水杨酸对牡丹叶片耐冷性的影响

Effects of salicylic acid on cold resistence of Paeonia suffruticosa leaves

关键词:  牡丹叶片  抗寒性  水杨酸

Key words:  Paeonia suffruticosa leaves  cold resistance  salicylic acid

摘要:

为了探索低温胁迫下,水杨酸(salicylic acid,SA)提高牡丹叶片耐冷性的生理机制,以8年生牡丹品种‘胡红'20 d叶龄的叶片为试材,将其浸入0、0.5、1.0、1.5、2.0 mmol·L^-1的SA水溶液,置于4 ℃光照培养箱进行暗培养,经0、4、8、12 h的低温处理后取样测定其活性氧水平和保护酶活性,MDA、可溶性糖和可溶性蛋白含量及细胞膜透性。结果表明:施用低于2.0 mmol·L^-1的SA可减轻低温对牡丹叶片的伤害程度,降低O^-₂·、H₂O₂和MDA含量以及细胞膜透性,但能使可溶性糖、可溶性蛋白含量升高,POD、SOD和CAT活性增加。其中1.0 mmol·L^-1 的SA能显著降低叶片组织中O^-₂·和MDA的含量,明显降低低温引起的叶片水渍化程度,随着低温处理时间的增加,这种效果更加明显。施用2.0 mmol·L^-1的SA并不能明显减轻低温引起的叶片水渍化程度,当低温处理12 h后,叶片受到的低温伤害程度和没有施用SA时没有明显区别。总之,SA是否能明显提高牡丹叶片的耐冷性与其浓度有关,1.0 mmol·L^-1 的SA最能提高牡丹叶片的抗寒性,过低和过高浓度的SA则不能明显增加叶片的抗寒性。该研究成果能快速应用于牡丹的提早生产,并为增强其它作物的抗寒性提供理论参考。

Abstract:

In order to explore the physiological mechanism of salicylic acid(SA)improving ability against chilling injury of plant leaves,20 d old leaves of Paeonia suffruticosa cultivar ‘huhong' were treated by 0,0.5,1.0,1.5 and 2.0 mmol·L^-1 SA under 4 ℃ darkness incubator,and then effects of SA on the contents of H₂O₂,O^-₂·,soluble sugar,soluble protein and malonaldegyde(MDA)content,the activities of guaiacol-dependent peroxidase(POD),superoxide dismutase(SOD)and catalase(CAT),and membrane permeability in leaves of P. suffruticosa were investigated in 0,4,8,12 h later. The results showed that low concentration of SA(<2.0 mmol·L^-1)could reduce chilling injury of leaves of P. suffruticosa,the content of H₂O₂,O^-₂· and MDA,and membrane permeability of leaves of P. suffruticosa. However,it could increase the contents of soluble sugar and soluble protein,and activities of POD,SOD and CAT of leaves of P. suffruticosa. Especially,1.0 mmol·L^-1 SA could decrease contents of O^-₂· and MDA,and reduced chilling injury of leaves of P. suffruticosa. The longer the time of lower temperature treatment was,the stronger the protection of SA to leaves of P. suffruticosa was 2 mmol L^-1 SA did not significantly reduce the low temperature inducing leaf water salinization degree. The degree of chilling injury of leaves P. suffruticosa under 4 ℃ for 12 h whether to 2 mmol L^-1 SA use or not was the same. It was concluded that whether SA can obviously improve ability against chilling injury of leaves P. suffruticosa depended on SA concentration. 1.0 mmol·L^-1 SA reduced chilling injury of leaves of P. suffruticosa,while the lower or higher concentration SA could not obviously increase the cold resistance of leaves of P. suffruticosa. The results can be applied quickly in early spring production of P. suffruticosa,and provide the theoretical reference for ability against chilling injury of other crops.