水杨酸对牡丹叶片耐冷性的影响

摘要

In order to explore the physiological mechanism of salicylic acid (SA)improving ability against chilling in-jury 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 H2 O2 ,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 H2 O2 ,O-2 · and MDA,and membrane permeability of leaves of P .suffruti-cosa .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 re-duced chilling injury of leaves of P .suffruticosa .The longer the time of lower temperature treatment was,the stron-ger 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 un-der 4 ℃ for 12 h whether to 2 mmol L-1 SA use or not was the same.It was concluded that whether SA can ob-viously 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.%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·、H 2 O 2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.