There is no direct anagram, but POTRNUS forms the phrase "run stop", and the letters can spell smaller words such as stupor, unstop, and sprout.
Those letters spell natural.
The letters in "these letters" can spell the phrase "ether settles." The letters can spell shorter words such as trestles, sheerest, shelters, and treeless.
Those letters will spell dollar.
The letters spell 'broccoli'.
Those letters spell delicate.
Those letters spell psycho.
Those letters will spell carnivore.
Those letters will spell artichoke.
The letters can spell the anagram "annotation."
Those letters will spell turnip.
Those letters will spell democratic.
The letters spell weary.