Hernández Jose A, Aguilar Ana Belén, Portillo Bruno, López-Gómez Elvira, Beneyto Jorge Mataix, García-Legaz Manuel F
Department of Nutrition and Plant Physiology, Centro de Edafología y Biología Aplicada del Segura (CEBAS-CSIC), PO Box 164, E-30100 Espinardo-Murcia, Spain. Corresponding author; email:
Department of Agroquímica y Medio Ambiente (UMH), PO Box 43, E-03300 Orihuela (Alicante), Spain.
Funct Plant Biol. 2003 Jan;30(11):1127-1137. doi: 10.1071/FP03098.
Salt treatment (50 mM NaCl) reduced plant growth of loquat (Eribotria japonica Lindl.) (by up to 40%) but not that of anger (Cydonia oblonga Mill.). Salt stress induced a strong leaf Na accumulation in both species. However, the observed increase in leaf Cl level was higher in loquat (13-fold) than in anger plants (3.8-fold). Addition of Ca (25 mM) significantly reduced Na and Cl concentrations in both salt-treated species. In anger leaves, calcium addition to the nutrient media did not change the leaf calcium contents in salt-treated or untreated plants, this value being lower in salt-treated plants. However, in loquat plants, an increase in leaf Ca was observed after the calcium addition. Surprisingly, an increase in Ca concentration was also observed in salt-treated loquat plants. In general, anger plants had higher constitutive antioxidant enzyme levels in both control and salt-treated plants. Salt stress did not change antioxidant enzyme levels in loquat plants. A similar effect was observed in anger plants, but in this case a 2-fold induction of monodehydroascorbate reductase (MDHAR) activity was observed.In both species, salinity produced an oxidative stress, indicated by an increase in lipid peroxidation, this value being much higher in loquat (83%) than in anger (40%) plants. In salt-treated plants, Ca addition provided some protection to the membranes, because the increases observed in thiobarbituric-acid-reactive substances (TBARS) were not significant.In contrast, in control plants Ca treatments increased glutathione reductase (GR) and decreased catalase activity in anger, but increased MDHAR, dehydroascorbate reductase (DHAR), GR and superoxide dismutase (SOD) in loquat plants. In salt-treated plants, Ca additions decreased catalase (CAT) and ascorbate peroxidase (APX) for anger and raised DHAR, GR and SOD for loquat. However, the mechanism by which Ca regulates antioxidant enzymes remains to be determined.These results suggest that anger plants have a higher capacity to scavenge AOS, both under saline and non-saline conditions. Accordingly, and related to the smaller Cl increase observed, anger plants are more salt-tolerant, at least partly owing to the higher antioxidant enzyme levels observed.
盐处理（50 mM NaCl）使枇杷（Eribotria japonica Lindl.）的植株生长减少（最多达40%），但对榅桲（Cydonia oblonga Mill.）的植株生长没有影响。盐胁迫导致两个物种的叶片中钠大量积累。然而，观察到枇杷叶片中氯含量的增加幅度（13倍）高于榅桲植株（3.8倍）。添加钙（25 mM）显著降低了两个经盐处理物种中的钠和氯浓度。在榅桲叶片中，向营养培养基中添加钙并未改变盐处理或未处理植株的叶片钙含量，盐处理植株中的该值较低。然而，在枇杷植株中，添加钙后观察到叶片钙含量增加。令人惊讶的是，在经盐处理的枇杷植株中也观察到钙浓度增加。总体而言，无论是对照植株还是经盐处理的植株，榅桲植株的组成型抗氧化酶水平都较高。盐胁迫并未改变枇杷植株中的抗氧化酶水平。在榅桲植株中也观察到了类似的效应，但在这种情况下，观察到单脱氢抗坏血酸还原酶（MDHAR）活性有2倍的诱导。在两个物种中，盐度都产生了氧化应激，表现为脂质过氧化增加，枇杷植株中的该值（83%）远高于榅桲植株（40%）。在经盐处理的植株中，添加钙为膜提供了一定保护，因为观察到的硫代巴比妥酸反应性物质（TBARS）的增加并不显著。相比之下，在对照植株中，钙处理增加了榅桲中的谷胱甘肽还原酶（GR）并降低了过氧化氢酶活性，但增加了枇杷植株中的MDHAR、脱氢抗坏血酸还原酶（DHAR）、GR和超氧化物歧化酶（SOD）。在经盐处理的植株中，添加钙降低了榅桲中的过氧化氢酶（CAT）和抗坏血酸过氧化物酶（APX），并提高了枇杷植株中的DHAR、GR和SOD。然而，钙调节抗氧化酶的机制仍有待确定。这些结果表明，无论是在盐胁迫还是非盐胁迫条件下，榅桲植株清除活性氧的能力都更强。因此，与观察到的氯增加幅度较小相关，榅桲植株更耐盐，至少部分原因是观察到其抗氧化酶水平较高。
