[mikeyouse]

For anyone wanting to learn more - the holy grail of Ag engineering would be to increase the efficiency of rubisco, which is the rate-limiting enzyme in photosynthesis - so understandably there’s a ton of research at doing just that.

https://en.m.wikipedia.org/wiki/RuBisCO

[JumpCrisscross]

Strongly recommend for one of the light-dependent reactions from before that enzyme: https://youtu.be/WhCczIqADuI

[murderfs]

A somewhat less (but still!) ambitious project is to retrofit C4 photosynthesis into rice. It's something like 50% more efficient, and has evolved independently dozens of times, so it's probably a lot more feasible.

[rendaw]

Why do we need more efficient photosynthesis in plants? Is it for indoor cultivation?

[mikeyouse]

If you had a widely applicable improvement, you’d be able to grow fruit trees in Canada or have two harvests in one season for food crops, or grow much denser species of wood, much more quickly for construction lumber. It would be massively world changing — but it is a 4 billion year old enzyme so is pretty entrenched..

[rendaw]

Oh interesting! Is photosynthesis the main thing limiting growth speed?

I would have expected there to be multiple processes with similar or aligned timings, or some built in limiting mechanism or something... it's not like giving humans higher calorie food makes them become adults faster.

[mikeyouse]

Improving rubsico would be more along the lines of improving your metabolism so that you can process 4,000 calories per day with the loose analog of supplying more CO2 being the ‘higher calorie food’. It’s the single largest bottleneck in photosynthetic efficiency. TBH, it would likely take several more breakthroughs for plants to make use of an improved rubisco but it’s still a massive target for ag research.

[melagonster]

Plants get more energy, so they generate more food.