Growth Properties and Ion Distribution in Different Tissues of Bread Wheat Genotypes (Triticum aestivum L.) Differing in Salt Tolerance

Journal of Agronomy and Crop Science (Impact Factor: 2.62). 02/2011; 197(1):21-30. DOI: 10.1111/j.1439-037X.2010.00437.x

Four bread wheat genotypes differing in salt tolerance were selected to evaluate ion distribution and growth responses with increasing salinity. Salinity was applied when the leaf 4 was fully expanded. Sodium (Na+), potassium (K+) concentrations and K+/Na+ ratio in different tissues including root, leaf-3 blade, flag leaf sheath and flag leaf blade at three salinity levels (0, 100 and 200 mm NaCl), and also the effects of salinity on growth rate, shoot biomass and grain yield were evaluated. Salt-tolerant genotypes (Karchia-65 and Roshan) showed higher growth rate, grain yield and shoot biomass than salt-sensitive ones (Qods and Shiraz). Growth rate was reduced severely in the first period (1–10 days) after salt commencements. It seems after 20 days, the major effect of salinity on shoot biomass and grain yield was due to the osmotic effect of salt, not due to Na+-specific effects within the plant. Grain yield loss in salt-tolerant genotypes was due to the decline in grain size, but the grain yield loss in salt-sensitive ones was due to decline in grain number. Salt-tolerant genotypes sequestered higher amounts of Na+ concentration in root and flag leaf sheath and maintained lower Na+ concentration with higher K+/Na+ ratios in flag leaf blade. This ion partitioning may be contributing to the improved salt tolerance of genotypes.

  • [Show abstract] [Hide abstract]
    ABSTRACT: Two wheat (Triticum aestivum L.) cultivars, Sids 1 and Giza 168, were grown under non-saline or saline conditions (4.7 and 9.4 dS m−1) with and without arbuscular mycorrhizal fungi (AMF) inoculation. Salt stress considerably decreased root colonization, plant productivity and N, P, K+, Fe, Zn and Cu concentrations, while it increased Na+ level, particularly in Giza 168. Mycorrhizal colonization significantly enhanced plant productivity and N, P, K+, Fe, Zn and Cu acquisition, while it diminished Na+ uptake, especially in Sids 1. Salinity increased putrescine level in Giza 168, however, values of spermidine and spermine increased in Sids 1 and decreased in Giza 168. Mycorrhization changed the polyamine balance under saline conditions, an increase in putrescine level associated with low contents of spermidine and spermine in Giza 168 was observed, while Sids 1 showed a decrease in putrescine and high increase in spermidine and spermine. Moreover, mycorrhizal inoculation significantly reduced the activities of diamine oxidase and polyamine oxidase in salt-stressed wheat plants. Modulation of nutrient acquisition and polyamine pool can be one of the mechanisms used by AMF to improve wheat adaptation to saline soils. This is the first report dealing with mycorrhization effect on diamine oxidase and polyamine oxidase activities under salt stress.
    Acta Physiologiae Plantarum 35(8). · 1.31 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Maintenance of a high K+/Na+ concentration ratio in plants by regulation of the expression of specific ion channels plays an important role in salt resistance. In this work, two melon cultivars differing in salt tolerance were used to evaluate melon inward rectifying K+ channel (MIRK) transcription, K+ and Na+ distribution, as well as stomata aperture under various salt treatments (0, 100 and 200 mM NaCl) for exploring the mechanism of salinity tolerance in melon. The salt-tolerant cultivar, cv. Bingxuecui (BXC), showed a smaller reduction in biomass due to salt treatments than the salt-sensitive cultivar, cv. Yulu (YL). Although the level of total Na+ in the whole plant was the same in both melon cultivars after salinity treatments, a lower Na+ level with higher K+/Na+ ratio was observed in the leaves of the BXC cultivar, which is likely to promote salt tolerance in melon. Salinity also resulted in down-regulation of MIRK transcription and stomata closure in the leaves of both varieties; however, compared to the YL cultivar, a lesser extent of MIRK transcription and stomata aperture reduction were observed in the BXC cultivar, both of which remained steadier at most sampling times. The high correlation observed between stomata aperture closure and MIRK transcription level suggests that the regulation of the MIRK channel in melon may be involved in modulation of the stomata apertures, subsequently balancing transpiration and CO2 exchange, which may ultimately contribute to a higher tolerance to salinity.
    Acta Physiologiae Plantarum · 1.31 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Two wheat (Triticum aestivum L.) cultivars, Sids 1 and Giza 168, were grown under non-saline or saline conditions (4.7 and 9.4 dS m−1) and were sprayed with 0.00, 0.05 and 0.10 mg l−1 24-epibrassinolide (EBL). Salt stress markedly decreased plant productivity and N, P, and K uptake, particularly in Giza 168. A follow-up treatment with 0.1 mg l−1 EBL detoxified the stress generated by salinity and considerably improved the above parameters, especially in Sids 1. Organic solutes (soluble sugars, free amino acids, proline and glycinebetaine), antioxidative enzymes (superoxide dismutase, peroxidase, catalase and glutathione reductase), antioxidant molecules (glutathione and ascorbate) and Ca and Mg levels were increased under saline condition, and these increases proved to be more significant in salt-stressed plants sprayed with EBL, particularly at 0.1 mg l−1 EBL with Sids 1. Sodium concentration, lipid peroxidation, hydrogen peroxide content and electrolyte leakage were increased under salt stress and significantly decreased when 0.1 mg l−1 EBL was sprayed. Clearly, EBL alleviates salt-induced inhibition of productivity by altering the physiological and biochemical properties of the plant.
    Acta Physiologiae Plantarum 35(3). · 1.31 Impact Factor


Available from
May 20, 2014