Phytochrome Destruction in Dark ‐ and Light‐grown Amaranthus Caudatus Seedlings

Slow destruction of the far‐red‐absorbing form of phytochrome (Pfr), which has been observed in light‐grown oat and maize, occurs in light‐ and dark‐grown Amaranthus, Pharbitis, and Brassica seedlings as well. Destruction of Pfr in these seedlings shows two phases: if a high level of Pfr is produced in dark‐grown seedlings, the destruction is fast in the beginning and then slows after a low Pfr level has been reached. Slow Pfr destruction is predominant in light‐grown tissue.