Gunas are equivalent contributors. Though, they are subtle in expression and are generally exhibited by their properties or qualities.
Doshas explain the physical attributes and vulnerability to various probable diseases of an individual. A regime to avoid these diseases and lead a healthy and contented life is also mentioned in the ayurvedic texts. But this is the half aspect of a wider view.
This clearly depicts the interaction and dependence of doshas and gunas.
Doshas are made up of panchmahabhootas, the five basic elements of the nature: aakash (ether), vaayu (air), agni (fire), jal (water) and prithvi (earth). These panchmahabhootas further comprises of three gunas: sattva, rajas and tamas.