Pharmacological modification of cysteine content and its reduction potential at low temperature. The Cys and CySS concentrations of Ch (A) and Tsp (B) and the reduction potential of both genotypes (C) were determined in the crowns of the wheat seedlings. The various compounds were applied to 12-day-old seedlings at 20/17°C for 3 days and subsequently at 5°C for 4 days. The numbers above the columns show the percentage of CySS compared to the total cysteine content. Values indicated by asterisks are significantly different from the corresponding control of each genotype, treated with no chemicals, at the P ≤ 0.05% level.