Evolution: bacteria's' role in plant biomes (Introduction)

by David Turell , Monday, April 13, 2020, 19:47 (1683 days ago) @ David Turell

We are finding that controlled beneficial biomes are everywhere. New plant research:

https://www.sciencedaily.com/releases/2020/04/200413103534.htm

"Michigan State University scientists show how plant genes select which microbes get to live inside their leaves in order to stay healthy.

"This is the first study to show a causal relationship between plant health and assembly of the microbial community in the phyllosphere -- the total above-ground portions of plants. The work suggests that organisms, from plants to animals, may share a similar strategy to control their microbiomes.

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"'If everything is allowed to grow in the plants, it would probably be a mess. We want to know if the numbers and types of microbes matter, if there is a perfect composition of microbes. If so, do plants have a genetic system to host and nurture the right microbiome?"

"It seems plants do. The newly discovered mechanism involves two genetic networks. One involves the plant immune system and the other controls hydration levels inside leaves. Both networks work together to select which microbes survive inside of plant leaves.

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"'Very few people have grown a sterile plant in sterile, organic-rich material," He said. "Our system uses a peat-based soil-like substrate, basically greenhouse potting soil. We use heat and pressure to kill all the germs in the soil, and the plants can grow under this germ-free condition."

"Researchers can then introduce microbes in a controlled fashion, into this environment.

"'You can add one, two, or even a community of bacteria," He said. "In our study, we extracted a community of bacteria from dysbiotic, or sick, plants and introduced them to our healthy plants, and vice-versa. We found that both the microbiome composition and the plant genetic systems are required for plant health."

"For example, a plant with defective genetics could not take advantage of a microbiome transplanted from a healthy plant. The microbiome slowly reverted to the state that caused sickness.

"On the other end, a healthy plant exposed to a sick plant's microbiome also suffered. Although it had the genetic tools to select the right microbes, microbe availability was limited and abnormal. The plant couldn't fix the situation.

"It turns out that increased microbiome diversity correlates with plant health. Somehow, plant genes are gatekeepers that encourage this diversity.

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"In the sick plants, proteobacteria strains -- many of which are harmful to plants -- jumped from two-thirds the composition of a healthy microbiome to 96% in the abnormal population. Fermicutes strains, many which may be helpful to plants, went down in numbers.

"'Perhaps, when the population of microbiome is abnormally higher in that sick plant, the microbes are physically too close to each other," He said. "Suddenly, they fight over resources, and the aggressive -- in this case harmful -- ones unfortunately win. Healthy plants seem to prevent this takeover from happening."

"The study is yet another example of how diversity is important to support healthy living systems. Each type of microbe might impart different benefits to plants, such as increased immunity, stress tolerance or nutrient absorption."

Comment: Once again we see how important bacteria are in the scheme of livings things and their continuing health. God knows what He is doing, despite dhw's doubts. We wondered, early on, why bacteria survived all the extinctions and are still here. they were meant to be a major help all along. God knows His plans for the future, from the beginning.