Sarah Weiskopf places third at the National Wildlife Society Meeting

October 28, 2013 under CANR News

Sarah Weiskopf and Shannon Kachel present their posterSarah Weiskopf, an honors student in the Department of Entomology and Wildlife Ecology (ENWC), presented her poster earlier this month at the National Wildlife Society Meeting in Milwaukee, WI.

The poster, titled, “What do snow leopards really eat? Using genetics to reduce bias in food habit studies,” placed third place at the conference amongst undergraduate presenters.

Weiskopf is completing her senior thesis in Kyle McCarthy’s Rare and Elusive Species Lab, where she works closely with Shannon Kachel, graduate student in ENWC, on snow leopard ecology.

As for the specifics of her research, Weiskopf explained that knowing what snow leopards—an endangered species that live high in the mountain areas of central Asia–eat is critical to their survival. “One of the reasons they’re endangered is lack of natural prey species so it’s really important to have accurate information on what they’re eating for management plans and conservation initiatives.”

Weiskopf, who is supported by the National Science Foundation (NSF) EPSCoR program, and the ENWC department and works with data from Panthera– a global wild cat conservation group–and samples collected by Kachel, said that their research found that snow leopards’ diet consists mainly of large mammals. “When we looked at all the samples that we collected, we found that small mammals like hares and Pikas were not as important in snow leopard diet as we previously thought, and they were actually eating a lot more large mammals like Ibex and Argali.”

The problem with the snow leopards’ diet consisting mainly of these two species is that they are both in danger as well, with both being targets of hunting and poaching and Argali being classified as an endangered species.

“They’re competing with domestic livestock for the food resources in the area and so when you have less natural Ibex and Argali populations, the snow leopards will turn more to eating domestic livestock which creates problems with humans in the area,” said Weiskopf.

Weiskopf said that she is very thankful that she gets to work with Kachel and McCarthy, assistant professor in ENWC, on the project, saying that they both have been very supportive and helpful, even allowing her to work in the lab on her own which she said was a great learning experience.

She also said that the conference was a great experience because she got to listen to a lot of wildlife biologists talk about their respective projects and had the opportunity to present her own work.

As for her work with snow leopards, Weiskopf said that if she continues to study the species, she would love the opportunity to travel to central Asia to study them in the wild, something she might not have known about herself had she not gotten this opportunity.

“It wasn’t something that I thought about before. I didn’t think, ‘Oh, I really want to study snow leopards’ but it was definitely a really cool project to get involved in.”

Article by Adam Thomas

Share

Soil may harbor answer to reducing arsenic in rice

May 1, 2013 under CANR News

Drs. Harsh Bias & Janine Sherrier work together with bacteria resistant rice plants at the Greenhouse.Harsh Bais and Janine Sherrier of the University of Delaware’s Department of Plant and Soil Sciences are studying whether a naturally occurring soil bacterium, referred to as UD1023 because it was first characterized at the University, can create an iron barrier in rice roots that reduces arsenic uptake.

Rice, grown as a staple food for a large portion of the world’s population, absorbs arsenic from the environment and transfers it to the grain. Arsenic is classified as a poison by the National Institutes of Health and is considered a carcinogen by the National Toxicology Program.

Long-term exposure to arsenic has been associated with skin, lung, bladder, liver, kidney and prostate cancers, and low levels can cause skin lesions, diarrhea and other symptoms.

The risks of arsenic in rice were recently highlighted in the national press, when arsenic was detected in baby foods made from rice. In regions of the world where rice is the major component of the human diet, the health of entire communities of people can be negatively impacted by arsenic contamination of rice.

Arsenic may occur naturally in the soil, as it does in many parts of Southeast Asia, or it may be a result of environmental contamination. Despite the health risks arsenic in rice poses to millions of people around the world, there are currently no effective agricultural methods in use to reduce arsenic levels.

Sherrier, professor, and Bais, associate professor, are investigating whether UD1023 — which is naturally found in the rhizosphere, the layer of soil and microbes adjacent to rice roots — can be used to block the arsenic uptake. Bais first identified the bacterial species in soil samples taken from rice fields in California.

The pair’s preliminary research has shown that UD1023 can mobilize iron from the soil and slow arsenic uptake in rice roots, but the researchers have not yet determined exactly how this process works and whether it will lead to reduced levels of arsenic in rice grains.

“We have a bacterium that moves iron, and we want to see if creating an iron shield around the rice roots will slow arsenic movement into other parts of the plant,” Bais said.

Sherrier and Bais, who received a 2012 seed grant for the project from Delaware’s National Science Foundation Experimental Program to Stimulate Competitive Research (EPSCoR), ultimately want to determine how UD1023 slows arsenic movement into rice roots and whether it will lead to reduced levels of arsenic in the rice grains, the edible portion of the plant.

“That is the most important part,” Bais said. “We don’t know yet whether we can reduce arsenic in the grains or reduce the upward movement of arsenic towards the grain, but we’re optimistic.”

Bais says that, if successful, the project could lead to practical applications in agriculture.

“The implications could be tremendous,” he said. “Coating seeds with bacteria is very easy. With this bacteria, you could implement easy, low-cost strategies that farmers could use that would reduce arsenic in the human food chain.”

Article by Juan C. Guerrero

Photo by Kathy F. Atkinson

This article can also be viewed on UDaily.

Share

UD researchers show how beneficial soil bacteria can boost plant immunity

August 29, 2012 under CANR News

With the help of beneficial bacteria, plants can slam the door when disease pathogens come knocking, University of Delaware researchers have discovered.

A scientific team under the leadership of Harsh Bais, assistant professor of plant and soil sciences in UD’s College of Agriculture and Natural Resources, found that when pathogens attempt to invade a plant through the tiny open pores in its leaves, a surprising ally comes to the rescue. Soil bacteria at the plant’s roots signal the leaf pores to close, thwarting infection.

The fascinating defense response is documented in video and micrographs of live plants taken by confocal and scanning electron microscopes at UD’s Bio-Imaging Center at the Delaware Biotechnology Institute.

The research, which explored the interaction between the soil bacterium Bacillus subtilis and the laboratory plant Arabidopsis thaliana, is published in the August issue of The Plant Journal. The findings underscore both the importance of root-based processes in plant defense and the potential for bolstering plant immunity naturally through the emerging field of probiotics.

Postdoctoral researcher Amutha Sampath Kumar is the lead author of the journal article. In addition to Bais, the co-authors include postdoctoral researcher Venkatachalam Lakshmanan, researchers Jeffrey L. Caplan, Deborah Powell and Kirk J. Czymmek of UD’s Bio-Imaging Center, and Delphis F. Levia, associate professor of geography. The National Science Foundation, University of Delaware Research Foundation and Delaware Experimental Program to Stimulate Competitive Research (EPSCoR) provided funding for the study.

Millions of stomata, consisting of microscopic pores surrounded by guard cells, cover the above-ground parts of plants, from the stems to the flower petals. The pores resemble tiny mouths, or doors, which the guard cells open and close to allow carbon dioxide, oxygen, water and minerals in and out of the plant.

Pathogens also can slip through these stomata and begin infecting the plant. However, as Bais’s team confirmed, this invasion is halted when the beneficial bacterium Bacillus subtilis is present in the soil where the plant is rooted. The finding was based on tests of approximately 3,000 Arabidopsis plants inoculated with the foliar pathogenPseudomonas syringae pathovar tomato DC3000 (PstDC3000) during a year-long period.

When a foliar pathogen attacks, as shown in previous research by Bais and his group, the plant recruits Bacillus subtilis to help and facilitates its multiplication. The Bacillus subtilisbacteria bind to the plant’s roots and invoke abscisic acid and salicylic acid signaling pathways to close the stomata.

Abscisic acid and salicylic acid are both important hormones involved in plant defense. When a plant encounters adverse environmental conditions, such as drought, for example, abscisic acid triggers the stomata to shut tightly to prevent the plant from dehydrating.

In addition to ramping up plant disease resistance, the use of this rhizobacteria to promote drought tolerance in plants could be a very promising avenue, Bais notes.

“Many bacterial pathogens invade plants primarily through stomata on the leaf surface,” Bais says. “But how do plants fight off infection? In our studies of the whole plant, we see this active enlistment by Bacillus subtilis, from root to shoot.”

Strikingly, the research team’s data revealed that of different root-associated soil bacteria tested, only Bacillus species were effective in closing the stomata and for a prolonged period.

“We know only 1 to 5 percent of what this bug Bacillus subtilis can do, but the potential is exciting,” Bais notes, pointing out that there is increasing commercial interest in inoculating crop seeds with beneficial bacteria to reduce pathogen infection. “Just as you can boost your immune system, plants also could be supercharged for immunity.”

Article by Tracey Bryant

Photo by Ambre Alexander

This article can also be viewed on UDaily.

Share

EPSCoR seed grants awarded for environmental research

January 7, 2010 under CANR News

The Delaware EPSCoR office has awarded three seed grants to investigators whose projects address environmental challenges in Delaware.  CANR faculty members among researchers awarded. 

Click here for the full story on UDaily.

Share