What would the biology of magic plants that get their energy through pure darkness look like?

Question

In a world just like our own, one day, everything turned dark. Literally, as the planet was consumed by near-total darkness, the clouds turning black and allow little to no natural sunlight through them.

However, through means no one knows how, but most assume is just magic, the same event that covered the world in darkness also had an effect on the plants. Almost every plant in the world was changed on a biological level so that instead of needing light to grow, they could instead use darkness as energy they need to survive, with only a few rare exceptions.

Assuming that the only change the magic in question did was make it so that plants of the world could get energy through darkness, what exactly would the biology of said plants look like if a scientist tried to study them?

Answer 1

Since darkness is not energy, but rather it is a lack of light energy, you would need to have your magical darkness absorb the incoming light and convert it into some other form of energy that your plants could use for photosynthesis. This energy type would need to be invisible to the human eye to get the darkness effect you want.

The biology of the leaf would change based upon what you chose the energy source to be. Plants are green because the chlorophyll absorbs the red and blue portions of sunlight while reflecting the green. Your plant's pigment would change accordingly. If they didn't require visible light at all they might turn white since they would reflect anything that wasn't your new energy source, or they could darken, absorbing all energy to compensate for their lack of energy production from sunlight.

You also need to think about the temperature issue. Without the sun's light, the planet would enter an ice age similar to a nuclear or impact winter. This would also change your plant's biology, as they would need to be heartier to survive in the frigid cold. Of course, maybe your converted energy source allows the heat from the sun to penetrate, just not the visible light. You could also solve this by having your energy source generate its own heat instead of letting the sun's pass through, which might allow creatures with specialized eyesight the ability to use it to see.

Answer 2

IMPORTANT NOTE - I am assuming in my response that by "light" you meant "light" and not "visible light". If you meant "visible light", heat is a form of light that we can't see. So, just have the darkness convert the photons to heat to grow the plants. Otherwise, if you actually meant "light", see below.

Well, if everything turned dark, it can't just be "destroying" the photons, that goes against physics. It has to be converting it to something else. You could use any energy, in my example I'll use heat.

To begin, I'll explain photosynthesis a bit. The chloroplast traps light energy and converts it to nicotinamide adenine dinucleotide phosphate (NADPH) and adenosine triphosphate (ATP). Those chemicals then go on to complete the process, but this is really all we need.

We can actually keep this process if we make the plant generate its own light to then use in that chemical process, which would make the plants glow. Essentially, the plants need to contain a molecule called luciferin, which is in bioluminescent animals and automatically produces light when in contact with oxygen. A catalyst such as luciferase could help speed up the process, but wouldn't be necessary.

Answer 3

"Literally, as the planet was consumed by near-total darkness, the clouds turning black"

This could be the effect of a frequency-shifting field. A spherical layer all around the planet has been turned into a nonlinear optical medium (in very limited volumes this can be done by magnetic fields, or it can happen in solid lattices, but in this case, well, magic - or sufficiently advanced technology), and it performs second-harmonic tuning on all photons comprised in the visible octave of 380 to 740 nanometers, shifting it into the 190 to 370 range, which means ultraviolet rays of A, B and C subtypes.

At the same time, plants have been reengineered genetically so that their clorophyll A and B molecules, already efficient enough in the blue and near ultraviolet range, are now packed differently and much more reactive in the full ultraviolet band. At the same time, their structure has changed so as not to be negatively affected by UV-A and UV-B, which is what would have happened before.

The viral vector that engineered the change was diffused over a period of several months, but its active phase was designed to trigger in the presence of significant quantities of UV-B rays. So, as soon as the frequency shifter field was activated, within a few hours all green plants "fell ill" and turned a sickly white, thereafter thriving on invisible light.

(The problem here is that staying in the open will now get you badly sunburnt).

A more convoluted transformation could perhaps convert visible light into microwaves, and have plants develop organic "rectennas" to capture their energy. Getting in the open will now just heat you up, just as if you were exposed to visible sunlight, except this would happen on a lesser level and on the whole body. Skin cancer would go down, but cataracts would go waaay up.

Answer 4

Who would have thought, that the universe started to expand so fast, that the space between earth and the sun was expanding faster than light.

The earth was in eternal darkness, since the light of no star was reaching it. Our only hope are the plants, who managed to feed on dark energy. The physics behind the plants are still unclear, but scientists all arount the world are working on resolving this and ultimatly stopping the heat death of the universe.

Since the physics is very unclear, you could argue with multiverses, unknown particles, anit-dark-matter(???)

This answer is fairly crazy.