What happens when your plants “rest”, Part 2

Posted on November 13th, 2008 in biology by paphinessorchids

In this heretofore long-winded explanation of what happens when a plant “rests” for a season, we’ve reviewed some basic molecular biology.  Hopefully concepts like cells, molecules, DNA, and enzymes are more clear now.  If not, here’s a one sentence refresher:

Cells are biological units containing many kinds of molecules, DNA being a specific kind that tells the cell how to make enzymes, the molecules that do the work of a cell.

One thing that cells (and hence the organism they are a part of) do is adjust to changing conditions.  And in nature, nothing is more constant than the changing of seasons.   When winter approaches, certain enzymes of the cell monitor the shortening of days and the drop in temperature marking the approach of cooler weather.

Your typical enzyme molecule works with others of its same kind in a sort of gang on an assembly line, getting handed some tweaked molecule from the enzyme upstream,  which they then tweak themselves, and then passing it to the next guy down the line.  Sometimes, believe it or not, the enzymes tweak themselves and pass themselves down the assembly line!

Here’s a classic clip from I Love Lucy that I hope will illustrate the assembly line-like nature of biological processes:

Of course, if you’ve read my previous post, you’ll know that the assembly line analogy falls apart at some point, too, since what you really have are swarms/clouds of a specific enzyme type overlapping in 3-dimensional space other clouds of enzymes or reactants, all carrying on their highly specific work by randomly bumping into each other.  Yes, biology is very, very complex.  (And that’s why there’s still no cure for cancer despite the billions and billions of dollars spent on research.)

Anyways, back to the weather: how do enzymes “know” that seasons are changing?  After all, they don’t actually think, do they?  No, enzymes don’t think.  But they do react — and by react, I mean they are involved in chemical reactions.  And when, say, the temperature-monitoring enzymes experience a change in temperature, they fail to react in the way they usually do.  This makes all the difference in the world.

You can think of the cell as a vast array of different assembly lines/swarms manufacturing and reacting and moving all manner of molecules.  The temperature induced change in reaction rate gets transmitted down the line in what is like a giant Rube Goldberg contraption of mind-boggling complexity, until it reaches some central switch enzyme that controls the change-of-seasons genetic program.  In other words, the information about changing seasons is conveyed to this central switch enzyme, which then turns on all the enzymes that are needed for colder (or warmer) weather or when it’s time to put up a flower.  Just as a football team changes from offense to defense to special teams, so a plant has enzymes for spring, and enzymes for winter (or their relative equivalents in tropical slipper orchid country).

So back to the original question: what happens when you let your plants rest?

My answer is that the plant changes a genetic program.  It’s not because you might otherwise grow them to death.  Plants are designed to grow: that’s what they do.  But part of their growth cycle requires a switch to a different seasonal genetic program, which entails production of a bunch of different enzymes.  And the plant likely needs those enzymes to get made and do their thing for long-term health.

It’s kind of like those claims that your plants (or you) need trace elements such as selenium or molybdenum for health.  Some species of orchids need the change in seasons to cause the change in genetic program to cause the production of certain enzymes to do specific things so they’ll grow well and put up a flower for you.

Cells, enzymes, and the secret of DNA

Posted on August 13th, 2008 in biology by paphinessorchids

Most people have a good idea of what a cell is.  If you need more background, you can look here.

Here’s my working definition: A cell is a self-contained unit filled with everything it needs to make a copy of itself and do a specific job (assuming it’s part of another organism).  Inside the cell are armies of what I’ll call “molecular machines” that perform various chemical reactions.

Biology is a bit like quantum mechanics, in a way.  In quantum mechanics, if you keep peering deep enough, you’ll find that your “real world” intuition falls apart.  Stuff gets weird and counter-intuitive, and all kinds of oddly named particles get involved.

In biology, an analogous strange situation holds.  A useful word to keep in mind here is “swarm”.  Each bee in a swarm chasing you is the same as every other bee and they have one unifying goal — driving their stingers into your flesh.  A cell is full of multitudes of different swarms, each composed of identical molecules(*).  Every molecule in a collective swarm seeks to do its specific job (usually some specific chemical reaction).  The way things get done in this dance of swarms is by, believe it or not, bumper car-like collision.  Yep, what we observe as the exquisite and astonishing organization of living things derives from intersecting swarms of molecules colliding and reacting with other swarms(**) of molecules.  Absolutely amazing.

So what is an enzyme?  I’ll probably cover this in more detail on some other slow news day, but for now, suffice to say that enzymes are biological molecules — molecular machines –  designed to do a specific job.  Slap a methyl group on here, chop a hydroxy group off there, string some nucleotides, shred RNA, make ATP; all of these and myriad others performed by specific enzymes at specific times and places.

Enzymes pretty much do the work of the cell.  They are the worker bees, the factory workers on the floor, the office drones in the giant bureaucracy.  And the work of the cell is chemistry: chemical bonds synthesized and broken, on and on, propelled forward by the light of the sun.

So how does the cell “know” how to make enzymes?  Ahh, that’s the secret.  Well, it’s no secret, really, just that most folks get confused and intimidated by all the scientific terminology.  Here it is:

The DNA is the blueprint/the software/the plans for making enzymes.

That’s pretty much DNA’s main job, acting as the cell’s how-to manual for making the molecular workers that do the jobs inside a cell.  In orchids (and all plants), there are enzymes that make pigments, enzymes that fix DNA, enzymes that make cellulose, enzymes that destroy other enzymes, and enzymes that monitor the passing of the seasons.

And that brings us back to my original subject: what happens when you let a plant “rest”.  That’s the subject for my next post…

(*) OK, so what’s a molecule?  I think of a molecule as a grouping of atoms that has unique characteristics.

(**) The swarm analogy breaks down when you notice that enzyme molecules, unlike bees, don’t have brains.  They simply collide with other molecules.

What happens when your plants “rest”

Posted on August 12th, 2008 in biology by paphinessorchids

If you’ve been growing orchids for awhile, you’ve probably heard that some plants need to rest from growing during the winter (or other season).

I’ve always found this to be puzzling advice. Plants, like all biological life(*), are made up of cells. Think of a cell as an autonomous factory capable of taking care of nearly all of its own needs. As long as the raw materials are present, and it is not irreparably damaged, and it is getting the green light from whatever other cell might be bossing it around(**), it can continue to grow, repair itself, and pretty much do whatever it was designed to do.

One thing that most cells like to do is replicate themselves. You’ve probably heard of cell division (a.k.a. mitosis). Cell division is how living things grow. You start with one cell, which divides into two, then into four, and so on, and so on, and so on. Of course, at some point, some cells stop dividing according to the organism’s genetic program.

But why should a plant need a seasonal “rest”? What is it resting from?

Take us humans, on the one hand… We get up, eat, drink, sleep, reproduce (or try to). Our cells churn away making energy for all of those important activities we engage in day to day. They also divide so that we grow and repair ourselves. But our bodies do wear out, and in our cells, after each cell replication, a small chunk of DNA gets lopped off the end; past a certain point, the cell just dies. It’s the cell’s way of marking time. Hopefully we get to reproduce before that genetic clock shuts us down.

On the other hand, an orchid plant’s job is pretty much to grow, and look attractive (whether to bug pollinators or society judges, both justifiably regarded as pests in certain circles). If the plant has light, water, carbon, nutrients, etc., it ought to be able to simply keep growing, pretty much forever.

So why do orchid plants need a rest? Why is it that many growers claim that you need to keep your plants from growing themselves to death?

Well, this post looks like it’s going to be much longer than I thought, since we’ll need to talk about cells and enzymes first…  And that will be the subject of my next post.

(*) I’m not entering the debate on whether viruses, either biological or digital, are “alive”. That idea has been argued to death elsewhere (no pun intended).

(**) Yes, even cells have bosses ordering them around. Sometimes many different bosses.

How orchid seeds germinate

Posted on August 11th, 2008 in biology by paphinessorchids

It’s quite easy to pollinate a slipper orchid. Obtain pollen from the pollinating plant on the flat end of a toothpick, and then spread on the pollinating surface behind the staminode.

Wait 6 - 12+ months until you obtain seed, and then plant the seeds in an appropriate place. If you’re in the jungle, probably just letting the wind blow the seed away will work well enough, since that’s exactly what happens in nature. One seed pod can produce many thousands of seeds on a good cross — the vast majority never make it, but enough do that the species can continue.

Before the development around 1920 of chemically defined, sterile laboratory based media (looks like white or black Jello) for orchid seed germination, orchid cultivators would sprinkle paph seeds onto the media surface around the base of the parent plant. A few seeds would germinate, and result in plants that would put out leaves, grow roots, and follow the natural cycle of plant development. I haven’t tried this myself yet, but it’s definitely on my list of experiments.

Seeds of other plants ranging from trees to carrots to beans all carry their own energy storage in the form of starch. Orchid seeds, on the other hand, do not carry their own energy storage resulting in extremely fine, dust-like seeds easily carried by the wind. While the orchid plant is still just a seed without leaves to photosynthesize for energy, the seed gets its energy from fungi called mycorrhizae. While mycorrhizae is not a household term, these microbes are probably one of the most important fungi on the planet (more on these in a future post) since they are intimately involved in plant growth just about everywhere.

Mycorrhizae provide the initial sugar the orchid seeds need to germinate. The fungi enters into a symbiotic relationship with the orchid seed, producing sugar for the orchid seed to grow leaves and roots. In exchange, the developing orchid plant produces substances which the mycorrhizae uses for its own growth. Once the plant puts out leaves, it can begin photosynthesis and produce its own energy although the mycorrhizae continue to play an important role. And that’s something we’ll look at in a future post.

A peeve

Posted on April 29th, 2008 in market, collecting by paphinessorchids

What really bugs me are orchid ads I see claiming that such and such species are rare, when in fact, they are very, very common. For example, I recently saw a P. delenatii in bloom listed as a “rare” orchid. Nothing could be further from the truth. P. delenatii has got to be one of the most common orchids available commercially. Now, the alba form might have been considered rare a few years ago, but these days, it is at best “not often seen”. You can get fine examples of this form from many excellent growers (yes, we have a few at Paphiness Orchids).

There is a variant of P. delenatii that is indeed what I would call “rare”. The var. dunkel (meaning “dark” in German) has leaves with very heavy pigmentation, and the edges are dark purple, nearly black. But sooner or later, they will not be rare as breeders produce more and more of them.

In a future posting, I’ll go through what plants are truly rare.

Another split face mutant

Posted on April 21st, 2008 in mutants by paphinessorchids

Here’s another mutant from a recent white complex cross out of the Orchid Zone. The cross is called “Icy Icy Wind”, but this particular specimen has some interesting stuff going on, reminiscent of the ‘freak’ described here.

icy-icy-wind-split-face.jpg

This one is a little different from the ‘freak’, though. ‘Freak’ was clearly an example of sectoral chimerism, and you could see the different pigmentation effects on the leaves. It seems to me that ‘Freak’ was lucky to have the color split right down the middle. I don’t think the color will be split in the same spot on future bloomings, and the pigmentation patterns on the leaf would support that view.

This mutant P. Icy Icy Wind seems to me like it could actually be a germline mutation that might continue to breed this way. In ‘Freak’, it was presence of a layer of pigmented cells that happened to not be present on exactly half the flower (and the rest of the plant tissue for that growth). Here, nothing on the leaves or spike betrays any sectoral chimerism, and the difference has to do with the intensity of pigmentation rather than presence or absence.

Anyways, I’m just speculating here — we’ll know when it blooms again. (Thanks to SK at the Orchid Zone for the pic!)

A surprisingly unpopular species

Posted on March 31st, 2008 in species by paphinessorchids

If we were to think back to our days in elementary school (or pretty much any school), there was always the odd kid who no one hung around with. Usually, it was fairly obvious why that was the case.

Then there were some kids I recall who seemed like they ought to be in the popular crowd, but weren’t. They weren’t unattractive, or dirty, nor were there things personality-wise that caused them to be shunned. Maybe it was just that they were new, or had a tough time with the already-established cliques, or some chance event or accusation branded them as outcasts, although they were “normal” in every way. Some kids might have been cast as undesirables because they had different names, or had the wrong color lunch box, or maybe too much hair on their forearms.

I know a Paph species that seems like it ought to be in the popular crowd, but isn’t for some reason. As a species, it has a lot going for it:

  • a bold, brightly colored flower
  • distinctive flower form
  • easy to grow, can reach specimen size in reasonable time frame
  • not gargantuan, nor minuscule

What paph lover couldn’t at least be casual friends with this flower?

hirsutissiumum-close-up-500p.jpg

If you don’t know this species, please meet P. hirsutissimum. So why isn’t P. hirsutissimum more popular?

Is it the short stem?

The flower odor? (Well, here’s the news — there isn’t any).

The hair? Aha — maybe that’s it! Well, that’s what “hirsute” means: hairy! (Click hirsutissiumum-close-up.JPG to see the high-resolution picture where you can zoom in to see the fine detail)

But why let a little hair keep you from a love affair with this beautiful orchid? I mean, look closely at the popular kids in slipper orchid school — rothschildianum or sanderianum — and you’ll notice that they’re covered in warts!

I love mutants

Posted on March 31st, 2008 in mutants by paphinessorchids

Here’s another mutant, which (for obvious reasons) I’m calling ‘Triple Pouch’.

‘Triple Pouch’

Lovely!

I hope it continues to flower this way…

How to lose money on orchids

Posted on March 30th, 2008 in collecting by paphinessorchids

A great way to lose money on orchids is buying plants that are too small.

Take P. sanderianum: spectacular, highly desirable, envy-inducing. And slow-growing.

Every now and then I meet people who want to save money on a sanderianum by getting a small seedling. While seedlings a year or two out of flask may run $30 these days, what these folks don’t realize is the hidden cost in small seedlings. These hidden costs fall into several areas:

1) There is a huge risk in losing your seedling during the, oh, five to seven years it will take to get to maturity. Five to seven years is a long time to wait, and a lot can happen to a plant. Like infections. Pests. Power outages. Vacations where someone who was supposed to water your plants forgets to show up. While you may save some money upfront, you pay for it in the risk you absorb in attempting to grow a small seedling.

2) Your time, effort, and growing space have a cost. “Non-performing” plants (i.e., ones that take too long to bloom or don’t grow) should be candidates for replacement by ones that do “perform”: they bloom, or at least grow fast enough to keep you excited about it, or produce a division that can be traded or sold. Plants that sit, take up space, water, and care generally turn out to be a waste of time. (The same is true of stock market investments.)

3) Buyers don’t always have the opportunity to see ALL the sibs from a cross together to pick the strongest. In any flask, there will be more vigorous individuals and less vigorous individuals (which holds true in the classroom, gym class, standardized tests, etc.). So the seedling you get might be the best, or might be the runt.

A bigger plant will cost more, but it will be established. Its very size tells you something — it is a survivor. It was robust enough to handle whatever was thrown at it for the time it took to get to its size, whether that was bad weather, bad bacteria, or bad care, and it will be robust enough to have a chance at handling whatever you might throw at it!

The other benefit of larger size is its growth will accelerate once the plant reaches a certain size. The more leaf area, the more photosynthesis, the more growth, and hopefully, more energy to put into a bloom, one which you’ll be enjoying much sooner than with a seedling.

Believe me, this is not a ploy to get people to buy bigger plants from Paphiness Orchids. I’m very happy to sell seedlings of nearly any size, and do so reasonably well (usually to growers who are very patient, committed, and know from experience that some are not going to make it). And there’s nothing like growing a seedling to bloom, especially if it takes seven years.

P. rothschildianum ‘Charles E.’ FCC/AOS & ‘Borneo’ FCC/AOS

Posted on March 25th, 2008 in history, rothschildianum, species by paphinessorchids

The ‘Charles E.’ clone of P. rothschildianum is certainly a very influential plant in paph circles, and the ‘Borneo’ clone equally so. Both received FCCs and produced many progeny which themselves won numerous AOS awards. All well and good.

Every year, though, I get inquiries about these plants from excited collectors new to slipper orchids. New “pouch people” getting into roths are often dazzled by the awards given to ‘Charles E.’ and ‘Borneo’. What they don’t realize is how outdated those awards are, having been given thirty years ago. Now, I am not knocking the plants themselves — they are fine rothschildianums (and I’m proud to own both). But it’s sort of like flipping through old Playboy magazines from the 60’s — if you grew up in a era of silicone “perfection,” you’re astonished at how times and tastes have changed.

So where is a collector (of rothschildianums, not Playboys) to start?

I believe the current standard in roths is still ‘Rex’ FCC/AOS x ‘Mont Millais’ FCC/AOS produced by the Orchid Zone. One can easily and fairly argue, however, that the ‘Val’ FCC/AOS x ‘Mont Millais’ FCC/AOS cross from the Tokyo Orchid Nursery is the best. Well, as always, beauty is in the eye of the beholder, and when it comes to orchids, in the hands of the grower.

Progeny from both of these crosses has been the foundation of much of the current breeding in roths. The Orchid Zone has been continuing to push roth breeding by selecting the best of their ‘Rex’ x ‘MM’ plants, and crossing with progeny from ‘Nan Chou’ (a very dark roth) x ‘MM’ and other crosses. I have been fortunate to acquire a number of seedlings of this cutting edge breeding; if you are interested, please email me.

Many of the crosses coming from Asia these days actually bring both (Rex x MM) and (Val x MM) progeny together. (Actually, ‘Val’ FCC/AOS was one of the progeny of the ‘Charles E.’ x ‘Borneo’ cross.) In other cases, select plants have been outcrossed to plants originally wild-collected.

All of this genetic mixing and matching should produce some really spectacular stuff. So the future looks very exciting for roth nuts.

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