Some Relationships of Sterols to Plant Growth

Abstract
The embryos of mature pea seeds respond by increased growth when they are supplied in aseptic culture with certain sterols or steroidal materials. Of the 17 sterols and steroids tested, only one, estrone, possessed the activity of significantly increasing growth of pea embryos in culture. Other compounds and in particular, testosterone, were highly effective in inhibition of growth. Naturally occurring plant sterols such as ergosterol, stigmasterol, and sitosterol were without effect on pea embryo growth. The steroidal saponins both in crude preparation, and, in one instance, in chemically pure form,exert marked effects in increasing the growth of excised pea embryos.