- Author: Kathy Keatley Garvey
And it has a University of California, Davis, connection.
An international team of 10 scientists, led by plant nematologist Shahid Siddique, a former research group leader at the University of Bonn, Germany, and now an assistant professor in the UC Davis Department of Entomology and Nematology, has discovered the role of a plant's endodermal barrier system in defending against plant-parasitic nematodes.
“We discovered that the integrity of the endodermis—a specialized cell layer that surrounds the vascular system and helps regulate the flow of water, ions and minerals--is important to restrict nematode infection,” said Siddique, who joined the UC Davis faculty in March after serving several years at the University of Bonn.
“We found that having defects in endodermis make it easier for parasites to reach the vascular cylinder and establish their feeding site. Although, this finding is a result of basic research, it opens new avenues to for breeding resistance against cyst nematodes in crops.”
The research, “Root Endodermal Barrier System Contributes to Defence against Plant‐Parasitic Cyst and Root‐Knot Nematodes,” is published in the July 19th edition of The Plant Journal.
Siddique collaborated with scientists from Germany, Switzerland and Poland: Julia Holbein, Rochus Franke, Lukas Schreiber and Florian M. W. Grundler of the University of Bonn; Peter Marhavy, Satosha Fujita, and Niko Geldner of the University of Lasuanne, Switzerland; and Miroslawa Górecka and Miroslaw Sobeczak of the Warsaw University of Life Sciences, Poland.
“Plant-parasitic nematodes are among the most destructive plant pathogens, causing agricultural losses amounting to $80 billion annually in the United States,” said Siddique. “They invade the roots of almond, tomato, beets, potato or soybeans and migrate through different tissues to reach the central part—the vascular cylinder--of the root where they induce permanent feeding sites.”
“These feeding sites are full of sugars and amino acids and provide the parasite all the nutrients they need,” Siddique explained. “A specialized cell layer called the endodermis surrounds the vascular system and helps regulates the flow of water, ions and minerals into and out of it. However, the role of endodermis in protecting the vascular system against invaders such as nematodes had remained unknown.”
In their abstract, the scientists noted that plant-parasitic nematodes (PPN) “cause tremendous yield losses worldwide in almost all economically important crops. The agriculturally most important PPNs belong to a small group of root‐infecting sedentary endoparasites that includes cyst and root‐knot nematodes. Both cyst and root‐knot nematodes induce specialized long‐term feeding structures in root vasculature from which they obtain their nutrients.”
“A specialized cell layer in roots called the endodermis, which has cell walls reinforced with suberin deposits and a lignin‐based Casparian strip (CS), protects the vascular cylinder against abiotic and biotic threats,” the researchers explained. “Until now, the role of the endodermis, and especially of suberin and the CS, during plant–nematode interactions was largely unknown.”
The research was funded by a grant from the German Research Foundation.
(Note: The Plant Journal is a peer-reviewed scientific journal of plant science published by Wiley-Blackwell for the Society for Experimental Biology. Established in 1991, the journal is published twice a month. Editor Lee Sweetlove says that the journal "provides a dynamic forum for the ever-growing international plant sciences research community and publishes in all key areas of plant biology.")
- Author: Kathy Keatley Garvey
And you ought to be interested in the exciting research that Shahid Masood Siddique, a new member of the UC Davis Department of Entomology and Nematology faculty, is doing.
Plant-parasitic nematodes are microscopic worms that extract water and nutrients from such host plants as wheat, soybeans, sugar beets, citrus, coconut, corn, peanuts, potato, rice, cotton and bananas. (See more from a list compiled by the Agricultural Research Services of the U.S. Department of Food and Agriculture or USDA-ARS.)
“They're one of the most destructive agricultural pests,” says Siddique, an assistant professor who joined the UC Davis Department of Entomology and Nematology last March. “The agricultural losses due to plant-parasitic nematodes reach an estimated $80 billion. The high impact of plant parasitic nematodes in economically important crops is not only due to the direct damage but also because of the role of some species as virus vectors.”
“In fact, a recent expert-based assessment of crop health lists nematodes among the most damaging pests and pathogens in different crops. In particular for soybeans, nematodes are the most damaging pests in the United States and around the world.”
Siddique, who served as a research group leader for several years at the University of Bonn, Germany, before joining the UC Davis faculty, says nematodes are troubling in other ways as well. “Although nematode-resistance varieties are available for various crops, there is an emergence of resistant-breaking population throughout the world. An example is the recent arrival of peach root-knot nematode in California, which has the potential to seriously harm many of region's important crops including almonds, peaches, eggplants, sugar beets and cucumber.”
Siddique was among a team of scientists from Bonn University and University of Missouri, who demonstrated the ability of parasitic nematodes to synthesize and secrete a functional plant hormone to manipulate the host system and establish a long-term parasitic interaction. PNAS published the research in August 2015. In a subsequent article headlined “Researchers Discover Key Link in Understanding Billion-Dollar Pests in Agriculture,” Science Daily called nematodes “a huge threat to agriculture, causing billions in crop losses every year …The discovery will help to develop crop plants that feature enhanced protection against this type of parasites.”
Born and reared in Multan, Pakistan, Siddique received two degrees in Multan: his bachelor of science degree from the Government College Bosan Road in 2001 and his master's degree in botany from the Bahauddin Zakariya University in 2004. Then it was off to Vienna, Austria to receive his doctorate in 2009 in agriculture and biotechnology from the University of Natural Resources and Life Sciences.
“His group was working on understanding the molecular aspects of plant-nematode interaction,” Siddique recalled. “In particular, they were using microarrays to study the changes in gene expression in plants upon nematode infection. I found the work very interesting and joined his lab.”
Nematodes did not immediately trigger his interest. “They have a complicated life cycle and infection pattern,” he points out. “Also, it is not yet possible to genetically transform plant-parasitic nematodes. So, I was mostly focusing on plants, which are more amenable to genetic manipulations. Then I gradually started to realize that how fascinating it is to work with nematodes, how they have mastered the ability to manipulate the defense and developmental pathways of their host.”
By the time he completed his doctorate, “I was completely infected by nematodes.” He still is.
What drew him to UC Davis? “High academic reputation in field of agriculture was the main factor that drew me to UC Davis,” Siddique says. “Ethnic diversity and liberal culture of golden state are some of the other factors that contributed to my decision to move to UC Davis.”
“For the next six months, I will be focusing on establishing a state-of-the art nematology lab here at UC Davis. This includes buying equipment, hiring the staff, establishing the protocol, and multiplying the nematode culture. In terms of research, my mid-term goal is understanding the plant immune responses to nematode infections. In long-term, I would like to use this knowledge to produce durable and broad-spectrum resistance in crops.”
“Another area where I will be focusing is development of molecular diagnostic tools for plant-parasitic nematodes from soil,” Siddique says. “I will be particularly focusing on nematodes that are relevant to California agriculture. Lastly, I am highly interested in understanding the mechanism of biocontrol of plant-parasitic nematodes. I expect that this will help in understanding why application of microbial biocontrol is so inconsistent.”
Siddique describes himself as “a result-oriented person and I am comfortable leading a large research team. At the same time, I like to delegate the responsibilities. My working style is collaborative and I believe on open and frank communication.”
In his leisure time, he enjoys cooking, outdoor adventures and watching documentaries. What would people be surprised to know about him? “I am an introvert,” he says. “A couple of other things: I like super spicy food and my favorite game is cricket. And oh, yes, I don't like ice-cold water.”
Siddique is currently seeking “undergraduate and graduate students to work on a number of exciting projects.”
“California is a beautiful place to live,” Siddique says, “and Davis is a perfect place to work on nematodes. So, for those interested in working with nematodes, drop me an email at ssiddique@ucdavis.edu.”
Related Links:
- “Worm Subverts Plant Attack,” The Scientist, April 3, 2014
- “Researchers Discover Key Link in Understanding Billion-Dollar Pests in Agriculture,” Science Daily, Sept. 29, 2015
- “Arabidopsis Leucine-Rich Repeat Receptor–Like Kinase NILR1 Is Required for Induction of Innate Immunity to Parasitic Nematodes,” PLOS Pathogens, April 13, 2017
- Author: Kathy Keatley Garvey
It's true.
The U.S. Department of Agriculture's (USDA) Agricultural Research Service (ARS) and Pheronym, a company in Alachua, Fla., that develops and produces nematode pheromones, have announced plans to send nematodes (small round worms) to the International Space Station as early as this year.
The news, announced Feb. 20 on the ARS website, may have been overlooked by many ("What's a nematode?") but not by nematologists and other scientists.
The headline: "Starship Nematode."
"The mission represents a look into the future where food crops will be grown in space," according to writer Sharon Dunham. "The goal is to develop environmentally friendly methods for space travel that are not harmful to humans," she wrote. "This will be the first biological control experiment in space."
She went on to relate that experiment will "test the movement and infection behavior of beneficial nematodes (also called entomopathogenic nematodes or EPNs) that control a wide array of insect pests in agriculture." ARS research entomologist, David Shapiro-Ilan at the Fruit and Tree Nut Research Station in Byron, Ga., is co-project director of the experiment.
Nematodes, Dunham said, are "environmentally friendly alternatives to broad spectrum chemical insecticides and are also safe to humans and other nontarget organisms. One fascinating aspect of the EPN biology is that the nematodes kill their insect pest hosts with the aid of symbiotic bacteria that are carried in the nematode gut."
Nathan Augustus Cobb (1859-1932), the "father of nematology in the United States," had this to say about a world without nematodes.
"In short, if all the matter in the universe except the nematodes were swept away, our world would still be dimly recognizable, and if, as disembodied spirits, we could then investigate it, we should find its mountains, hills, vales, rivers, lakes, and oceans represented by a film of nematodes. The location of towns would be decipherable, since for every massing of human beings, there would be a corresponding massing of certain nematodes. Trees would still stand in ghostly rows representing our streets and highways. The location of the various plants and animals would still be decipherable, and, had we sufficient knowledge, in many cases even their species could be determined by an examination of their erstwhile nematode parasites."
In fact, nematodes seem totally destructible.
- Author: Kathy Keatley Garvey
The event, free, family friendly and educational, is always held on Presidents' Day weekend. It's billed as a time "to meet and talk with UC Davis scientists from undergraduate students to staff to emeritus professors and see amazing objects and organisms from the world around us."
The times will be staggered. Some collections will be open from 9 a.m. to 1 p.m., and others, from noon to 4 p.m. Here's a list of what you can see, with links to their websites:
Room 1124 and hallway of the Academic Surge Building, Crocker Lane
Greenhouses along Kleiber Hall Drive
340 Equine Lane, off Old Davis Road
Sciences Laboratory Building, off Kleiber Hall Drive
Häagen-Dazs Honey Bee Haven (Noon to 4 p.m.)
Bee Biology Road, off Hopkins Road (take West Hutchison Drive to Hopkins (take West Hutchison Drive to Hopkins)
Marine Invertebrate Collection (not linked) (Noon to 4 p.m.)
Sciences Laboratory Building, off Kleiber Hall Drive
Museum of Wildlife and Fish Biology (9 a.m. to 1 p.m.)
Room 1394, Academic Surge Building, Crocker Lame
Paleontology Collection (9 a.m. to 1 p.m.)
Earth and Physical Sciences Building, 434 LaRue Road
Phaff Yeast Culture Collection (9 a.m. to 1 p.m.)
Robert Mondavi Institute of Wine and Food Science, 392 Old Davis Road, on campus
Viticulture Enology Culture Collection (9 a.m. to 1 p.m.)
Robert Mondavi Institute of Wine and Food Science, 392 Old Davis Road, on campus
Want a peek at what happened last year? See the YouTube video, the work of UC Davis student Alexander Fisher-Wagner.
There will be plenty of attractions for youngsters, including the insect petting zoo at the Bohart Museum; dinosaur bones at the Paleontology Collection; carnivorous plants at the Conservatory; Vegemite and Kombucha (to eat!) at the Yeast Collection; demonstrations of eagles and hawks and other birds at the Raptor Center; prehistoric tool demonstrations (flint knapping, atlatl throwing) at tje Anthropology Collection; leaf rubbing and olive wreath crown making at the Arboretum; insect vacuum for observation at the Bee Haven, and pine cone petting zoo at the Herbarium.
Yes, you can pet stick insects at the Bohart Museum and pet pine cones at the Herbarium.
Meanwhile, you can find more information on the Biodiversity Museum Day website. (More information is pending)
/span>- Author: Kathy Keatley Garvey
Quick question:
What was diagnostic parasitologist Lauren Camp of the UC Davis Veterinary Medical Teaching Hospital wearing on her head as she talked about the nematode collection last Saturday at the seventh annual UC Davis Biodiversity Museum Day?
“The hookworm in that image is a parasite of dogs,” explained Camp, who received her doctorate in entomology in 2016 from UC Davis, studying with major professor Steve Nadler, chair of the Department of Entomology and Nematology. “This nematode lives in the small intestine of dogs, and is pretty small, at around 14-16 mm. Dogs can have no symptoms from this parasite, but the parasite can be fatal in some cases. Some of the hookworm samples I showed on Saturday were red because hookworms eat blood from their hosts in addition to eating the intestinal lining. Importantly, Ivana Li made the hat for me using papier mache!”
That would be entomologist Ivana Li, a UC Davis biology lab manager who received her bachelor's degree in entomology from UC Davis in 2013.
Among nematologists staffing the collection, displayed from 1 to 4 p.m. in the Sciences Laboratory Building, were graduate students Corwin Parker and Chris Pagan, who study with major professor Steve Nadler.
Camp, who hails from rural northern Indiana, first became interested in parasites as an undergraduate student at the University of Chicago, where she received her bachelor's degree in biology in 2005. She went on to earn her master's degree in biology from Wake Forest University in 2007 and her doctorate from UC Davis in December 2017. Her doctoral research focused on the genetic characterization of raccoon roundworm, a zoonotic nematode, in North America.
Camp joined the Clinical Diagnostic Laboratories Parasitology Lab in August 2017. Her responsibilities include looking through feces to find and identify parasites. “Many of these parasites are nematodes,” she points out.
"My specific interest in nematode parasites developed when I read some of Dr. Nadler's work on the evolutionary relationships of nematodes for an invertebrate biology class," she related.
Nematologists are accustomed to answering "What's a nematode?"
In one word, "worms."
“Nematodes are an amazing phylum of organisms--they exist in almost every known environment on the planet, and different species eat everything from bacteria and fungi to plant and animal tissue," Camp told us back in 2017, prior to setting up a display at the Bohart Museum of Entomology open house on Parasite Palooza. "I find parasites particularly fascinating, because they are dependent on another organism (or organisms) for part or all of their life cycle."
Camp appeared Sunday, Jan. 22, 2017 on Good Day Sacramento's "Parasite Palooza" show with entomologist Jeff Smith, curator of the moth and butterfly specimens at the Bohart Museum of Entomology. They shared and showed specimens and live insects. Camp mentioned a 30-foot-long whale nematode. (See http://gooddaysacramento.cbslocal.com/video/category/spoken-word-good-day/3610653-parasite-palooza/). Her public service activities also include speaking to Capital Public Radio. (See http://www.capradio.org/88726.)