Ultrastructural evidence of damage to leaf stromal protein four hours after treatment with paraquat

An ultrastructural investigation of paraquat-treated leaf tissueof Lolium perenne seedlings using negative staining techniquesalongside conventional ultrathin sectioning methods revealedextensive damage to the Rubisco molecules after only 4 h inlight. The early involvement of hydroxyl radicals in chloroplaststroma destruction is discussed. Key words: Lolium perenne, paraquat, chloroplasts, ultra structure, negative staining