Disruption could mean that could severely affect the photosynthetic process of the plants. If a certain mechanism is involved internally in the water cycle it would be evaporation. Hence, evaporation reduces the amount of water available on the soil. Furthermore, photosynthesis in autotrophs need water.
Pollution can also be a factor that can distract the process. Most especially, water pollution. Acid rain could be in particular. If the atmosphere is congested with toxic gases then when precipitation occurs the toxic chemicals are mixed in the raindrops that may result inability or dysfunctions in most plants to execute photosynthesis.