Display substrate, display panel, and display apparatus

A display substrate, comprising:

• a base substrate, comprising a bending region;
• a plurality of sub-pixels, located on the base substrate;
• and
• a pixel defining layer, having a plurality of first openings in the bending region, wherein orthographic projections of the sub-pixels in the bending region are located in orthographic projections of the first openings, a taper angle of the first openings is greater than a preset angle, and the taper angle of the first openings is in positive correlation with a curvature of the bending region, such that emergent light of the sub-pixels in the bending region is not blocked by the pixel defining layer;
• wherein in the bending region, a side surface of the pixel defining layer comprises:
• a first part, and a transition part and a second part, the transition part and the second part are arranged alternately to form a sawtooth structure at a boundary of a side of the first part close to the base substrate, wherein
• in a direction perpendicular to the base substrate, a thickness of the second part is greater than a thickness of the transition part and smaller than a thickness of the first part.