Natures wonders: new plant fungus symbiosis studied (Introduction)

by David Turell , Friday, January 26, 2024, 02:10 (301 days ago) @ David Turell

A type of fungi known as arbuscular mycorrhizal (AM) fungi:

https://phys.org/news/2024-01-underground-network-decoding-dynamics-fungal.html

"AM fungi live within plant root cells, forming a unique alliance with their plant hosts. This relationship is more than a simple coexistence; it involves a complex and critical exchange of nutrients essential for fungal survival and highly beneficial for the plant.

"Researchers at the Boyce Thompson Institute (BTI) have uncovered the roles of two proteins, CKL1 and CKL2, which are active only in the root cells containing the AM fungi. These two proteins belong to a larger family of proteins known as CKLs, whose functions in the plant have yet to be fully understood.

"'The closest relatives of the CKL family are proteins, called CDKs, that control the plant cell cycle and are located in the nucleus of the cell. Surprisingly, the CKL1 and CKL2 proteins have evolved a different role than CDKs—they do not control the cell cycle. They are tethered to the membranes of the root cell, including a membrane that surrounds the fungus," said Dr. Sergey Ivanov, a post-doctoral researcher at BTI and first author of the study.

"The scientists found that these CKL proteins are critical for the fungi's survival within plant roots. They play a pivotal role in controlling the flow of lipids (fats) from the plant to the fungi, a process essential for the fungi's nourishment. Without these proteins, key genes that manage this lipid transfer are not activated, starving the fungi.

"The research also uncovered a complex web of interactions involving several receptor kinase proteins. One of these kinases is known for its role in allowing the AM fungus to penetrate the root's outer layer. The researchers discovered that this same kinase adopts a new role deeper within the root, where it partners with CKL proteins, potentially to initiate the flow of lipids to the fungus.

"Surprisingly, while CKL proteins are vital for controlling lipid flow, they don't manage the entire symbiotic lipid pathway. Instead, they control genes responsible for the start and end of this pathway. Meanwhile, a key protein operating in the middle of this pathway, RAM2, is activated by a different regulator, RAM1. For full-scale lipid production to occur, both the CKL and RAM1 pathways must be active."

Comment: fungi are so important to plant life. Here again, as with bacteria, fungi can cause severe infections. The balance of great good to occasional mistakes is part of the life we are given. Balance that with no life at all.