Evaluation and improvement of spectrophotometric assays of TTC reduction: maize (Zea mays) embryo as an example

The triphenyl tetrazolium chloride (TTC) reduction assay was evaluated and improved with maize seed (Zea mays cv. Zhengdan958). The reduced TTC in embryo was extracted with three kinds of organic solvents: trichloroacetic acid (TCA)/acetone, ethanol, and acetone. The absorbance spectra of the three extracts were similar, with a maximum at 485 nm. The efficiency of TCA/acetone in extracting the reduced TTC was higher than that of acetone and ethanol. A negative correlation between TTC reduction and malondialdehyde content in embryo was demonstrated. The TCA/acetone extraction may be used as a routine protocol for TTC reduction assay of seed vigor in cereal (e.g. maize, rice, wheat and barley) seeds.