In spite of available information demonstrating the assimilation of cyanide (CN) by β-cyanoalanine synthase (β-CAS) in plants, involvement of sulfurtransferase (ST) in CN assimilation in rice plants is still undefined. In this study, a microcosmic hydroponic system was used to investigate the involvement of β-cyanoalanine synthase (β-CAS) and sulfurtransferase (ST) in the CN assimilation in rice seedlings under the exposure of potassium cyanide (KCN) in presence or absence of 1-amino-cyclopropane-1-carboxylic acid (ACC). Our results indicated that the measurable thiocyanate (SCN) was detected in both rice roots and shoots under KCN exposure, and the abundances of ST-related transcripts were up-regulated sig... More
In spite of available information demonstrating the assimilation of cyanide (CN) by β-cyanoalanine synthase (β-CAS) in plants, involvement of sulfurtransferase (ST) in CN assimilation in rice plants is still undefined. In this study, a microcosmic hydroponic system was used to investigate the involvement of β-cyanoalanine synthase (β-CAS) and sulfurtransferase (ST) in the CN assimilation in rice seedlings under the exposure of potassium cyanide (KCN) in presence or absence of 1-amino-cyclopropane-1-carboxylic acid (ACC). Our results indicated that the measurable thiocyanate (SCN) was detected in both rice roots and shoots under KCN exposure, and the abundances of ST-related transcripts were up-regulated significantly (p < 0.05), suggesting that the ST pathway is involved in CN assimilation in the rice plants. The application of exogenous ACC significantly (p < 0.05) decreased the accumulation of CN and SCN in rice tissues after KCN exposures, and also up-regulated the expression of β-CAS and ST genes and their enzymatic activities, suggesting a positive interaction between aminocyclopropane-1-carboxylate oxidase (ACO), β-CAS and ST in rice plants during the CN assimilation. This is the first attempt to experimentally clarify the involvement of ST in CN assimilation in rice seedlings.
