两种外源化学物影响PEG胁迫对水稻根系的伤害  

Effects of two exogenous chemical substances on the osmotic stress-induced damages to rice roots

作　　者：冯汉青[1] 李芳[1] 管冬冬[1] 贾凌云[1] 

机构地区：[1]西北师范大学生命科学学院,兰州730070

出　　处：《广西植物》2013年第4期439-442,共4页Guihaia

基　　金：国家自然科学基金(30900105/31260059);教育部科学技术研究重点项目(211190);校级基金项目(NWNU-kjcxgc-03-77;NWNU-09-31&NWNU-LKQN-10-32)

摘　　要：研究过氧化氢内源消除剂和交替氧化酶专一性抑制剂影响渗透胁迫对水稻根系的伤害。结果表明:PEG6000胁迫抑制了水稻幼根的生长,降低了相对含水量、增加了H2O2含量,并导致细胞死亡。用5mmol·L-1二甲基硫脲(过氧化氢内源消除剂,dimethylthiourea,DMTU)预处理水稻幼根能明显降低PEG胁迫下水稻幼根过氧化氢的含量,缓解细胞死亡和相对含水量的降低,但对水稻根的生长影响较小。在PEG胁迫下,用1mmol·L-1水杨基氧肟酸(交替氧化酶专一性抑制剂,salicylhydroxamic acid,SHAM)预处理水稻幼根能显著降低水稻幼根的生长和相对含水量,并增加水稻幼根的过氧化氢含量和细胞的死亡程度。这说明DMTU能缓解PEG胁迫对水稻根系伤害,而SHAM加剧了PEG胁迫对水稻根系伤害。The effects of the scavenger of H2O2 and specific inhibitor of alternative oxidase on the osmotic stress-induced damages to rice roots were studied. The results showed that PEG 6000 inhibited the growth of rice roots,decreased the relative water content,inceased the H2O2 content,and caused cell death. Pretreatment with 5 mmol·L-1 dimethylthiourea（DMTU）,a scavenger of H2O2,significantly decreased the increment in the H2O2 content and partially alleviated the root cell death and the decrease of the relative water content induced by PEG 6000. However,DMTU had little effect on the growth of rice roots exposed to PEG stress. Under the PEG-induced stress,pretreatment with 1 mmol·L-1 salicylhydroxamic acid（SHAM）,a specific inhibitor of alternative oxidase,significantly decreased the growth of rice roots and relative water content,but increased the levels of H2O2 content and cell death. The results suggested that DMTU could alleviate the osmotic stress-induced damages to rice roots,whereas SHAM could intensify those damages.

关 键 词：过氧化氢 抗氰呼吸 水稻 渗透胁迫 

分 类 号：Q945.3[生物学—植物学]