Natures wonders: Plant awareness (Introduction)

by David Turell , Saturday, January 20, 2018, 17:55 (2497 days ago) @ dhw

A new study of how plants are aware of the world and what might affect them:

https://www.sciencedaily.com/releases/2018/01/180119190358.htm

"Plants lack eyes and ears, but they can still see, hear, smell and respond to environmental cues and dangers. They do this with the aid of hundreds of membrane proteins that sense microbes or other stresses. Researchers now have created the first network map for 200 of these proteins. The map shows how a few key proteins act as master nodes critical for network integrity, and the map also reveals unknown interactions.

"Now, an international team of researchers from four nations... has created the first network map for 200 of these proteins. The map shows how a few key proteins act as master nodes critical for network integrity, and the map also reveals unknown interactions.

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"The novel comprehensive interaction network map focused on one of the most important classes of these sensing proteins -- the leucine-rich repeat receptor kinases, or LRR-receptor kinases, which are structurally similar to human toll-like receptors.

"The LRR-receptor kinases are a family of proteins in both plants and animals that are largely responsible for sensing the environment. In plants, they have an extracellular domain of the protein, extending beyond the cell membrane, which can recognize chemical signals, such as growth hormones or portions of proteins from pathogens. The receptor kinases then initiate responses to these signals inside the cell, using an intracellular domain of the protein.

"The model plant Arabidopsis thaliana contains more than 600 different receptor kinases -- 50 times more than humans -- that are critical for plant growth, development, immunity and stress response. Until now, only a handful had known functions, and little was known about how the receptors might interact with each to coordinate responses to often-conflicting signals.

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"The Nature study included two major surprises, says Adam Mott, Ph.D., University of Toronto. LRR-receptor kinases that have small extracellular domains interacted with other LRR-receptor kinases more often than those that have large domains. This suggests that the small receptor kinases evolved to coordinate actions of the other receptors. Second, researchers identified several unknown LRR-receptor kinases that appear critical for network integrity.

"The most important one, dubbed APEX, was predicted to cause severe disruptions to the rest of the network if removed. Researchers found that removal of APEX, and several other known LRR-receptor kinases, indeed did impair plant development and immune responses, even though those responses are controlled by receptor kinases several network steps away from the APEX node."

Comment: It is not surprising plants have these automatic molecular mechanisms to sense the outside world. They must be able to defend themselves to survive. That some plants have more kinases than humans is that we have other methods of sensation at our command. Note that kinases are giant enzymes, which always raises the question of how did chance evolution discover such complex molecules? Supplied by God.