The content is available as a PDF (133.3 KB).
. 2001 Apr;125(4):1554–1557. doi: 10.1104/pp.125.4.1554
Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.