Figure 2. The accumulation profile of the four major protease and two major protease inhibitor classes in wheat grains during grain development.

(A) The relative protease activities of four major protease families in wheat grain during grain development. Relative protease activities were summarized from previously reported enzyme assays [65] and are broadly consistent with recent quantitative proteome data [14]. (B) The fold change in protein abundance, total mRNA abundance (transcripts per million) and protein synthesis and degradation rates (in % change per day) of the four major protease families and the two protease inhibitor families during wheat grain development. The fold change in protein abundance and protein turnover rate data were originally reported by Cao et al. in 2022 [14], while the transcript data were originally reported by Pfeifer et al. in 2014 [67]. The averaged fold change in protein and the total mRNA abundance are presented for each family of proteins or transcripts. The median protein synthesis and degradation rates of each protein family during early- and middle grain filling stages from 7 to 17 DPA are also presented.