外源水杨酸对梨叶片感染轮纹病菌后抗氧化酶活性及Ca^(2+)浓度的影响

Effect of Exogenous Salicylic Acid on Antioxidant Enzymes and Ca^(2+) Density in Pear Leaves Infected by Physalosproa piricola Nose

为了解水杨酸(Salicylic acid,SA)缓解轮纹病菌伤害植物的机理,用0.3 mmol L-1的SA预先处理梨叶片,3 d后接种轮纹病菌(Physalospora Piricola Nose),接种4 d后开始测定各种指标,随后每隔3 d测定1次,共5次.结果表明,经0.3 mmol L-1 SA处理后,梨叶片的超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)、抗坏血酸过氧化物酶(APX)、愈创木酚过氧化物酶(GPX)和谷胱甘肽还原酶(GR)的活性分别比对照组(CK1)提高了30.65%、25.36%、28.55%、21.11%、35.67%和26.45%.电镜观察表明,感染轮纹病菌的梨叶片,Ca2+较多分布在细胞膜内侧、细胞质及一些细胞器(叶绿体)上.经SA处理后感染轮纹病菌的梨病叶,Ca2+较多分布在细胞壁外侧及细胞间隙中,与正常梨叶片Ca2+的分布情况相似.表明较低浓度的SA可缓解轮纹病菌对梨叶片的伤害作用.

alicylic acid,a plant induced-resistance activator,is able to alleviate the injury of pathogen to plant.In this study,0.3 mmol L-1 salicylic acid（SA） was applied on the leaves of pear,after 3 d Physalosproa piricola Nose was inoculated,and 4 d after inoculation all indexes were measured.The measurement was made every 3 days for 5 times.The results showed that compared with CK1,the 0.3 mmol L-1 SA could increase the activities of SOD,POD,CAT,APX,GPX and GR proline in leaves by 30.65%,25.36%,28.55%,21.11%,35.67% and 26.45%,respectively.The observation with TEM showed that in the pear leaves infected by P.piricola,Ca2＋ was distributed on the inside of cell film,and on cytoplasm and some cell organs（such as chloroplast）.The SA treatment indicated that inside the vascular bundle,secretion of germina could be seen,Ca2＋ was mostly dotted on the outside of cell wall and between cells,which was similar to that in normal pear leaves,indicating that lower concentration of SA could reduce the damage of pear leaves by P.piricola.