Representative 2-DE gels of proteins from superior spikelets (SS) and inferior spikelets (IS) at three grain-filling stages.

<p>Three independent replicates for superior and inferior spikelets at each stage. EGS, MGS and LGS represent early, mid-, and late grain-filling stage, respectively, of endosperm development stages of SS and IS. Proteins prepared from SS and IS at the EGS, MGS and LGS were separated by 2-DE and stained by Coomassie Brilliant Blue. The differentially expressed protein spots between SS and IS at three stages were determined according to the method described in “<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0089140#s4" target="_blank">Materials and methods</a>”. MW (in kilodaltons) and pI of the proteins are shown at left and top, respectively.