Plant/animal hybrid proteins can help crops ward off disease

A new biological mashup just dropped.

“Pikobodies” bioengineered immune system proteins that are part plant and part animal could help flora better fend off disease, researchers report on March 3. Science. Protein-engineered hybrids of animals with uniquely flexible immune systems harness the ability of plants to fight emerging pathogens..

Flora typically rely on the body’s barriers to keep disease-causing microbes at bay. If something unusual happens inside the plant, internal sensors sound the alarm and the infected cells die. But when pathogens evolve ways to beat these defenses, plants can’t adapt in real time. The adaptive immune system of animals can make an abundance of antibodies in material exposed to the pathogen for weeks.

In a proof-of-concept study, scientists modified one plant’s internal sensor to mimic animal elements. The approach harnesses the power of the adaptive immune system to provide virtually unlimited adaptations to attacking and invading plants, says plant immunologist Xinnian Dong, a Howard Hughes Medical Institute researcher at Duke University, who was not involved in the work.

Crops in particular can benefit from more adaptive immune systems, since many farms grow fields full of one type of grass, says Dong. In nature, diversity can protect vulnerable plants from pathogenic diseases and pests. The bottom is more like a buffet.

Researchers are fine-tuning plant disease resistance genes, but finding the right genes to eat could take more than a decade, says plant pathologist Sophien Kamoun of the Sainsbury Laboratory in Norwich, England. He and his colleagues wanted to know if a plant protection approach could be obtained from animal-inspired solutions.

To create the picobodies, the team mixed antibodies from llamas and alpacas with a protein called Pik-1 that was found in the cells Nicotiana benthamianacloser to the tobacco plant. Pik-1 typically encodes a protein that helps the deadly blast fungus infect plants (SN: 7/10/17). For this experiment, the animal’s antibodies were engineered for fluorescent proteins

The team found plants with dead picobody cells exposed to fluorescent proteins from sheaths in dead leaves. Of the 11 versions tested, four were non-toxic to leaves and cells unless the picobodies were attached to specific proteins to which they were intended to bind.

In addition, picobodies can be arranged to invade plants in more than one way to invade a foreigner. That technique could be useful for hitting pathogens with the easy ability to learn some immune responses from multiple angles.

With the idea, it’s possible to use picobodies “against any pathogen we’re looking for,” Kamoun says. However, not all pikobody combos met in the tests. “It’s hit or miss,” he said. “We don’t need any basic knowledge to improve bioengineering.”