The characteristics of PEPCase activity and accumulation of oil,protein and major protein subunits during seed development of rape(Brassica napus)

The dynamic accumulation of moisture,oil,total protein,major storage protein(2S and 12S fractions) and their subunits,and variation of PEPCase activity during seed development of rape were investigated in this study with the variety of Qinyou No7.The correlations between PEPCase activity and these seed components were further studied.The results showed that during seed development,moisture content decreased from 81.61% to 23.22%.The content of oil,protein and soluble protein increased from 0.26% to 31.38%,1.1% to 21.36% and 0.63% to 12.21% respectively.The accumulation of 12S started earlier than that of 2S.The correlations between the activity of PEPCase and the protein content,and oil content were found during different stages of seed development;negative correlations were found between the activity of PEPCase and oil content/protein content ratio,as well as the content of 12S,α 2-3,α 4,β2,β3,and β4;No correlation was found between the activity of PEPCase and 2S fraction content and its subunits.