I vaguely recall having read, some years ago, also via hacker news, an account of the institute during the Nazi occupation. I think several employees had locked themselves in to safeguard the seeds, maybe also feeding on them

Could you be thinking of the Russian Institute of Plant Industry, in Leningrad?

https://www.rbth.com/blogs/2014/05/12/the_men_who_starved_to...

Yes, it was this! Thank you!