模拟酸雨对棉花子叶呼吸作用的影响——兼讨论植物在逆境胁迫下的两种胁变模式

Effect of Simulated Acid Rain on the Respiration in Cotton Cotyledons——Discussion Simultaneously on the Two Types of Response Variation to Stress for Plant

以棉花子叶为材料研究了模拟酸雨对呼吸作用的影响。发现:棉花子叶呼吸强度与酸雨 pH 值之间呈一不规则单峰曲线关系,适度的胁迫能刺激子叶呼吸强度应激上升,过度的胁迫则抑制乃至终止呼吸作用;子叶呼吸强度与胁程之间在强酸雨(pH2.5～0.5)、中等强度酸雨(pH3.5～3.0)和低强度酸雨(pH5.0～4.0)胁迫下分别表现为负相关关系、单峰曲线关系和正相关关系;子叶呼吸强度应激上升的峰值与胁程之间呈正相关关系。呼吸强度应激上升的范围随胁程延长而缩小并移向高 pH 值,导致呼吸终止的 pH 值也是随胁程延长而移向高 pH 值,这共同说明:酸雨胁强与胁程对子叶呼吸作用的抑制具有协同加强的效应。本文还提出了植物在逆境胁迫中的两种胁变模式——生理性有序防御和机械性无序崩溃,并作了较仔细的讨论。

Effect was studied of simulated acird rain on the respiration in cotton cotyledlons. It was observed that for an irregular curve relationship with a single peak between respiratory strength(R)in cotton cotyledons and pH values of acid rain.R in cotton cotyledons could be risen by the moderate stress,but the inhibition or even stop for R under excessive stress of acid rain.The negative,curve with a single peak,and positive correlation were found between R and stress duration under stress of pH2.5～0.5,3.5 ～3.0.and 5.0～4.0 of acid rain,respectively.There was a positive correlation between peak value of R and stress duration.The range of pH values resulting in the stimulative increase of R narrowed with stress duration and muved to the higher pH values,so did the pH values resulting in the stop of respiration.These results indicated together a positive interaction from stress strength and duration of acid rain existed in respiratory inhibition.It was put forward and discussed deeply also for the two types of response variation to stress in plant——orderly physiological defence and disorderly machnical collapse at length.