Which particles protons generate for positive charge? Photons are emitted from electrons according to Quantum Electrodynamics. So if we have a positive electric field, like having protons more than electrons in a system. So how does it able form a force against outside protons according to quantum level? And which carry particles are there to generate this force as there are no particles that protons generate ? Or can they generate?
 A: Photons interact with all charged particles, including protons... not just with electrons.
In QED the repulsive force between two protons is ascribed to “virtual photons”. These do not have all the same properties as the kind of real photons that we detect.
Many physicists argue that calling them “virtual particles” is a misnomer, so do not take them too seriously as particles. They are more of a mathematical shorthand for complicated field interactions. 
A: In the presence of both electrons and protons, the QED quantum loop corrections to the photon propagator would be dominated by the virtual electrons, rather than virtual protons.
The reason is that the vacuum polarization is (to the order of one quantum loop) 
$$
\Pi_{\mu\nu} \sim \int dq^4 Tr(\gamma_\mu\frac{1}{\not q -m}\gamma_\nu\frac{1}{\not q + \not p -m})
$$ 
where electron/proton mass appears in the denominator. 
Therefore the smaller mass (that is, the electron, instead of the proton which is $10^3$ times heavier), the larger contribution.
