Microcitrus species are mainly rainforest trees, and not normally subject to fire, as a natural landscape cycle. Eremocitrus, maybe the NT humpty -doo lime,(gracilis), and maybe Mt White Lime (garrowayi) in Cape York are found in fire prone savannah, but not all plants in that region are triggered by fire.
Usually they have some mechanism like hard woody cones/pods that only open after fire, or germination inhibitors that are "turned off" by something in smoke.