水分胁迫下苹果属植物叶片叶绿素降解的膜脂过氧化损伤作用

Membrane Lipid Peroxidation Damage Effect of Chlorophyll Degradation in Malus Seedlings Under Water Stress

苹果属植物幼苗在水分胁迫下,随着胁迫时间的延长,叶片叶绿素(Chl)降解加剧,活性氧(如O_2~、H_2O_2)、膜脂过氧化产物(如MDA)含量明显增加,细胞质膜相对透性(PMP)明显增大。其中,Chl、O_2~、H_2O_2、MDA、PMP的变化幅度表现为平邑甜茶大于新疆野苹果。经相关分析表明,Chl含量与O_2~、H_2O_2和MDA的含量,及PMP之间均呈显著负相关。V_E、抗坏血酸(ASA)和甘露醇预处理可延缓水分胁迫诱导的MDA含量的产生和减慢Chl降解;而Fe^(2+)、H_2O_2及Fenton反应则可刺激MDA含量的增加,加速Chl降解。

Active oxygen damage effect of chlorophyll degradation in Mains hupehensis pamp Reld. and Mains siev-ersii (Ledeb) Roem. seedlings were studied in water stress treatment. The results showed that the Chlorophyll (Chl)decreased under water stress, while the content of 02 and H202, MDA, PMP increased. The changing extents in Chi contents, the contents of O2 and H2O2, MDA, PMP in the drought tolerant variety M. sieversii were lower than the drought-resistant variety M. hupehensis. Chl degradation was accompanied by the increase of contents of 02 and H2 02 , MDA, PMP. A significant negative correlation between O2 , H2O2 , MDA, PMP contents and Chl content in M. hupehensis pamp Reld . and M. sieversii ( Ledeb) Roem. seedlings was found . Pretreatment with scavengers for active oxygen, such as ASA, a-tocopherol and mannitol retarded lipid peroxidation and reduced the oxidative injury of Chl, but Fe+ , H202 Fenton reaction promoted the formation of MDA, so the Fenton reaction accelerated the degradation of Chl.