Abstract: Weextracted floret chloroplast proteins from the genetic male sterile line ms(S)-1376, the physiological male sterile line ms(A)-1376 induced by chemical hybridizing agent SQ-1, and their counterpart maintainer line (A)-1376 (normal fertility). These proteins were separated via 2-D electrophoresis with immobilized pH 4–7 gradients as the first dimension and SDS-PAGE as the second one. We established a set of technique available for intact chloroplast isolation and 2-DE of proteins in wheat floret and compared the effect of intact chloroplast purification using two methods. Based on the 2-DE technique, we explored the difference of the floret chloroplast proteins among the three materials tested in their early uninucleate anther stage. The result showed that we obtained high purity of intact chloroplast using discontinuous sucrose density gradient centrifugation with three-step gradient densities of 30%, 45%, and 60%. Proteins were extracted from chloroplast by TCA-acetone and analyzed by PDQuest software, we got as much as 239 protein spots within pH 4–7 and with molecular weight of 14.4–66.2 kD on each 2-DE gel. We analyzed six differential expressed proteins by matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) mass spectrometry (MS) and bioinformatical database, and found they were acyl-CoA dehydrogenase domain protein, calmodulin-binding protein phosphatase, multiple catalytic peptidase, heat-shock protein 60, light receptor protein 2 and a protein of unknown function. These proteins are involved in series of physiological reactions such as metabolism of energy substances, chloroplast defendance, chloroplasts signal transduction and plant growth, the differential expression of those proteins among the three materials tested is likely related to the male sterility in wheat.

Key words: Wheat, Genetic and physiological male sterilities, Intact chloroplast proteins, Differential expression, 2-dimensional electrophoresis, MALDI-TOF-MS