All over the world, huge quantities of crop protection agents are sprayed to control potato blight (Phytophthora infestans). The mechanisms of resistance of potatoes need to be better understood to make growing this crop more sustainable. Researchers of Wageningen University & Research together with their colleagues in Tübingen and Norwich have now taken an important step. Their research has been published in the journal Science.
“There is a continuous ‘arms race’ between the potato plant and Phytophthora,” says Vivianne Vleeshouwers, a plant scientist at WUR. The plant fiercely defends itself. An invasion of the “fungus” (actually an oomycete) immediately triggers a number of defense responses, such as making part of a leaf die off in a controlled manner to stop the advance of the disease. However, Phytophthora is able to repeatedly bypass these defenses by means of mutating.
To defend itself the first thing the plant has to do is recognize the pathogen. “The plant has receptors for this, a kind of antennas. These bind tiny pieces of Phytophthora protein, which is the signal that something is wrong. This is when the defense responses kick in. So it is very important that the plant can actually detect the disease and has the right receptors in place to activate its defenses,” says Vleeshouwers.
These receptors are located either inside or on the outside of the cell. Receptors inside the cell are encoded by specific R genes (R stands for resistance), and potato breeders take advantage of these. They develop resistant varieties by selecting for these R genes. However, the problem is that the Phytophthora manages to break through that resistance, time and again.
“Much less is known about the receptors on the outside, on the cell surface, the PRR receptors. These receptors drive more general immune responses,” Vleeshouwers says. Plant breeders are currently focusing their attention on R genes, but more fundamental research is required to be able to benefit from less specific defense responses by the PRR.
2023-09-11 11:24:02
Post from phys.org