Search

Search Results

• 1. [Article] Sulfhydryl and disulfide changes in young wheat seedlings during vernalization

  A study of the SH and SS content levels during vernalization of wheat was made. In order to carry out the study, a rapid analytical technique was worked out which allowed fast sequential analyses of the ...

  Citation × Citation Citation Abstract Copy Title: Sulfhydryl and disulfide changes in young wheat seedlings during vernalization Author: Ellis, Robert William A study of the SH and SS content levels during vernalization of wheat was made. In order to carry out the study, a rapid analytical technique was worked out which allowed fast sequential analyses of the samples of wheat tissue. Two techniques were used: a) an amperometric titration method and b) a fluorescence quenching method. The amperometric titration method consisted of adding aliquots of samples of wheat tissue homogenate to the system and noting the decrease in current, due to a tie-up of Ag⁺ by the SH groups of the sample. The system consisted of a rotating platinum electrode connected to a mercury-mercuric oxide reference cell. The supporting electrolyte was a 0.14M solution of tris at pH 7.4. The fluorescence quenching method consisted of adding aliquots of sample to a solution of fluorescien mercuric acetate (FMA) in a 1N NaOH media. The SH and SS groups reacted with FMA in a one:one ratio. The reacted FMA was unable to fluoresce, thus making possible a quantitative assay for SH and SS groups in solution. Red Bobs, a spring wheat, and Elgin, a winter wheat, were grown in the dark at 3° C. and at 20° C. The SH and SS contents of the shoots were measured throughout a period of five weeks in the group grown at 3° C. and a period of 48 hours in the group grown at 20° C. The results of the analyses showed that the SH, SS, and SH+SS contents based on fresh weights were present in greater quantities in the tissues of Red Bobs grown at 20° than in the Elgin tissues grown at 20°. The high SH and SS concentrations present in the warm-grown Red Bobs tissues were due to a high concentration of protein extracted from that tissue. The SH, SS, and SH+SS contents per fresh weight were quite similar in the cold-grown tissues of both varieties during the growth period. These constituents present in the cold-grown tissues occurred in quantities that were less than those found in warm-grown Red Bobs tissues and greater than those present in the warm-grown Elgin tissues. Both varieties grown at both temperatures showed a similar decrease in SH and SS contents based on fresh weights as maturation progressed. The analyses indicated that SH, SS, and SH+SS contents based on protein levels were similar in Elgin and Red Bobs tissues grown at 20°. Both varieties grown at 3° contained greater concentrations of SH, SS, and SH+SS groups based on protein levels than those present in the tissues grown at 20°. The Elgin tissues at 3° underwent a fluctuation of these values as growth progressed, while the Red Bobs tissues at 3° maintained relatively constant levels of SH, SS, and SH+SS contents based on protein levels present during the growth period. It was concluded that the levels or patterns of SH and SS groups in young spring and winter wheat shoots were not correlated with the capacity of these plants to flower. Title: Sulfhydryl and disulfide changes in young wheat seedlings during vernalization Author: Ellis, Robert William A study of the SH and SS content levels during vernalization of wheat was made. In order to carry out the study, a rapid analytical technique was worked out which allowed fast sequential analyses of the samples of wheat tissue. Two techniques were used: a) an amperometric titration method and b) a fluorescence quenching method. The amperometric titration method consisted of adding aliquots of samples of wheat tissue homogenate to the system and noting the decrease in current, due to a tie-up of Ag⁺ by the SH groups of the sample. The system consisted of a rotating platinum electrode connected to a mercury-mercuric oxide reference cell. The supporting electrolyte was a 0.14M solution of tris at pH 7.4. The fluorescence quenching method consisted of adding aliquots of sample to a solution of fluorescien mercuric acetate (FMA) in a 1N NaOH media. The SH and SS groups reacted with FMA in a one:one ratio. The reacted FMA was unable to fluoresce, thus making possible a quantitative assay for SH and SS groups in solution. Red Bobs, a spring wheat, and Elgin, a winter wheat, were grown in the dark at 3° C. and at 20° C. The SH and SS contents of the shoots were measured throughout a period of five weeks in the group grown at 3° C. and a period of 48 hours in the group grown at 20° C. The results of the analyses showed that the SH, SS, and SH+SS contents based on fresh weights were present in greater quantities in the tissues of Red Bobs grown at 20° than in the Elgin tissues grown at 20°. The high SH and SS concentrations present in the warm-grown Red Bobs tissues were due to a high concentration of protein extracted from that tissue. The SH, SS, and SH+SS contents per fresh weight were quite similar in the cold-grown tissues of both varieties during the growth period. These constituents present in the cold-grown tissues occurred in quantities that were less than those found in warm-grown Red Bobs tissues and greater than those present in the warm-grown Elgin tissues. Both varieties grown at both temperatures showed a similar decrease in SH and SS contents based on fresh weights as maturation progressed. The analyses indicated that SH, SS, and SH+SS contents based on protein levels were similar in Elgin and Red Bobs tissues grown at 20°. Both varieties grown at 3° contained greater concentrations of SH, SS, and SH+SS groups based on protein levels than those present in the tissues grown at 20°. The Elgin tissues at 3° underwent a fluctuation of these values as growth progressed, while the Red Bobs tissues at 3° maintained relatively constant levels of SH, SS, and SH+SS contents based on protein levels present during the growth period. It was concluded that the levels or patterns of SH and SS groups in young spring and winter wheat shoots were not correlated with the capacity of these plants to flower. Close