As lame as fuck as it probably sounds, ever since seeing the movie
Reign of Fire, which takes place in a future where dragons are born from deep beneath the earth and burn all organic matter they can find on the earth, and inhaling the ash from it to survive. There are nothing but small factions of humans having to grow food to exist and try to keep it secret from the dragons who are starving and looking for organic matter to burn, I have been extremely interested in humanity's often taken-for-granted reliance on plant matter to exist. Here are some interesting articles I have come across while researching it:
Oldest viable seed - Wikipedia, the free encyclopedia
Svalbard Global Seed Vault - Wikipedia, the free encyclopedia