Department of Molecular Biology and Genetics, Izmir Institute of Technology, Urla, Izmir, Turkey.
BMC Plant Biol. 2010 Apr 6;10:58. doi: 10.1186/1471-2229-10-58.
Excessive soil salinity is an important problem for agriculture, however, salt tolerance is a complex trait that is not easily bred into plants. Exposure of cultivated tomato to salt stress has been reported to result in increased antioxidant content and activity. Salt tolerance of the related wild species, Solanum pennellii, has also been associated with similar changes in antioxidants. In this work, S. lycopersicum M82, S. pennellii LA716 and a S. pennellii introgression line (IL) population were evaluated for growth and their levels of antioxidant activity (total water-soluble antioxidant activity), major antioxidant compounds (phenolic and flavonoid contents) and antioxidant enzyme activities (superoxide dismutase, catalase, ascorbate peroxidase and peroxidase) under both control and salt stress (150 mM NaCl) conditions. These data were then used to identify quantitative trait loci (QTL) responsible for controlling the antioxidant parameters under both stress and nonstress conditions.
Under control conditions, cultivated tomato had higher levels of all antioxidants (except superoxide dismutase) than S. pennellii. However, under salt stress, the wild species showed greater induction of all antioxidants except peroxidase. The ILs showed diverse responses to salinity and proved very useful for the identification of QTL. Thus, 125 loci for antioxidant content under control and salt conditions were detected. Eleven of the total antioxidant activity and phenolic content QTL matched loci identified in an independent study using the same population, thereby reinforcing the validity of the loci. In addition, the growth responses of the ILs were evaluated to identify lines with favorable growth and antioxidant profiles.
Plants have a complex antioxidant response when placed under salt stress. Some loci control antioxidant content under all conditions while others are responsible for antioxidant content only under saline or nonsaline conditions. The localization of QTL for these traits and the identification of lines with specific antioxidant and growth responses may be useful for breeding potentially salt tolerant tomato cultivars having higher antioxidant levels under nonstress and salt stress conditions.
土壤盐度过高是农业的一个重要问题，然而，耐盐性是一个复杂的性状，不容易被引入植物。据报道，栽培番茄暴露在盐胁迫下会导致抗氧化剂含量和活性增加。相关野生种 Solanum pennellii 的耐盐性也与抗氧化剂的类似变化有关。在这项工作中，对 S. lycopersicum M82、S. pennellii LA716 和一个 S. pennellii 导入系（IL）群体进行了评价，以评估它们在控制和盐胁迫（150 mM NaCl）条件下的生长和抗氧化活性（总水溶性抗氧化活性）、主要抗氧化化合物（酚类和类黄酮含量）和抗氧化酶活性（超氧化物歧化酶、过氧化氢酶、抗坏血酸过氧化物酶和过氧化物酶）水平。然后，利用这些数据来鉴定控制抗氧化参数的数量性状位点（QTL），这些参数在胁迫和非胁迫条件下都有。
在对照条件下，栽培番茄的所有抗氧化剂水平（超氧化物歧化酶除外）均高于 S. pennellii。然而，在盐胁迫下，野生种除过氧化物酶外，所有抗氧化剂的诱导作用都较大。ILs 对盐度表现出不同的反应，这对 QTL 的鉴定非常有用。因此，在对照和盐条件下共检测到 125 个抗氧化剂含量的 QTL。在使用相同群体的独立研究中，总共抗氧化活性和酚类含量 QTL 的 11 个匹配位点，从而增强了这些位点的有效性。此外，还评估了 ILs 的生长反应，以确定具有有利生长和抗氧化谱的品系。
当植物受到盐胁迫时，它们会产生复杂的抗氧化反应。一些位点控制所有条件下的抗氧化剂含量，而其他位点则仅在盐或非盐条件下控制抗氧化剂含量。这些性状的 QTL 定位和具有特定抗氧化和生长反应的品系的鉴定，可能有助于培育具有更高抗氧化水平的潜在耐盐番茄品种，这些品种在非胁迫和盐胁迫条件下都具有较高的抗氧化水平。
