Caspase-like enzymatic activity and the ascorbate-glutathione cycle participate in salt stress tolerance of maize conferred by exogenously applied nitric oxide
Caspase-like enzymatic activity and the ascorbate-glutathione cycle participate in salt stress tolerance of maize conferred by exogenously applied nitric oxide
复制标题
DOI：
10.4161/psb.18967
复制
发表时间：
2012-01-01
影响因子：
2.9
通讯作者：
Ludidi, Ndiko
中科院分区：
文献类型：
--
作者：
Keyster, Marshall;Klein, Ashwil;Ludidi, Ndiko
盐胁迫引起离子胁迫（主要来自高Na+和Cl-水平）和渗透胁迫（由于抑制根的水分吸收和植物组织的水分损失扩大），导致细胞死亡和生长抑制，并最终不利地降低作物生产力。以玉米（Zeamays L.）为试材，研究了玉米根系NO含量、地上部和根系生物量、根系H2 O2含量、根系脂质过氧化、根系细胞死亡、根系半胱天冬酶活性、根系抗氧化酶活性、根系抗坏血酸和谷胱甘肽含量/氧化还原态的变化。cv Silverking）在长期（21天）盐胁迫（150 mM NaCl）后，用或不用外源施加的由一氧化氮供体2，2 ′-（羟基亚硝基肼基）二乙烷产生的一氧化氮。除了降低地上部和根系的生物量，盐胁迫增加了一氧化氮和H2 O2含量在玉米根中，并导致在根中的脂质过氧化，半胱天冬酶样活性和细胞死亡的升高。在盐胁迫下，根中抗氧化酶活性发生变化，沿着抗坏血酸和谷胱甘肽含量/氧化还原状态发生变化。外源施加一氧化氮可逆转盐胁迫对根系的不利影响。这些结果表明，外源施加的一氧化氮赋予玉米盐胁迫耐受性，通过减少盐胁迫诱导的氧化应激和半胱天冬酶样活性的过程中，通过增强抗氧化酶活性限制活性氧的积累。
Salinity stress causes ionic stress (mainly from high Na+ and Cl- levels) and osmotic stress (as a result of inhibition of water uptake by roots and amplified water loss from plant tissue), resulting in cell death and inhibition of growth and ultimately adversely reducing crop productivity. In this report, changes in root nitric oxide content, shoot and root biomass, root H2O2 content, root lipid peroxidation, root cell death, root caspase-like enzymatic activity, root antioxidant enzymatic activity and root ascorbate and glutathione contents/redox states were investigated in maize (Zeamays L. cv Silverking) after long-term (21 d) salt stress (150 mMNaCl) with or without exogenously applied nitric oxide generated from the nitric oxide donor 2,2' (Hydroxynitrosohydrazano)bis-ethane. In addition to reduced shoot and root biomass, salt stress increased the nitric oxide and H2O2 contents in the maize roots and resulted in elevated lipid peroxidation, caspase-like activity and cell death in the roots. Altered antioxidant enzymatic activities, along with changes in ascorbate and glutathione contents/redox status were observed in the roots in response to salt stress. The detrimental effects of salt stress in the roots were reversed by exogenously applied nitric oxide. These results demonstrate that exogenously applied nitric oxide confers salt stress tolerance in maize by reducing salt stress-induced oxidative stress and caspase-like activity through a process that limits accumulation of reactive oxygen species via enhanced antioxidant enzymatic activity.