Plant immunity; fighting off fungus (Introduction)

by David Turell , Saturday, December 30, 2023, 19:31 (120 days ago) @ David Turell

Implant some RNA:

https://www.sciencedaily.com/releases/2023/12/231221012831.htm

UC Riverside scientists have discovered a stealth molecular weapon that plants use to attack the cells of invading gray mold.

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A new paper in the journal Cell Host & Microbe describes how plants send tiny, innocuous-seeming lipid "bubbles" filled with RNA across enemy lines, into the cells of the aggressive mold.

Once inside, different types of RNA come out to suppress the infectious cells that sucked them in.

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Previously, Jin's team discovered that plants are using the bubbles, technically called extracellular vesicles, to send small RNA molecules able to silence genes that make the mold virulent.

Now, the team has learned these bubbles can also contain messenger RNA, or mRNA, molecules that attack important cellular processes, including the functions of organelles in mold cells.

"These mRNAs can encode some proteins that end up in the mitochondria of the mold cells. Those are the powerhouses of any cells because they generate energy," Jin explained.

"Once inside, they mess up the structure and function of the fungal mitochondria, which inhibits the growth and virulence of the fungus."

It isn't entirely clear why the fungus accepts the lipid bubbles.

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The strategy is an efficient one for the plants, because one mRNA molecule can have an outsized effect on the fungus.

"The beauty of delivering mRNA, instead of other forms of molecular weapons, is that one RNA can be translated into many copies of proteins. This amplifies the effect of the mRNA weapon," Jin said.

Mold also uses these same lipid bubbles to deliver small, damaging RNAs into the plants they are infecting to suppress host immunity, an ability developed as part of a co-evolutionary arms race.

Comment: part of the design must include a mechanism that prevents these mRNA's from damaging the plant itself. Stepwise development could result in severe mortality during the process. Direct design answers the problem.