Impact of Pretilachlor on Wild and Mutant strains of Nostoc spongiaeforme

Abstract

In present research, impact of pretilachlor herbicide on two cyanobacterial strains: wild Nostoc spongiaeforme and mutant herbicide resistant Ns (MHR)⁵ was investigated. We elucidated physiological, biochemical responses of these cyanobacteria to pretilachlor and assessed potential for herbicide resistance. Results revealed that pretilachlor adversely effected growth, photosynthetic pigments and metabolic processes in both strains. Ns (MHR)⁵ showed greater resistance and resilience to pretilachlor. Pretilachlor significantly decreased photosynthetic pigments in both strains but Ns (MHR)⁵ exhibited lower reduction. Herbicide particularly affected photosynthetic processes with PS-II, photosynthetic chain activity, respiration and nitrogen assimilation processes more severely in N. spongiaeforme. Nitrate uptake was negatively impacted in N. spongiaeforme but not in Ns (MHR)⁵. LD₅₀ of pretilachlor to Ns (MHR)⁵ was observed to show higher tolerance. This research highlighted the potential for herbicide resistance in Ns (MHR)⁵. These findings shed valuable insights on broader implications of herbicide usage on aquatic ecosystems and for the evolution of resistance mechanisms in cyanobacterial populations.