An attempt to illustrate cell orientation

Cells can use miRNAs to as a signal for their position within a plant.

Plants use miRNAs to pass signals between cells. But cells can’t just let anything in or out, so how do miRNAs get around?

miRNAs are useful molecules for plants. These small parcels of RNA pass along signals between cells. They move through plasmodesmata, microscopic channels through cell walls, and through the phloem to help cope with stresses. In a study published in Nature Communications Damianos Skopelitis and colleagues show that miRNA mobility is precisely regulated through a gating mechanism polarised at defined cell–cell interfaces. By polarising the miRNA, the plant cells know which side of the cell is facing toward the stem and which side is facing away.

An attempt to illustrate cell orientation
Image: Canva

The gating plays an important role in miRNA signalling. The authors state: “The gating of miRNA mobility allows for selectivity in long-distance signalling. The polarised regulation of miRNA mobility at the phloem of the central vasculature generates directional cell-to-cell movement, with miRNAs moving out but not into the phloem poles. Consequently, miRNAs not produced or amplified in phloem tissues of the shoot are restricted from moving long distance into the root. Thus, the gate-keeping mechanism regulating miRNA mobility at the central vasculature creates a movement barrier that ensures some small RNA-mediated signalling responses are contained while permitting others to be propagated systemically.”

This selectivity means that small RNAs can be used as local positional signals or to aid signals throughout an organism.

Dale Maylea

Dale Maylea was a system for adding value to press releases. Then he was a manual algorithm for blogging any papers that Alun Salt thinks are interesting. Now he's an AI-assisted pen name. The idea being telling people about an interesting paper NOW beats telling people about an interesting paper at some time in the future, when there's time to sit down and take things slowly. We use the pen name to keep track of what is being written and how. You can read more about our relationship with AI.

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