DOES NITROGEN FERTILIZATION ENHANCE DROUGHT TOLERANCE IN SUNFLOWER? A REVIEW

Water stress is one of the major limitations to the agricultural productivity around the globe, particularly in warm, arid and semi-arid regions of the world. Sunflower (Helianthus annuus L.), being a crop with medium water requirements, has the ability to tolerate a short period of drought. However, water stress in the soil as well as inside the plant influences various physiological and biochemical processes. This may inhibit plant growth, decrease developmental activities of the cells and tissues and cause a variety of morphological, physiological and biochemical modifications. Nitrogen (N) is one of the most important mineral nutrients because of its numerous effects on plant growth and yield. A number of fundamental processes such as water and nutrient uptake, protein metabolism, photosynthesis, carbon partitioning, and enzyme and plant hormonal activities are regulated by N. These responses result in profound changes in growth rate, net photosynthate production, plant development, and yield. It is well documented that nutrient uptake of plants is inhibited in dry soils and with expected nutrient deficiencies the normal functioning of the plants is affected. Different strategies are being practiced in the world to cope with the problem of nutrient deficiency under water stress. Nitrogen application either through soil or through foliar feeding is an important strategy to alleviate the adverse effect of drought. Supplemental application of N as foliar fertilization to soil-applied fertilization is important in situation where nutrient supply through soil is limited. Some of the relevant work available about the effect of water stress and nutrient availability in sunflower is reviewed in this paper.     

Interactive effects of salinity and iron deficiency on different rice genotypes

Salinity adversely affects plant growth, photosynthesis, and availability of nutrients including iron. Rice (Oryza sativa L.) is susceptible to soil salinity and highly prone to iron (Fe) deficiency due to lower release of Fe‐chelating compounds under saline conditions. In order to investigate the effects of salinity and low iron supply on growth, photosynthesis, and ionic composition of five rice genotypes (KS‐282, Basmati Pak, Shaheen Basmati, KSK‐434 and 99417), a solution culture experiment was conducted with four treatments (control, 50 mM NaCl, Fe‐deficient, and 50 mM NaCl + Fe‐deficient). Salinity and Fe deficiency reduced shoot and root growth, photosynthetic and transpiration rates, chlorophyll concentration, and stomatal conductance. The reduction in all these parameters was more in the interactive treatment of salinity and low Fe supply. Moreover, a significant increase in shoot and root Na⁺ with corresponding decrease in K⁺ and Fe concentrations was also observed in the combined salinity and Fe‐deficiency treatment. Among the tested genotypes, Basmati Pak was the most sensitive genotype both under salt stress and Fe deficiency. The genotype KS‐282 performed better than other genotypes under salinity stress alone, whereas Shaheen Basmati was the best genotype under Fe deficiency in terms of all the studied parameters.     

Mineral Uptake of Mycorrhizal Wheat (Triticum aestivum L.) under Salinity Stress

The hypothesis was that arbuscular mycorrhizal (AM) fungi are able to alleviate salt stress on plant growth by enhancing and adjusting mineral uptake. The objectives were to determine (1) the effects of soil salinity on mineral uptake by different wheat genotypes and (2) the effectiveness of different mycorrhizal treatments on the mineral uptake of different wheat (Triticum aestivum L.) genotypes under salinity. Wheat seeds of Chamran and Line 9 genotypes were inoculated with different species of AM fungi including Glomus mosseae, G. intraradices, and G. etunicatum and their mixture at planting using 100 g inoculum. Pots were treated with the salinity levels of 4, 8, and 12 dS/m before stemming. Different arbuscular mycorrhizal treatments, especially the mixture treatment, increased wheat mineral uptake for both genotypes. Although Line 9 genotype resulted in greater nutrient uptake under salinity stress, Chamran was more effective on adjusting sodium (Na⁺) and chloride (Cl^?) uptake under salt stress.     

Arbuscular mycorrhizal fungi for salinity stress: Anti-stress role and mechanisms

Salinity stress is considered one of the most harmful environmental plant stresses, as it reduces irrigated land crop production by over 20%worldwide.Hence, it is imperative to develop salt-tolerant crops in addition to understanding various mechanisms enabling plant growth under saline stress conditions.Recently, a novel biological approach that aims to address salinity stress has gained momentum, which involves the use of arbuscular mycorrhizal (AM) fungi in plant-microbe interactions. It has ...     

Silicon-induced changes in growth,ionic composition,water relations,chlorophyll contents and membrane permeability in two salt-stressed wheat genotypes

We investigated the effect of exogenously applied silicon (Si) on the growth and physiological attributes of wheat grown under sodium chloride salinity stress in two independent experiments. In the first experiment, two wheat genotypes SARC-3 (salt tolerant) and Auqab 2000 (salt sensitive) were grown in nutrient solution containing 0 and 100 mM sodium chloride supplemented with 2 mM Si or not. Salinity stress substantially reduced shoot and root dry matter in both genotypes; nonetheless, reduction in shoot dry weight was (2.6-fold) lower in SARC-3 than in Auqab 2000 (5-fold). Application of Si increased shoot and root dry weight and plant water contents in both normal and saline conditions. Shoot Na⁺ and Na⁺:K⁺ ratio also decreased with Si application under stress conditions. In the second experiment, both genotypes were grown in normal nutrient solution with and without 2 mM Si. After 12 days, seedlings were transferred to 1-l plastic pots and 150 mM sodium chloride salinity stress was imposed for 10 days to all pots. Shoot growth, chlorophyll content and membrane permeability were improved by Si application. Improved growth of salt-stressed wheat by Si application was mainly attributed to improved plant water contents in shoots, chlorophyll content, decreased Na⁺ and increased K⁺ concentrations in shoots as well as maintained membrane permeability.     

Implications of Calcium Nutrition on the Response of Salvadora persica (Salvadoraceae) to Soil Salinity

Effects of Ca (Ca²⁺) level on the response of germination and seedling growth of Salvadora persica Linn. (Salvadoraceae) to sodium chloride (NaCl) salinity in soil were investigated. Salinity significantly retarded the seed germination and seedling growth, but the injurious effects of NaCl on seed germination were ameliorated and seedling growth was restored with Ca supply at the critical level to salinized soil. Calcium supply above the critical level further retarded the seed germination and seedling growth because of the increased soil salinity. Salt stress reduced nitrogen, phosphorus, potassium, and Ca content in plant tissues, but these nutrients were restored by addition of Ca at the critical level to saline soil. The opposite was true for sodium (Na⁺). The results are discussed in terms of the beneficial effects of Ca for plant growth under saline conditions.     

Nitrogen and NaCl salinity effects on the growth and nutrient acquisition of the grasses Aeluropus littoralis,Catapodium rigidum,and Brachypodium distachyum

Salinity and low nitrogen availability are important growth‐limiting factors for most plants. Our objective was to assess the influence of nitrogen (N) and salt levels on the growth and mineral nutrition of three forage grasses of varying salt resistance which are widely found in Tunisian salt lands, Aeluropus littoralis, Catapodium rigidum, and Brachypodium distachyum. Their response to salt and N interaction has not been studied and further investigations are necessary. Twenty day–old plantlets were hydroponically cultivated in Hewitt's nutrient solution. Half the plants were then exposed to 100 mM NaCl and the other half to no NaCl, and N was supplied at 0.5 or 5.0 mM N as NH₄NO₃. Plants were harvested after 60 d growth. Saline treatment (100 mM NaCl) decreased growth of B. distachyum (a relatively salt‐sensitive plant), but no significant effect was noted for A. littoralis (a relatively salt‐resistant plant) in both low– and high–N availability treatments. However, the effect of 100 mM NaCl on growth of C. rigidum (a moderately salt‐resistant plant) depended on N level. Increasing N availability and NaCl did not influence phosphate, sulfate, calcium, and magnesium concentrations in both A. littoralis and C. rigidum, but increased N supply reduced shoot sodium and chloride (Cl^–) accumulation. Potassium acquisition in A. littoralis and C. rigidum plants was severely depressed by increasing N availability under saline and nonsaline conditions, respectively. In these species, the increase of nitrate accumulation via N was attenuated by salinity. In contrast, total N content and allocation toward shoots were enhanced in these conditions, especially in A. littoralis, the most resistant species. It appears that increasing N availability at moderate salt levels has a beneficial effect on growth of species with high and moderate salt resistance, but not on species with low resistance to salinity.     

Accumulation and distribution of Zn and Mn in soybean seeds after nutrient seed priming and its contribution to plant growth under Zn- and Mn-deficient conditions

Nutrient seed priming is a strategy to increase the seed reserves of mineral nutrients as primary source for mineral nutrition during seedling development and early growth. The present study investigates the effects of zinc (Zn) and manganese (Mn) seed priming on growth and nutritional status of soybean under conditions of Zn and Mn limitation. Nutrient seed priming increased the natural seed reserves for Zn by, approximately, sixfold and by fivefold for Mn; however, 40–60% of the primed nutrients were adsorbed to the seed coat. Zinc seed priming was able to maintain plant growth for 5 weeks in the same way as Zn supply via the nutrient solution. It is concluded that nutrient seed priming offers perspectives to improve seed quality of soybean for early seedling development under limited nutrient supply or availability and needs further investigation on performance under various stress conditions.     

Effects of water and exogenous Si on element concentrations and ecological stoichiometry of plantain (Plantago lanceolata L.)

Silicon (Si) is widely distributed in nature and can promote plant growth under various biotic and abiotic stresses. Drought stress seriously affects plant growth and the concentration and ecological stoichiometry of nutrients. Integrated nutrient management effectively protects plants from stresses. However, the role of water and Si availability on element concentrations and stoichiometry in plantain (Plantago lanceolata L.) are unclear. Accordingly, this study observed changes in the concentration and stoichiometry of macro- and micro-elements in plantain leaves supplied with various levels of Si under variable water availabilities through a greenhouse experiment. Supplemental Si increased Si concentration of leaves under both well-watered and drought conditions. Without supplemental Si, drought conditions decreased concentrations of carbon (C), C: nitrogen (N), C: phosphorus (P), silicon (Si):N, Si:P and increased concentrations of N, P, N:P, Si:C, calcium (Ca²⁺), magnesium (Mg²⁺), iron (Fe), manganese (Mn), zinc (Zn), and copper (Cu). Increased Si under water stress increased concentrations of C, C:N, C:P, Si:C, Si:N, and Si:P, and decreased concentrations of Ca²⁺, sodium (Na⁺), and Mg²⁺. These results suggested that exogenous Si changed the concentrations and ecological stoichiometry of macro- and micro-elements.     

CONTRIBUTION OF PROLINE AND INORGANIC SOLUTES TO OSMOTIC ADJUSTMENT IN COTTON UNDER SALT STRESS

Physiological responses to salt stress were investigated in two cotton (Gossypium hirsutum L.) cultivars (Pora and Guazuncho) grown hydroponically under various concentrations of NaCl. Dry matter partitioning, plant water relations, mineral composition and proline content were studied. Proline and inorganic solutes were measured to determine their relative contribution to osmotic adjustment. Both leaf water potential (Ψ_w) and osmotic potential (Ψ_s)decreased in response to NaCl levels. Although Ψ_wand Ψ_s decreased during salt stress, pressure potential Ψ_p remained between 0.5 to 0.7 MPa in control and all NaCl treatments, even under 200 mol m^?3 NaCl. Increased NaCl levels resulted in a significant decrease in root, shoot and leaf growth biomass. Root / shoot ratio increased in response to salt stress. The responses of both cultivars to NaCl stress were similar. Increasing salinity levels increased plant Na⁺ and Cl^?. Potassium level remained stable in the leaves and decreased in the roots with increasing salinity. Salinity decreased Ca²⁺ and Mg²⁺ concentrations in leaves but did not affect the root levels of these nutrients. The K/Na selectivity ratio was much greater in the saline treated plants than in the control plants. Osmotic adjustment of roots and leaves was predominantly due to Na⁺ and Cl^? accumulation; the contribution of proline to the osmotic adjustment seemed to be less important in these cotton cultivars.     

转碱蓬SsNHX1基因烟草的耐盐抗旱性研究

烟草是重要的模式植物和经济作物,盐害和干旱两种环境因子对其生长发育、产量和品质都危害很大。为了提高烟草的耐盐抗旱性,本研究利用农杆菌介导的遗传转化法在烟草中过量表达了碱蓬液泡膜Na~+/H~+逆向转运基因SsNHX1,对转基因烟草的耐盐及抗旱性进行表型鉴定和各项生化指标的检测,以期得到耐盐抗旱表性良好的SsNHX1转基因烟草。表型分析发现,SsNHX1基因过表达株系L1和L5的抗盐能力比野生型显著提高,表现为盐胁迫条件下仍能保持旺盛的生长且根系的伸长未受抑制。SsNHX1过表达株系在叶片和根系中积累了更多的Na~+和K~+,同时Na~+含量增长速率较快,而K~+含量降低速率较缓,并可维持较高的叶片相对含水量和叶绿素含量,及较低的丙二醛含量和相对电导率。干旱胁迫发现,过表达株系受干旱胁迫程度更小,并在复水后迅速恢复正常生长。同时,过表达株系的丙二醛含量和相对电导率显著低于野生型,且维持了较高的叶片相对含水量及叶绿素含量。这些结果说明SsNHX1基因在烟草中过量表达后,降低了盐胁迫和干旱胁迫对烟草根系及细胞膜的损伤,并通过调节离子含量、降低细胞的渗透势,维持了叶片较高的相对含水量和叶绿素含量,最终提高了烟草的抗盐和抗旱性。     

Responses of barley to hypoxia and salinity during seed germination,nutrient uptake,and early plant growth in solution culture

The resistance of most plants to salt can be impaired by concurrent waterlogging. However, few studies have examined this interaction during germination and early seedling growth and its implications for nutrient uptake. The aim of the study was to examine the response of germination, early growth, and nutrient uptake to salt (NaCl) and hypoxia applied to barley (Hordeum vulgare L. cv. Stirling), in solution culture. Hypoxia, induced by covering seeds with water, lowered the germination from 94% to 28% but salinity and hypoxia together lowered it further to 13% at 120 mM NaCl. While the germination was 75% at 250 mM NaCl in aerated solution, it was completely inhibited at this NaCl concentration under hypoxia. Sodium ion (Na⁺) concentrations in germinated seedlings increased with increasing salinity under both aerated and hypoxic conditions during germination, while K⁺ and Mg⁺ concentrations were decreased with increasing salinity in 6 d old seedlings. After 20 d, control seedlings had the same dry weights of the roots and shoots with and without hypoxia but at 10 mM NaCl and higher, shoot and root dry weight was depressed with hypoxia. Sodium ion increased in roots and shoots with increased NaCl under both aerated and hypoxic conditions while K⁺ was depressed when salinity and hypoxia were applied together and Ca²⁺ was mostly decreased by NaCl. In general, hypoxia had greater effects on nutrient concentrations than NaCl by decreasing N, P, S, Mg, Mn, Zn, and Fe in shoots and by increasing B concentrations. The threshold salinity levels decreased markedly for germination, uptake of a range of nutrients, and for seedling growth of barley under hypoxic compared to well‐aerated conditions.     

Improved Nutrient Uptake Enhances Cotton Growth and Salinity Tolerance in Saline Media

Two experiments were conducted to determine if improved nutrient uptake increases salinity tolerance of cotton (Gossypium hirsutum L.). A transgenic cotton line (CMO3) with increased salt tolerance and its wild line (SM3) were grown in pots containing substrate (peat:vermiculite = 1:1, v/v) in the first experiment, while cotton (‘SCRC 28’) was cultured in hydroponics with a split-root system in the second experiment. Contents of essential nutrient elements and Na⁺ in plant tissues, leaf photosynthesis (Pn) and chlorophyll (Chl) concentration and plant biomass were determined after salinity [sodium chloride (NaCl)] treatment in both experiments. In the first experiment, salinity stress with 150 mM NaCl reduced plant biomass and photosynthesis (Pn) of both SM3 and CMO3 compared with their non-stressed controls, but the CMO3 suffered significantly lower reductions than SM3, suggesting an increased salinity tolerance of CMO3 relative to SM3. Total uptake and contents of main nutrient elements [nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), iron (Fe), manganese (Mn), copper (Cu), and zinc (Zn)] in CMO3 were higher than those in SM3. Also, less sodium (Na⁺) accumulation and lower extreme ratios of Na/N, Na/P, Na/K, Na/Ca, Na/Mg, Na/Fe, Na/Mn, Na/Cu, and Na/Zn were observed in CMO3 than in SM3. Increased salt tolerance in transgenic AhCMO cotton was probably attributed to its superior nutrient uptake compared with SM3. In the second experiment, the non-stressed root half fed with moderate level of nutrient solution and salt-stressed half fed with low level of nutrient solution (CMN/SLN) exhibited higher salinity tolerance than salt-stressed root half fed with moderate level of nutrient solution and non-stressed root half fed with low nutrient solution (CLN/SMN). Plants absorbed more nutrients but less Na⁺ under CMN/SLN than CLN/SMN. The overall results suggest that improved nutrient uptake played an important role in the enhanced salt tolerance of cotton.     

WHEAT GENOTYPES DIFFERED SIGNIFICANTLY IN THEIR RESPONSE TO SILICON NUTRITION UNDER SALINITY STRESS

We studied the growth and ionic composition of five wheat genotypes (Inqlab-91, Uqab 2002, SARC-1, SARC-3, and SARC-5) grown under salinity stress to applied silicon. Plants were grown with three levels of salinity [0, 60, and 120 mM sodium chloride (NaCl)] in the presence of 0, 2, and 4 mM Si in nutrient solution for 40 days. Salinity stress significantly decreased shoot and root biomass in plants with varying degrees. Genotype SARC-3 exhibited higher salt tolerance than other genotypes. Silicon (Si) application significantly (P < 0.05) increased plant biomass at both control as well as under saline conditions. Genotypes differed significantly for their response to applied Si in terms of biomass production. Silicon application significantly (P < 0.01) increased potassium (K⁺) concentration in shoots. Enhanced salinity tolerance in wheat by Si application was attributed to increased K⁺ uptake thereby increasing K⁺/sodium (Na⁺) ratio and lower Na⁺ translocation towards shoot.     

盐胁迫下柚实生苗生长、矿质营养及离子吸收特性研究

以坪山柚为材料,对盐胁迫下实生苗生长、矿质营养及离子吸收特性进行了研究。结果表明,沙培30d,80～200mmol/L盐胁迫,随盐浓度提高,坪山柚实生苗株高、叶面积、地上部干重和根部干重明显降低。溶液培养8d,坪山柚实生苗地上部及根Na+、Cl-含量随盐浓度的增加而增加,根及地上部K+、Ca2+、Mg2+以及P和Mn含量下降,Fe、Zn、Cu含量的变化因器官而异。其中,地上部Fe含量对盐胁迫敏感,可作为柚耐盐性鉴定指标。40mmol/L盐胁迫,坪山柚地上部K+/Na+、Ca2+/Na+、Mg2+/Na+值均显著下降,且Mg2+/Na+值+/Na+值>1;浓度≥160mmol/L盐胁迫,K+/Na+值+吸收、运转效率比Cl-高。     

NUTRIENT BIOAVAILABILITY IN SALT AFFECTED SOILS

Salt affected soils limit crop yields around the world. Knowledge of how nutrient availability is affected in plants growing on salt affected soils is important in adopting appropriate management practices to satisfy plants’ nutritional requirements and improve yields to meet food demands of increasing world populations. In the salt affected environment plants required to absorb essential nutrients from a dilute source in the presence of highly concentrated nonessential nutrients. Nutrient uptake and use efficiency in salt affected soils is low due to salt stress and negative interactions with cations and anions present in high concentrations. Hence, a higher amount of nutrients is necessary in salt affected soils compared to normal soils. Biological nitrogen fixation is also adversely affected in legumes grown on salt affected soils. Salts also reduce activity of many enzymes which supply energy for nutrient uptake. The important soils and plant management practices which can improve nutrient uptake and use efficiency in salt affected soils are use of soil amendments to reduce effect of salts, application of farmyard manures to create favorable plant growth environments, leaching salts from soil profile and planting salt tolerant crop species or genotypes within species. Addition of fertilizers, especially potassium may also help in reducing salinity effects and improving nutrient use efficiency.     

Growth response of the salt-sensitive and the salt-tolerant sugarcane genotypes to potassium nutrition under salt stress

Adequate regulation of mineral nutrients plays a fundamental role in sustaining crop productivity and quality under salt stress. We investigated the ameliorative role of potassium (K as K₂SO₄) in overcoming the detrimental effects of sodium chloride (NaCl) on sugarcane genotypes differing in salt tolerance. Four levels of NaCl (0, 100, 130 and 160 mM) were imposed in triplicate on plants grown in gravel by supplying 0 and 3 mM K. The results revealed that application of NaCl significantly (p ≤ 0.05) increased sodium (Na⁺) but decreased K⁺ concentrations in shoots and roots of both genotypes with a resultant decrease in K⁺/Na⁺ ratios. Physical growth parameters and juice quality were also markedly reduced with increasing NaCl concentrations compared with controls. However, addition of K alleviated the deleterious effects of NaCl and improved plant growth under salt stress. Cane yield and yield attributes of both genotypes were significantly (p ≤ 0.05) higher where K was added. Juice quality was also significantly (p ≤ 0.05) improved with the application of K at various NaCl levels. The results suggested that added K interfered with Na⁺, reduced its uptake and accumulation in plant tissues and consequently improved plant growth and juice quality in sugarcane.     

Enhancing of symbiotic efficiency and salinity tolerance of chickpea by phosphorus supply

This study aims to highlight the beneficial effect of the phosphorus on enhancing of growth plant, the efficiency of use rhizobial symbiosis and ionic partition in chickpea grown under salt stress. Exposure of plants to salt stress (0, 150 mM of NaCl) caused ionic imbalance, which resulted in increased Na⁺ and P and reduced K⁺ contents in the leaves and root. Indeed, stressed plants showed decrease of plant growth and phosphorus use efficiency. The efficiency use of rhizobial symbiosis was also affected by salinity. However, addition of two different level of phosphorus (37 and 55 mM) to saline soil increased significantly availability of P in plant organs. Specially, the (150 mM NaCl?×?37 mM P) mixture increased (33%) phosphorus use efficiency, induced better nodulation and increased plant biomass which results in the high efficiency in use of the rhizobial symbiosis. Our findings suggest that the combination of low level of P to saline soil presumably improved the tolerance of chickpea plant to salinity.

Abbreviations: phosphorus (P); phosphorus use efficiency (PUE); biological nitrogen fixation (BNF); plant dry weight (PDW); yeast extract mannitol (YEM); efficiency in use of the rhizobial symbiosis (EURS); shoot dry weight (SDW); symbiotic nitrogen fixation (SNF).     

Nitrogen nutrition and adaptation of glycophytes to saline environment: a review

Relations between nitrogen (N) nutrition and salinity tolerance in plants are multifaceted and varies significantly depending on many soil and plant factors. Saline environment might experience an N dilemma due to the opposing effects of salt ions on N uptake, translocation and metabolism within the plant body. Adequate regulation of N under saline conditions can be a promising approach to alleviate salinity’s effects on plants by ameliorating ion toxicity and nutrient imbalances through its impacts on the uptake and redistribution of salt ions within the plant. Certain N-containing compounds including proline, glycine betaine, proteins and polyamines help the plants to tolerate salinity through their involvement in improving water uptake and water use efficiency, membrane integrity, enzyme activation, hormonal balance, chlorophyll synthesis, stimulation of photosystems and CO₂ assimilation under salinity stress. Nitrogen, particularly NO₃^? represents a stress signal that triggers the activation of antioxidant enzymes to protect the plants against salinity-induced oxidative damage. Furthermore, the source/form of N application can affect not only N-interactions but also the behavior of other nutrients in stress environment. The present review deals with N-salinity relations in plants, particularly glycophytes, emphasizing on N-induced mechanisms which can improve plant adaptation to saline environment.     

Tomato and eggplant scions influence the effect of rootstock under Na2SO4 salinity

A short-term experiment was conducted to investigate whether the effect of rootstock on plant response to salinity depends on the solanaceous species used as scion. Tomato cv. ‘Ikram’ and eggplant cv. ‘Black Bell’ were grafted onto two tomato interspecific hybrids (‘Beaufort’ and ‘He-Man’). Plants were grown in an open soilless cultivation system and supplied with two nutrient solutions: non-saline control and a saline solution (adding 15 mM Na₂SO₄, 3.7 dS m^?1). Plant dry biomass production and partitioning were influenced by salinity, but its effect was depending on the rootstock/scion combination. ‘Beaufort’ eliminated the deleterious effect of salinity when tomato was used as scion, but reduced (?29.6%) the shoot biomass of eggplant. ‘He-Man’ had a different effect on scion growth under saline conditions: shoot biomass was less reduced in eggplant (?20.6%) than in tomato (?26.8%). Under salt stress, ‘Beaufort’ reduced the accumulation of Na⁺ in tomato leaves more than in eggplant, whereas no differences were observed between tomato and eggplant grafted onto ‘He-Man’. Stem Na⁺ accumulation followed a different pattern. The increase of Na⁺ in the stems was similar for tomato and eggplant grafted onto ‘Beaufort’, whereas stems of tomato accumulated more Na⁺ compared to eggplant grafted onto ‘He-Man’. The opposite response of the tested rootstocks to salt stress when the scion was either tomato or eggplant seems to be partially related to the capacity of the rootstock and scion to exclude Na⁺ from the shoot. However, the results of nutrient accumulation within plant tissues imply that other mechanisms in addition to ion competition are involved in the salt resistance of grafted plants.