March 29, 2024

How do alpacas protect plants from disease?

Closer to the dream of designer resistance genes

Plants have a relatively simple immune system. On the surface of plant cells are special receptor proteins that can recognize general characteristics of pathogens, such as the bacterial cell wall. Within the cell, they have additional receptors that respond to molecules secreted by certain germs. If a plant cell detects such clues, it dies, saving the rest of the plant. However, plant pathogens often develop and bypass these receptors.

Therefore, developing designer resistance genes that can be produced as quickly as pathogens emerge is a plant biotech’s dream. One method is to modify the gene for a plant immune receptor so that it recognizes certain harmful molecules. However, this requires precise knowledge of both the receptor and its binding site on the pathogen.

Instead, Sophien Kamoun, study leader and molecular biologist at Sainsbury’s lab, and her team used the animal’s immune system to make changes to the receptor. When animals contract a new disease, they produce billions of antibodies, each one slightly different. The immune system ultimately selects those that fight the invader best and manufactures them in large quantities. Camels, which include alpacas, camels, and llamas, are capable of creating highly compact antibodies, so-called nanobodies, against almost any molecule. The researchers linked such a nanogene to a gene for an intracellular immune receptor in a model plant.