沙芦内含物PAAC对干旱胁迫下玉米幼苗叶片光合及蛋白氧化损伤的保护作用

Effects of PAAC specifically contained in dune reed on maize seedling leaf photosynthesis and protein oxidation injury under drought stress

采用沙培试验,培养期间用沙丘芦苇特有的多氨基芳香族化合物PAAC水溶液对培养的两种不同基因型玉米幼苗叶片进行喷施处理,研究幼苗叶片在正常供水和干旱胁迫下的相对含水量、光合作用、叶绿素荧光等参数的变化趋势。确定这些生理指标在评价作物抗旱性方面的作用,并与甜菜碱溶液喷施处理的作物参比,研究该内含物对植物蛋白氧化损伤的影响。结果表明:PAAC溶液能够明显地降低干旱下植物叶片蛋白质中羰基含量的上升,即该内含物能够有效地减弱干旱胁迫下植物蛋白氧化损伤程度,RWC相对较高,说明PAAC一定程度上降低水分的散失。当植物受到中度干旱胁迫时,PAAC显著地减缓玉米叶片光合速率的下降,同时Fv/Fm、qP、ETR等叶绿素荧光参数数值也明显高于同期的对照,表明PAAC具有保护类囊体膜上PSⅡ的光合学活性的作用,一定程度上增强了植物的抗旱能力。

This paper studied the effects of the special polyamine aromatic compound（PAAC） on relative water content,main photosynthetic parameters,chlorophyll fluorescence parameters and protein oxidation injury of two different genotypes maize in seedling stage under well-watered and drought stress,via sand culture experiment.During the culture stage,maize leaves were sprayed with PAAC solution.Ascertain the function of these physiology indexes on evaluating drought-resistance of crop at seedling stage.Comparison was also made with the betaine treatment to study the effects of the inclusion on protein oxidation injury.The results show that spraying PAAC solution on leaves can significantly reduce the increasing of carbonyl content of plant leaves protein under drought stress.It suggest that the inclution can be effectively reduced the level of protein oxidation indury in plants under drought stress,and simultaneous measure the leaf RWC,found that the relative water content of PAAC-treated seedings are higher than others,which shows PAAC reduce water loss.When the plants are under moderate drought stress,the PAAC significantly slows down the photosynthetic efficiency reduction.Furthermore,the values of Fv/Fm,qP and ETR are also significantly higher than the control in the same period.It suggests that the PAAC can protect PSⅡ photochemical activity,maintain physiological function of plants and enhance the drought-resistant capacity of crops.