摘要
以抗旱甘蔗品种ROC22为材料,调查水分胁迫及胁迫加喷施脱落酸(ABA)对甘蔗内源ABA合成及相关生理生化作用的影响。结果表明,干旱及干旱加外施ABA的条件下,甘蔗内源ABA合成水平上升,但干旱加ABA处理增幅更显著,甘蔗叶内的脯氨酸(Pro)、H2O2、丙二醛(MDA)含量增加,而ABA处理能缓解MDA的积累,使其含量处于低水平,ABA处理能防止叶绿素降解并对干旱引起的最大光能转化效率(Fv/Fm)、PSII实际量子效率(ΦPSII)下降有明显的缓解作用。干旱条件下,H2O2的积累伴随着抗氧化作用的酶CAT、GPX、GR和APX的活性提高,而ABA处理能进一步提高这些相关酶的活性而逐渐降低H2O2的含量,表明干旱条件下,外施ABA能增强甘蔗的抗氧化防护系统,提高抗旱性。
Drought is a major limiting factor for sugarcane growth. Abscisic acid （ABA） regulates much important plant physiological and biochemical processes, and induces tolerance to different stresses including drought. Understanding the mechanism of tolerance to drought in sugarcane plant with foliage dressing of ABA under water stress would facilitate breeding and field management for improving drought resistance. Thus, an experiment was set up to investigate the interrelationship between drought induced ABA biosynthesis and antioxidative defense system, and to confer the farther role of foliar application of ABA in imparting drought tolerance to the sugarcane plant. The treatments were： T1 （drought）, T2 （drought ＋ foliar application of 15 μmol L–1 ABA） and C （control, normal irrigation） using a drought tolerant cultivar ROC22. The results showed that drought treatment （T1） enhanced the ABA concentration in leaf that was significantly higher in combined treatment （T2）, suggesting the ABA biosynthesis was triggered in leaf by the ABA application. Both T1 and T2 resulted in an increase in proline, H2O2 and MDA contents while the exogenous ABA alleviated the increase in MDA content. ABA application decreased the degradation of chlorophyll, and counteracted, at least in part, the decrease in maximal PSII efficiency （Fv/Fm） and quantum efficiency of PSII （ΦPSII）. Overproduction of H2O2 in T1 was followed by increasing activities of CAT, GPX, GR, and APX, which was further improved by the ABA treatment （T2）. A decrease in H2O2 level with increasing stress in T2 showed that ABA highly induced antioxidative defense system which was found to be vanished progressively in T1. The results clearly suggest that the tolerant cultivar showed an enhanced protective system against drought conditions, and the foliar application of ABA further improved its tolerance by triggering the over expression of antioxidative defense system.
出处
《作物学报》
CAS
CSCD
北大核心
2010年第5期863-870,共8页
Acta Agronomica Sinica
基金
广西农业科学院博士后研究专项(博后74602)
广西科技攻关项目(桂科攻0782004-3)
国家科技支撑计划项目(2007BAD30B03)
现代农业产业技术体系建设专项资金资助
关键词
ABA
甘蔗
抗旱性
H2O2
抗氧化酶
叶绿素荧光
ABA Sugarcane Drought tolerance Antioxidative enzyme H2O2 Chlorophyll fluorescence
