Figure 1.

Prediction of the relationships among cysteine proteases, cystatins, NCR proteins, transcription factors and other genes in the regulation of nodule senescence. The dotted lines and/or question marks indicate that the relationship between the two proteins is uncertain. The double arrows indicate that the direct regulatory relationship between the two proteins is proved. The single arrows indicate that the relationship between the two proteins exists. The red ellipses indicate that the genes positively regulate nodule senescence. The green ellipses indicate that the genes negatively regulate nodule senescence. The ellipsis indicates that many genes have not yet been identified [10,21,23,25,31,40,41,42,44,46,47,48,49,50,51,54,55,56,57,58,59,60,61,62,63,64,65,66,67,68,69,70,71,72,73].