Update on Interplant Internet
One of the early “amazing” stories reported in these pages concerned the startling observation that plants use a kind of “email” system in their own interplant “internet” (see 07/13/2001). What has been learned in the nine years since that story appeared? Quite a lot, and another fascinating article about plant communication appeared this week in Science Daily. Scientists at Duke, Cornell and the Universities of Helsinki and Uppsala confirmed that micro-RNAs are engaged in two-way communication as part of gene regulation between cells. A Duke team member said, “To our knowledge, this is the first solid evidence that microRNAs can move from one cell to another.” According to the article, this adds to the list of molecules involved in communication: hormones, proteins, and now micro-RNAs.
The packets of information stored in these molecules regulate how tissues and organs are developed in leaves, roots and organs. Listen to one example of how proteins control a waterproofing layer:
They also add a new element to the already complex interplay in Arabidopsis roots between two proteins, known as Scarecrow and Short-root, that Benfey’s team had described in earlier work. Those proteins interact and restrain one another to allow the assembly of a waterproofing layer of cells that ultimately enables plants to control precisely how much water and nutrients they take in.
The researchers now show that Short-root moves from cells in the plant’s inner vasculature out into the waterproofing endodermis that surrounds it to activate Scarecrow. Together, those two transcription factors (genes that control other genes) activate microRNAs, known as MIR165a and 166b. Those microRNAs then head back toward the vascular cells, meeting and degrading another transcription factor (called Phabulosa) as well as other regulatory factors along the way.
The two-way communication works across cell borders. The “internet” nature of these between-cell signals is essential for correct patterning of tissues, the article explained. Susan Haynes of NIH said, “This study provides important insight into how cells communicate positional information to orchestrate the complex process of tissue and organ development.”
The article concluded by noting that the specific instances discovered here are most likely indicators of a general phenomenon that will be noticed throughout biology. Duke systems biologist Philip Benfey tacked on an evolutionary comment:
He said there’s also reason to think that the specific regulatory interactions they’ve uncovered were key in the evolutionary transition from single-celled algae to land plants.
“ “Formation of vascular tissue with a surrounding endodermal layer that acts as waterproofing was a key milestone in the evolution of land plants,” Benfey said. “Without a tube to conduct water, you can’t grow a tree or a sunflower.”
This comment amounted to a requirement without a specification.
It was really painful to reproduce Benfey’s Darwin malapropism in this otherwise fascinating entry. It’s kind of like having to endure someone telling an insensitive joke or belching during a speech. Let’s deal with it quickly and move along. This is another indiscretion from an evolutionist who has not learnt good manners. One cannot simply assume that miracles will occur on cue, simply because Mr. Darwin needs them. A single-celled alga needs a tube to conduct water. Yes, the tube needs a waterproofing layer, too. Without these requirements being met, you can’t grow a tree or sunflower. Fine; understood. But Mr. Benfey, who is going to snap his fingers and call for Tinker Bell to zap the alga with her mutation wand by your script? How many gazillion algae will have to die before one struggles to get the internet right and the email system working? Remember, you don’t believe in miracles or end-goals, so this all has to happen by an undirected process with each and every step producing survival value. LOL, LOL (Lots of Luck, Laugh out Loud).
Ahem; back to our regularly scheduled celebration. Ladies and gentlemen, we call attention to this fine discovery by the teams at Duke, Cornell, Uppsala and Helsinki, and thank them for dazzling us with insights into another living design that predated our own. Here we thought we invented the internet, only to find it was there long before our feeble attempts at two-way packetized communication. My, what will we discover next!