance in sorghum and its associated microbes. Using sorghum as a model, scientists hope the research will help them understand and improve drought tolerance in other crops as well. 

Sorghum growing in research plots at the UC Kearney Agricultural Research and Extension Center. (Photo: Peggy Lemaux)

The new research results from the lab of USDA's Devin Coleman-Derr at UC Berkeley, published April 16, 2018, in the Proceedings of the National Academy of Sciences, document the fate of microbes associated with sorghum roots under three distinct irrigation regimens. Because the San Joaquin Valley generally sees no rain during the growing season, it is the ideal place to mimic drought conditions by withholding irrigation water.

All plots received a pre-plant irrigation to initiate growth. In the control plots, sorghum was irrigated normally, with weekly watering through the season. In the plot simulating pre-flowering drought stress, the plants received no additional water until flowering, about halfway through the season. The third treatment was watered normally until it flowered, and then water was cut off for the rest of the season.

Beginning when the plants emerged, the scientists collected samples from each plot on the same day and time each week for 17 weeks. In a mini, in-field laboratory, roots, rhizosphere (zone surrounding the root), leaves and soil samples from 10 plants in each plot were immediately frozen and transported to Berkeley, where they were disseminated to collaborators, who investigated the plant and microbial responses at the molecular level.

“When a sorghum plant is subjected to drought, it starts sloughing off metabolites, nutrients and amino acids from the roots. The compounds appear to communicate to the neighboring microbial community that the plant is under stress,” Lemaux said. “That selects out a certain population of microbes. Certain types of microbes increase, others go away. When you add water back, the microbial community returns to its pre-drought population in just a few days.”

The researchers cultured two specific microbes that were enriched in the rootzone under drought conditions. They coated sorghum seeds with the microbes and planted them under drought conditions in a growth chamber. This treatment encouraged the plant to grow more roots.

“The microbes appear to improve plant growth during drought,” Lemaux said. “Those microbes appear to be helping plants survive drought. We didn't know that was happening before we got these results.”

Lemaux said the research might lead to future field use of the research breakthrough.

“A lot of companies are interested in the microbiome,” she said. “Some are already selling microbes to coat seeds.”

Posted on Wednesday, April 25, 2018 at 8:44 AM
Tags: drought (202), Kearney (8), Peggy Lemaux (9), sorghum (8)
Focus Area Tags: Agriculture

A spotlight on sorghum

A rainbow of sorghum varieties. (Photo: Roy Kaltschmidt)
Sorghum might just be one of the most interesting foods you aren't yet eating. This ancient cereal crop is the fifth most important cereal crop in the world, according to the Whole Grains Council. It's a popular food crop in Africa and parts of Asia, yet in the United States, sorghum has been more commonly used for feeding livestock. But that situation may be poised to change, as more chefs and farmers reconsider this ancient food, which is gluten-free, high-fiber and rich in nutrients.

Drought tolerant crop

To learn more about sorghum, we started with one of the nation's leading experts on the crop – Jeff Dahlberg, director of University of California's Kearney Agricultural Research Center in Parlier, CA. Jeff previously served as the USDA Agricultural Research Service (ARS) curator for sorghum. He was research director for the National Sorghum Producers and the United Sorghum Checkoff Program. In 2011, Jeff was recipient of National Sorghum Producers' Outstanding Achievement Award. In other words, he knows his sorghum.

Jeff Dahlberg
The UC researcher tells us this ancient cereal crop can be grown on roughly 85 percent of the arable land available to agriculture.

“The versatility of sorghum allows it to be used in a wide range of food, feed and bioenergy products,” Dahlberg said. “The plant has inherent drought tolerance and can thrive in growing conditions that would seem too harsh for other crops. With more research and outreach, sorghum could be an extremely valuable crop for helping to feed the world in the future as we deal with limited inputs and water.”

Dahlberg first became interested in sorghum as a Peace Corps volunteer in Niger, a land-locked African country that consistently is one of the lowest-ranked in the United Nations' Human Development Index (HDI).

“Niger's farmers relied on rainfall to produce their major staples and sorghum was a crop that did well under limited rainfall,” Dahlberg said. “The crop was extremely versatile in that the grain was used for human food production, the leaves were harvested for animal feed and the stalks, many of which could be as tall as 12 feet, were used as building material. The versatility and the toughness of the crop got me interested in researching what made this crop work.”

For an interesting look at why farmers are considering sorghum, Dan Charles reports for NPR.

Delicious, nutritious food

What has Dahlberg most excited about sorghum is it's potential as a drought-tolerant human food crop.

“Sorghum has real potential as a healthy, low-cost cereal crop for the gluten-free market, but also as an Old World cereal that can be blended with other flours and used in unique breads," he said. “Sorghum doesn't have gluten, so you can't use it for nice leavened breads, but you can use sorghum to make nice biscuits, flat breads, quick breads, cakes, cookies, brownies and pancakes.

Sorghum should be thought of as whole grain flour that has a neutral color, little taste and unique cooking characteristics. Dahlberg admits his favorite way to eat this grain is as a brownie made with sorghum flour, but he says the plant “can be extruded to produce excellent snack and cereal products. It can be popped like popcorn, flaked and otherwise processed like other cereals.”

Sorghum syrup is a well-known sorghum product. (Photo: Tony Monica)
Recipes and nutrition

To find delicious ways to enjoy sorghum, we went in search of some good recipes.

These five ways to eat sorghum from thekitchn got us thinking. Why not use sorghum instead of rice for a change in salads? Also, the Mexican sorghum bowl looks delicious.

More fun serving ideas can be found at American Sorghum's page. Did you know there are now sorghum beers?

We also have our eye on this sorghum salad from Whole Grains Council; it includes oregano, feta cheese and pine nuts.

Sorghum syrup is an old-fashioned Southern favorite. As Sherry Leverich Tucker explains in this interesting Mother Earth News article, this sweet, dark, heavy syrup is made by cooking the juice squeezed from the sorghum cane. Just don't call it molasses, which is derived only from the process of making cane sugar. But do use sorghum as you would molasses in recipes. For ideas, consider these recipes from Southern Living. Beef ribs with sorghum glaze, anyone?

It's healthy: Medical Daily reports, “Sorghum has high nutritional value, with high levels of unsaturated fats, protein, fiber and minerals like phosphorus, potassium, calcium and iron. It also has more antioxidants than blueberries and pomegranates.”

In an old episode of the television show Cheers, the protagonist Sam Malone says, “I didn't say I wanted sorghum, I said I wanted some more gum.”

We think if Sam Malone had actually tried sorghum, he would have preferred it over gum.

Today's post is contributed by Teresa O'Connor, assistant editor of the UC Food Observer. The UC Food Observer is edited by ANR's Rose Hayden-Smith. For policy wonks to the public at large, the UC Food Observer is your daily selection of must-read news from the world of food and agriculture, developed by the University of California as part of the UC Global Food Initiative. The UC Food Observer blog and related social media channels aim to highlight important news and add value to the varied discussions occurring about how to sustainably and nutritiously feed the world. Follow us on Twitter and Facebook.

Posted on Wednesday, March 16, 2016 at 11:34 AM
Tags: Jeff Dahlberg (20), sorghum (8)

Invasive superweed Johnsongrass is the target of a new nationwide research effort

A team of researchers has received a $5 million grant from the U.S. Department of Agriculture to find new ways to combat Johnsongrass, one of the most widespread and troublesome agricultural weeds in the world.

“Johnsongrass is a huge problem,” said Jeff Dahlberg, UC Cooperative Extension sorghum specialist and director of the UC Kearney Agricultural Research and Extension Center in Parlier, Calif. “It impacts many different crops and is very hard to control.”

Dahlberg is part of the team that includes scientists from Virginia, Kansas, North Carolina, Texas and Georgia. Andrew Paterson, director of the Plant Genome Mapping Laboratory at the University of Georgia, Athens, is the lead investigator.

Johnsongrass, one of the most troublesome weeds in the world, is closely related to sorghum, which is grown for food, fodder and biofuel.
Native to the Mediterranean region, Johnsongrass has spread across every continent except Antarctica. It was introduced to the U.S. in the 1800s as a forage crop, but it quickly spread into surrounding farmland and natural environments, where it continues to cause millions of dollars in lost agricultural revenue each year, according to the USDA.

The naturalization of Johnsongrass across much of the U.S. has also allowed the plant to develop attributes — such as cold and drought tolerance, resistance to pathogens and the ability to flourish in low-fertility soils — that make it particularly difficult to control. Adding to the challenge is the adoption of herbicide-resistant crops around the world.

“Herbicide-resistant crops have been associated with a dramatic increase in herbicide-resistant weeds,” Patterson said. “With 21 genetically similar but different types of Johnsongrass known to be resistant to herbicides, it will only become more problematic in the future.”

Over the course of their five-year project, the researchers will work to better understand the weed's capabilities and the genes that make Johnsongrass so resilient. Johnsongrass [Sorghum halepense] is closely related to sorghum [Sorghum bicolor (L.) Moench], a healthy gluten-free grain, animal feed and biofuel crop. Lessons learned from the Johnsongrass research may lead to strategies to improve sorghum.

For his part, Dahlberg plans to use the global information system (GIS) to map the locations of Johnsongrass in California to better record its distribution in the state and to help understand how it spread into California by relating it to other populations of johnsongrass in the U.S.

“Ideally, we will use an app to map, identify, manage, and catalog populations that have developed different traits – such as susceptibility to plant disease, ability to host a particular insect, or resistance to herbicides,” he said.

This information may lead to new management strategies that target and curb its growth, providing farmers with more options to combat the invasive plant. The researchers also hope that learning more about the fundamental structures that give Johnsongrass its unusual resilience will pave the way for new genetic tools to improve useful plants, such as sorghum.

Other researchers working on this project are Jacob Barney, Virginia Tech; C. Michael Smith, Kansas State University; Wesley Everman, North Carolina State University; Marnie Rout, University of Texas, Temple; and Clint Magill and Gary Odvody, Texas A&M University.

Posted on Friday, March 4, 2016 at 8:28 AM
Tags: Jeff Dahlberg (20), Johnsongrass (1), sorghum (8)

Sorghum growing in the San Joaquin Valley is the subject of $12.3M study of crop drought tolerance

Sorghum at the UC Kearney Agricultural Research and Extension Center, where field testing will take place next year. (Photo: Peggy Lemaux)

UC Agriculture and Natural Resources researchers are working in the San Joaquin Valley with UC Berkeley and Department of Energy (DOE) scientists to examine the role of epigenetics in plant survival under drought conditions, an increasing concern for agriculture as the effects of climate change are felt in California and globally.

The five-year study is funded with a $12.3 million grant from the DOE.

Epigenetics is the study of trait variations caused by environmental factors that switch genes on and off. At the UC Kearney Agricultural Research and Extension Center in Parlier and the UC West Side Research and Extension Center in Five Points, sorghum nurseries will be grown under drought and well-watered conditions to compare the environmental impacts on the plants' gene expression.

“We hope to tease out the genetics of drought tolerance in sorghum,” said Jeff Dahlberg, a sorghum expert who will manage the trials at Kearney. “Using sorghum as a model, we expect this research to help us understand drought tolerance in other crops as well.”

Dahlberg is the director of the UC Kearney Research and Extension Center. The director of the UC West Side Research and Extension, Bob Hutmacher, will manage the sorghum nursery at that facility. Funds from the DOE grant will allow Dahlberg and Hutmacher to hire two research associates and purchase new research equipment, including a new planter, a plot combine, a forage chopper and specialized tools for measuring data.

Peggy Lemaux, UC ANR Cooperative Extension plant biology specialist based at UC Berkeley, is the overall leader of the project, titled Epigenetic Control of Drought Response in Sorghum or EPICON. Other collaborators are Devin Coleman-Derr, Elizabeth Purdom and John Taylor from UC Berkeley; Chia-Lin Wei from the DOE Joint Genome Institute; and Christer Jansson from the DOE Pacific Northwest National Laboratory.

Scientists hope to learn the secrets to the sorghum plant’s tolerance to drought. Shown here is a bee visiting a sorghum flower. (Photo: Peggy Lemaux)
"Historically, the genetic manipulation of crops, which has been critical to increasing agricultural productivity, has concentrated on altering the plant's genetic sequence, encoded in its DNA," Lemaux said. "However, recent studies have shown that environmental stresses – in our case drought – can lead to epigenetic changes in a plant's genetic information. Because epigenetic changes occur without altering the underlying DNA sequence, they allow plants to respond to a changing environment more quickly."

Over the next three years, a variety of observable plant traits will be followed, such as plant height and grain yield. In addition, leaf and root samples will be taken to investigate responses to drought at the molecular level, including how gene expression changes and which proteins and metabolites are altered.

Researchers will also be tracking changes in the sorghum-associated microbial communities in the soil to determine whether they correlate with changes that directly contribute to the crop's drought tolerance. It is now well known that associations of specific bacteria and fungi with plants and animals have positive effects on host fitness. For example, microbes in both plants and humans are known to help fight disease and, in the soil, can help deliver nutrients and other resources to plants.

EPICON efforts will generate a variety of large datasets, which will be shared via an open, online platform that will include methods and results.

"Availability of this data in an open forum will enable comparative genomic studies by other scientists," said Coleman-Derr, a UC Berkeley adjunct assistant professor in plant and microbial biology. "Being able to analyze the large datasets in an integrated fashion will enable a more thorough understanding of the complex and interconnected processes responsible for sorghum's ability to respond positively to drought."

The researchers expect that the project will allow better predictions of how sorghum and other cereal crops are affected by future climate scenarios, and will lead to approaches to improve growth and production of sorghum and other crops under water-limiting conditions in commercial fields and on marginal lands.

The Energy Department's Genomic Science Program is funding this project through its Office of Biological and Environmental Research.


Jeff Dahlberg, jadahlbergt@ucanr.edu, (559) 646-6060

Bob Hutmacher, rbhutmacher@ucdavis.edu, (559) 884-2411, Ext. 206

Peggy Lemaux, lemauxpg@berkeley.edu, (510) 642-1589

Posted on Monday, September 28, 2015 at 9:39 AM
Tags: Bob Hutmacher (3), drought (202), Jeff Dahlberg (20), Peggy Lemaux (9), sorghum (8)

Gluten-free California sorghum is the focus of UC research

Sorghum grain can be milled into a gluten-free flour. (Photo: Wikimedia Commons)
As a Peace Corps volunteer in Niger, Africa, in the early 1980s, Jeff Dahlberg was intrigued by sorghum, a staple food being cultivated by the country’s vast population of poor subsistence farmers.

“I was impressed with the fact that sorghum was so drought tolerant,” Dahlberg said. “They used no irrigation at all.”

More than 30 years later, Dahlberg, the director of the UC Kearney Agricultural Research and Extension Center in Parlier, is still impressed with sorghum and believes it has potential to be a significant crop in California, where water is a serious concern.

Sorghum isn’t a new crop to the Golden State. It was introduced more than 150 years ago. In the 1960s, a half-million acres were planted to sorghum, mainly for animal feed.

“Now, if there were 20,000 acres in sorghum I would be surprised,” Dahlberg said. Alfalfa hay and corn silage are currently the two most common forages at California dairies, which maintain nearly 2 million cows.

Dahlberg initiated a five-year research project in 2012 with funding from UC Agriculture and Natural Resources aimed at reintroducing sorghum as a low-input crop for bioenergy, food and feed in California.

A unique characteristic of sorghum is its adaptability. In many parts of the world, from Africa to India to China, sorghum grain is used to make porridge, flat bread and alcoholic beverages for people to enjoy. In the United States, sorghum has traditionally been considered an animal feed. But growing interest in eating whole grains and gluten-free foods is generating interest in sorghum for human consumption.

Sorghum grain can be milled like wheat. Sorghum flour, which is naturally gluten-free, makes excellent flat breads, cookies, pancakes and waffles, Dahlberg said. By combining with other ingredients that help it maintain loft in the absence of gluten, sorghum can also be baked into traditional fluffy bread and cake.

Whole sorghum grain may be added to soups, makes a dish similar to couscous, and can be popped like popcorn for snacking. The stems of sweet sorghum can be pressed, like sugarcane, to produce sorghum molasses or syrup.

According to the Whole Grains Council, sorghum doesn’t have the inedible hull that surrounds other grains. Since it is typically eaten with all its layers intact, sorghum retains the majority of its nutrients. In addition, the wax surrounding the sorghum grain contains compounds called policosanols, which may have an impact on cardiac health.

Jeff Dahlberg in a sorghum research plot.
The California sorghum research now underway at Kearney and the UC West Side Research and Extension Center is focused on hybrid forage and grain sorghum varieties. The results will also be applicable to varieties for human food and biofuel.

“We’re trying to understand whether or not the hybrids developed for the U.S. Sorghum Belt – Texas, Oklahoma, western Nebraska and South Dakota – are adapted to California conditions,” Dahlberg said. “So far, they are doing very well.”

The forage research will determine how to manage sorghum to maximize yield and reduce water and nitrogen use. Early results show that farmers can save a significant amount of water growing sorghum for dairy silage when compared with corn.

“We use less than 20 inches of irrigation water on our sorghum plots and getting 22 to 25 wet tons of material off a single crop. A corn crop will need 36 inches of water or more,” Dahlberg said.

The crop’s fertilizer needs are also quite low. In fact, too much fertilizer can cause the sorghum stalks to fall down, or lodge, which hinders harvest.

"When California farmers think about growing sorghum for gluten-free food, biofuel or animal feed, they will be able to access information generated by local research to help them make the decision," Dahlberg said.

Posted on Tuesday, November 19, 2013 at 9:50 AM
Tags: Gluten (2), Jeff Dahlberg (20), sorghum (8)

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