01626naa a2200157 a 450000100080000000500110000800800410001910000210006024501220008126000090020352011480021265000140136065000100137465000100138477300740139418365672012-09-05       1985    bl ---       0--  u    #d1 aWILKINSON, R. E.  aInhibition of conversion of geranylgeranyl-chlorophyll to phytol-chlorophyll by S-ethyl Dipropylthiocarbonate (EPTC).  c1985  aThe influence of EPTC (S-ethyl dipropylthiocarbamate) on the hydrogenation of geranylgeranylchlorophyll (GG-Chl) to phytol-Chl was studied during the greening (6-, 12-, 18-, 24-, and 48-hr incandescent light exposure) of etiolated wheat [Triticum aestivum (L.) cv ?Stacy?] and sorghum [Sorghum bicolor (L.) Moench cv ?G 522DR?] seedlings grown in nutrient solution containing 14C-labeled sodium acetate. Chloroplast pigment synthesis occurred and small quantities of GG-Chl were found in both Chl?a and Chl?b. When wheat seedlings were greened for 48 hr in an EPTC concentration series (1 nM to 100 ?M), geranylgeraniol (GG) content increased from 11% (control) to 60% (100 ?M EPTC) of the isoprenoid alcohol esterified to chlorophyllide a, but Chl-b contained ?1% GG-Chl at all concentrations of EPTC. Sorghum seedlings greened for 48 hr in the same EPTC concentration series contained about 3% GG (control) while 100 and 40% GG esterified to chlorophyllide a and chlorophyllide b, respectively, after 48 hr exposure to 100 ?M EPTC. Thus, EPTC prevented hydrogenation of GG-Chl to phytol-Chl on the Chl molecule more in sorghum than in wheat.  aClorofila  aSorgo  aTrigo  tPesticide Biochemistry and Physiologygv. 23, n. 2, p. 289-293, 1985.