Melavah Malkah Machshava
Mushrooms get a a bracha of 'shehakol nihyeh bidvaro'. The Gemara says that this is on account of the fact that they do not grow from the ground - they can grow on detached pieces of wood suspended in the air, this proves that they do not draw any sustenance, they therefore receive the 'baseline' bracha of 'shehakol' - the "catch-all" blessing. Truth is, the very fact that this benediction is so broad in its application (case in point: if you accidently make a 'shehakol' on a food that gets a 'mezonos' - you're yotzei your chiyyuv of making a bracha and can go right ahead and eat; nifty, huh?) reflects how profound in nature it (a blessing of 'shehakol') really is. In it, we express the infinite power of G-d; everything was created in His name.
Mushroom clouds are a reflection of something pretty powerful too - weaponry that can destroy wides swaths of countries in the blink of an eye. An aged Albert Einstein was quoted as having said something to the effect of: "If I would have known what my discoveries were to lead to...I would have become a watchmaker." After '45, Earth truly became a brave new world - arguably even darker than Aldus Huxley's vision.
Am Yisroel are all, individually and collectively, a 'chaylek Elokah mi'ma'hal', with great potential and kinetic capabilitiy; and although it might be relatively miniature and finite next to G-d's, it is nontheless comparable on some level, as it is He who vested us with our abilities. We can destroy worlds - but we can also use our ingenuity to create them and bring more G-dliness into this world. No character trait is good or bad in and of itself - it all depends on how it is channeled (my apologies for the requisite cliche').