Why You Ought to Be Concerned About Plant-Parastic Nematodes

If you like to eat a variety of foods and if you like to wear cotton, you ought to be concerned about plant-parasitic nematodes.

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.

What sparked his interest in nematology? While studying for his masters, he developed a keen interest in molecular biology and biotechnology. For his doctorate, he sought a lab where “I could do my PhD and learn more about cell and molecular biology.” He found that opportunity with Florian Grundler, a professor at the University of Natural Resources and Life Sciences (BOKU), Vienna, Austria.

“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.”

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