[radarsat1]

> Perhaps even more surprising than the long intervals at which they flower is the fact that all plants of the same stock of bamboo will bloom at the same time, and then die, no matter where they are in the world.

> Although the mechanism has yet to be explained by science, many believe there is some kind of natural “alarm clock” in the plant’s cells causing the behavior.

That is amazing. I'm having a hard time imagining how that could even be possible, for DNA to have an "absolute" sense of time. Some kind of day/night/time of year "counting" mechanism?

[puzzlingcaptcha]

There are some other examples like that in biology, my favourite being 13- and 17-year periodic cicadas [1] with one theory being that a prime number was selected for during evolution to make it more difficult to synchronize with predator life cycles.

Counters in biology are also a thing, for example Hayflick limit [2] which is a number of times a single cell can divide before it dies (partially explained by telomere shortening due to particularities of replication of the lagging DNA strand 3). What is interesting here is that plants from the same clone grown in different climates likely grow at different rates so the counter must be decoupled from cell division. Perhaps accumulation of some metabolite that adds up every season triggers it at some threshold?

[1] https://en.wikipedia.org/wiki/Periodical_cicadas [2] https://en.wikipedia.org/wiki/Hayflick_limit [3] https://en.wikipedia.org/wiki/Telomere#Shortening

[jansan]

I thought that circadas thing was made up for the series Silicon Valley:

https://www.youtube.com/watch?v=kxh2X6NjuhY

[scott_s]

It was not. https://en.wikipedia.org/wiki/Periodical_cicadas

[wbl]

Coming from NJ I can safely say cicadeads are not made up.

[komali2]

I promise I am not trying to be an asshole here - is there some joke I'm missing about both of your spelling of cicadas?

[Terretta]

In southeastern seaboard US states, some folks called them cicadas, some called them katydids, and some got the syllables confused and said things like katydeads or similar. Some people claimed the name depended on where you’re from.

But they’re not the same:

https://zippyfacts.com/what-is-the-difference-between-katydi...

[wbl]

I had thought Cicadiads are the waves of cicadas. Turns out people say brood.

[sdenton4]

I imagine its just that cicadas - when they finally show up by the millions - also die by the millions, and leave little crunchy carcasses EVERYWHERE.

[sdrg822]

I also have been wondering whether I am out of the loop on some joke...

[mmanfrin]

Even if it were made up, that bit of lore has been around much longer than the show.

[teej]

Life was loud and very buggy in 2004 when Brood X emerged on the east coast US.

[JudgeWapner]

[4] https://www.barrierreef.org/the-reef/the-facts/creature-feat...

[tdaltonc]

In undergrad I made models of oscillator genes. They allow for digital cycle counting. They can also be chained to give base-2 counting systems. For example, cycle of gene A turns on gene B be turns off itself, one cycle of gene B turns on gene C, turns on gene A and turns off itself, etc. This would give you a binary counter. Assuming they all oscillate the same frequency, you would get something like:

+-------+---+---+---+---+

| Cycle | A | B | C | D |

+-------+---+---+---+---+

| 1 | 1 | 0 | 0 | 0 |

+-------+---+---+---+---+

| 2 | 0 | 1 | 0 | 0 |

+-------+---+---+---+---+

| 3 | 1 | 0 | 1 | 0 |

+-------+---+---+---+---+

| 4 | 1 | 1 | 1 | 0 |

+-------+---+---+---+---+

| 5 | 0 | 0 | 0 | 1 |

+-------+---+---+---+---+

And then if gene D triggers flowering: Tada! you would get one flowering every 5 cycles. In practice things are never this simple. The gene expression rules are not that straightforward, the genes do not all express in the same cycles, you need some mechanism to keep things in sync between cells and plants etc. But the simplified model shows how powerful oscillator genes with expression switches can be.

https://www.wikiwand.com/en/Oscillating_gene

[radarsat1]

Super interesting, thanks for that. I guess a synchronization mechanism could just be the cycle of sunlight.. I'm amazed though.

[tdaltonc]

The sun is a great sync signal for diurnal cycles. And something about temp could be used for annual cycles. I would be very interested to know if you cloned a cicada (for example) and put it out in the wild, would it be able to get in sync with the wild ones or wound the clones clock stay out of phase?

[yorwba]

Is there any particular reason you link to Wikiwand instead of https://en.wikipedia.org/wiki/Oscillating_gene ? The content appears to be the same.

[tdaltonc]

No. I think the wikiwand site looks nicer so my browser is set to auto redirect. For me, that's just how wikipedia looks now, so I forget that posting those links will look weird and sometime dodgy to other people.

[crygin]

I recently learned about beech masting in NZ, which has a similar (but much more frequent) blooming cycle based on the difference between successive summer temperatures: https://www.landcareresearch.co.nz/publications/newsletters/...

"According to their ‘delta T’ (ΔT) model, the likelihood of masts by several species, including beech and tussocks, is positively correlated with the difference between average summer temperatures in successive years: a high positive value of ΔT (i.e. last summer warmer than the preceding summer) corresponds to a high likelihood of a mast in the coming year."

I'd always imagined that these types of events involved pheromone-type signaling, but this is kind of a cool way to do distributed consensus based on external signaling.

[pontifier]

I saw an interesting Ted talk a few years ago about quorum sensing in bacteria.

Here's my recollection:

Essentially a single bacteria can't make you sick, and if it tried, it's so small that it would have no effect. Triggering a collective effect becomes critical for them to cause disease. Disrupting quorum sensing might be a way to fight otherwise resistant bacteria.

[cmrdporcupine]

I don't know the exact mechanism (it sounds like nobody does) but remember these are clonally propagated (until they flower, which I presume creates seeds). So most of the entire population is actually one genetic "individual". So the 'alarm clock' must be tied to the original genetic signature.

[Ma8ee]

No, there's no reason to believe they are only one genetic individual. Just because many are clones, there's no reason to believe they all are clones from the same original plant.

[jonknee]

"all plants of the same stock of bamboo" makes it sound like this would indeed be from the same original plant.

[_underfl0w_]

I'm no expert here, but that does seem to be a logical interpretation of what was written.

OTOH, the author seems distinctly... less scientifically inclined than the bulk of commenters here. They may have simply meant "of the same genus".

[deepzn]

Is it also for bamboos of different ages, like if I planted a bamboo yesterday, and today was when they all bloomed, would that bloom? The article mentioned an owner planting one in 2008 and it blooming now? So, that would mean the natural clock isn't about how old they get, but for a certain date-time or period or some weather conditions perhaps?

[nkrisc]

But is that bamboo you're planting really a different age? Bamboo reproduces clonally, right? So isn't that bamboo you're planting really part of an older stock? So its clock started ticking when its ancestor clone first began growing.

[pvaldes]

> if I planted a bamboo yesterday, and today was when they all bloomed, would that bloom?

In principle Yes but is an extreme example. Is possible also that the plant just will die before if roots are damaged in the process and their reserves are depleted.

[hinkley]

There are a few videos out there claiming that the decline in use of Bamboo in construction/'woodworking' in Japan was not only about availability of other materials like steel and later plastic.

There was/were some species of bamboo used by craftsman that bloomed and then failed to reproduce due to weather changes. You've been working with a species of bamboo for five generations and it's just completely gone in under a year.

[wccrawford]

It could be that they all bloom when they receive a certain signal from another plant of the same species, and that they will set off that signal after storing up for 130 years after the last bloom. So even new plants will receive the signal and bloom, but the trigger takes 130 years to re-arm.

[tabs_masterrace]

That sounds most plausible. After they bloom and all die, the first generation of new plants to grow will then start the 130 year clock again (by counting days or seasons) and be the first to release the signal again.

[jacobush]

I wonder if they could adapt to a longer or shorter year cycle. Expose seeds to conditions simulating say 20 year cycles or "summer" "spring" "fall" and "winter", only slightly compressed so they are passing by over 15 calendar years. Perhaps you will have a batch of bamboo flowering 5 years earlier than their kin in the wild?

[bluejellybean]

As another user mentioned, oscillating loops can achieve these phenomenon and they're extremely abundant in biology. The circadian rhythm is an excellent example of this behavior.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4758938/

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4073891/

[avip]

It's interesting the article says: ... even if there are no exogenous cues present, periodical patterns are still shown (1) indicating that these rhythms result from an internal time-keeping system. ... For humans, the most prominent circadian rhythm is the 24 h rhythm in the sleep-wake cycle.

I thought it's a well-studied fact that humans settle on a 30 hours sleep-wake cycle in constant light conditions?

[Obi_Juan_Kenobi]

No, it's somewhat longer, but much less dramatic at around 25 hours: https://journals.sagepub.com/doi/pdf/10.1177/074873040301800...

However, your confusion is understandable.

Nathaniel Kleitman spent a month in a cave in 1938 studying sleep/wake cycles, and found that he could maintain a 28 hour cycle. He did this deliberately, however, and this does not reflect the circadian rhythm. Rather, this wake/sleep cycle depends on C (the circadian rhythm) and S, homeostatic effects that reflect the previous period of wakefullness. It's also entirely possible to sleep at any point in the circadian rhythm (as anyone who has napped will know), so the circadian rhythm can simply decouple in extreme wake/sleep cycles (e.g. 20h or 28h).

http://www.chronobiology.ch/wp-content/uploads/publications/...

Also, even with the circadian rhythm not being preciesly 24 hours, it's still 24 hours with entertainment. That's the standard physiological condition; it really is a 24-hour cycle. Free-running is like removing a component of the clock, seeing that it doesn't keep 24-hour time, and calling it broken. That's not the case; entrainment is part of the process and how the body keeps coordinated with its environment.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2717723/

[Obi_Juan_Kenobi]

Plants depend crucially on timekeeping.

The Circadian Clock is essential for coordinating metabolism, growth, and reproduction, vernalization, etc. Most plants can be considered either short-day or long-day flowering, where highly-sensitive response to the delta in day-length is tracked to coordinate flowering. Nearly all plants anticipate events like sun-rise and sun-set with precision to coordinate (expensive!) photosynthetic expression, open/close stomata, alter xylem and phloem, etc.

Applying this to longer time-scales should not be terribly surprising for such sophisticated time-keepers.

Here's some information about in-vitro induction of flowering, induced with the sorts of chemicals you might expect (e.g. cytokinin promoting, auxin repressing):

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5603696/

As for the particular regulatory network that accomplishes this, it's very difficult to study an event that occurs so seldom. Even annual breeding cycles can make detailed genetic investigations take decades.

What we can infer from homology is that there's likely some kind of feedback and balance of hormones that 'count' the time. There is nothing "in the DNA" that tracks time, but the genes that DNA encodes can provide this clock function.

[dessant]

What does "same stock" mean in this case?

[foxhop]

Same stock typically means same root stock, which is how people propagate and bamboo naturally clones itself.

[cmrdporcupine]

Same clone.

[ComodoHacker]

Maybe they're not sensing absolute time, but sensing bloom events from other plants? Some mechanism akin to quantum entanglement perhaps?

[taneq]

Telomeres?

[hammock]

Doesn't have to be counting up. Counting down would be much easier.

[blahedo]

Counting up and counting down are the same thing, if 0 and 1 are arbitrarily assigned.

[hammock]

Help me understand. Here is what I am thinking:

If I have a cell with 5 "beans" (hypothetical counting organelle) in it. And the cell will die if it does not have at least one bean. These beans stack on top of each other like Legos, and "float" inside the cell so that the top bean is at the surface of the cell, exposed to the weather. Every winter the exposed bean dies, so that each year there is one less bean - and the next highest bean is now "floating" at the top. After 5 years there will be no beans left and the cell will die.

Now try to do that by counting up. How does it work?

[blahedo]

Ooh, I thought your post was a response to the binary-counting one but it's a sibling to yours—my comment was referencing that. In a binary-based arithmetic system of fixed number of bits, counting up from 000 to 111 is isomorphic with counting from 111 down to 000 if you flip all the bits.