Translocation of cholesterol from leaves to ripening fruits of Solanum khasianum

After foliar application of [4-¹⁴C]cholesterol to a Solanum khasianum shrub during a 6-week period, cholesterol was recovered not only from untreated leaves, but also from fruits at three different stages of maturity. In addition to free [4-¹⁴C]cholesterol, small amounts of [4-¹⁴C]cholesteryl esters but no [4-C¹⁴]cholesteryl glycosides were found in the fruits, treated, and untreated leaves. Thus, cholesteryl glycosides are probably not involved in the translocation of cholesterol. The implications of cholesterol translocation in the kinetics of solasodine Production are discussed.     

Fluence response relationship of carotenogenesis inNeurospora crassa

The fluence response of the blue light induced carotenoid synthesis inNeurospora is biphasic. Using fluence rates between 0.3 and 40 Wm^-2, increasing illumination times beyond 16 min (at 20°C) result in a second rise of the amount of carotenoids synthesized in the subsequent dark period. On altering the temperature, the transition point to the second phase of the response is shifted to shorter/longer illumination periods with increasing/decreasing temperature, respectively. The transition point can also be shifted by administering high fluence rates of near UV light: The start of the second phase is already triggered after an irradiation time of 2 min. The findings suggest that elements of the transduction sequence become depleted and senstivity recovers in a temperature-dependent process. The biphasic response and the effects of UV light are discussed in relation to the transduction mechanism and to the ecological significance.Presented in part at the meeting of the Deutsche Botanische Gesellschaft, September 1978, Marburg, Federal Republic of Germany