Soil salinity is one of the major environmental stresses limiting agricultural productivity.

High concentrations of soluble salts can make it harder for roots to obtain water, expose plant cells to damaging concentrations of sodium and chloride ions, disrupt mineral nutrition and interfere with photosynthesis.

Trehalose has attracted substantial research interest as a potential way of helping plants manage these effects.

A 2026 systematic review and meta-analysis identified 15 separate studies investigating externally applied trehalose under salinity stress, making salinity the second-largest category in the agricultural trehalose literature after drought.[1]

A dedicated 2025 review of trehalose and plant salinity tolerance concluded that externally applied trehalose can influence several of the processes plants use to cope with salt, including osmotic regulation, antioxidant defence, photosynthesis, membrane protection and ion homeostasis.[2]

Research in crops including tomato, maize, rice and wheat increasingly supports this broader picture.[3–9]

Why is salinity harmful to crops?

Salinity affects plants in two closely related stages.

The first is osmotic stress.

When large quantities of dissolved salts accumulate around the roots, the plant finds it more difficult to extract water from the soil. A plant can therefore experience physiological water stress even when the soil itself appears moist.

The second problem is ion toxicity.

As sodium and chloride accumulate inside plant tissues, they can:

• interfere with potassium uptake
• disrupt enzyme activity
• damage membranes
• impair chloroplasts
• disturb nutrient balance
• reduce photosynthesis
• increase oxidative stress
• restrict root and shoot development.

Excess sodium is particularly problematic because plants require potassium for numerous physiological processes, while sodium can compete with it for transport and cellular binding sites.

The ability to maintain a favourable potassium-to-sodium balance is therefore an important component of plant salt tolerance.[2–4]

What does the overall research show?

The strongest cross-study evidence comes from the 2026 meta-analysis of externally applied trehalose under abiotic stress.[1]

Researchers screened 659 publications and included 52 eligible studies, of which:

15 investigated salinity stress.

Across the full evidence base, trehalose produced significant beneficial overall effects on many measures relevant to salt-stressed plants, including:

• plant water status
• chlorophyll
• photosystem efficiency
• gas exchange
• antioxidant activity
• osmolyte accumulation
• shoot and root growth
• plant height
• leaf area
• grain yield.[1]

Trehalose treatment was also associated with lower concentrations of several markers of cellular damage, including hydrogen peroxide, lipid peroxidation and membrane permeability.[1]

The studies differed considerably in crop species, concentration, application route and severity of salinity, so the research does not support one universal treatment regime.

It does, however, show that the effects observed in individual experiments form part of a much broader and repeatable plant-stress response.

Trehalose and ion balance

One of the most interesting effects of trehalose under salinity is its relationship with sodium and potassium regulation.

Plants need potassium for functions including:

• enzyme activation
• protein synthesis
• stomatal regulation
• photosynthesis
• osmotic control
• transport of metabolites.

Sodium can interfere with many of these processes.

Maintaining potassium while limiting the disruptive effects of sodium is therefore particularly important in saline environments.

Detailed tomato research has shown that externally applied trehalose can influence this balance.[3,4]

In one study, tomato seedlings were exposed to 150 mM sodium chloride and treated foliarly with 10 mM trehalose.[3]

Trehalose increased the selectivity of potassium relative to sodium transport and altered the expression of genes involved in ion transport, including members of the SOS, NHX and HKT systems.[3]

The researchers also found changes in the distribution of other mineral elements including calcium, magnesium, iron, manganese, zinc and copper.[3]

These results suggest that trehalose's effect under salinity is not simply about retaining water.

It can also influence the plant's ability to maintain mineral-ion homeostasis.

Evidence from tomato

Tomato has become one of the most extensively studied crops for understanding the mechanisms behind trehalose-mediated salt tolerance.

A separate 2022 experiment compared tomato seedlings grown under normal conditions, trehalose alone, salt stress, and salt stress combined with trehalose.[4]

Salt treatment caused:

• reduced plant growth
• increased sodium
• lower potassium
• a sharply reduced potassium-to-sodium ratio
• increased hydrogen peroxide
• increased superoxide radicals
• lipid membrane damage
• impaired photosynthesis.[4]

Foliar application of trehalose improved plant biomass and photosynthetic performance while increasing potassium and restoring a more favourable potassium-to-sodium balance.[4]

Trehalose also increased the activity of antioxidant enzymes including:

• superoxide dismutase
• peroxidase
• catalase.[4]

At the same time, the accumulation of reactive oxygen species was reduced.

The researchers also detected changes in enzymes and genes associated with the plant's own trehalose metabolic pathway, suggesting that externally supplied trehalose can influence endogenous carbohydrate and stress signalling rather than acting purely as an external osmoprotectant.[4]

The concentration matters

The tomato research also provides an important warning against assuming that increasing the amount of trehalose will automatically improve results.

Researchers compared trehalose concentrations of 5, 10 and 25 mM under salt stress.[4]

The strongest overall response occurred around 10 mM under the conditions tested.

At 25 mM, some growth effects became less favourable.

This reinforces a recurring finding across agricultural trehalose research:

Trehalose is biologically active, and the optimum concentration depends on the crop, growth stage, stress intensity and application method.

Experimental concentrations should therefore not be converted directly into universal farm mixing instructions.

Protecting photosynthesis under salt stress

Salinity can substantially impair photosynthesis.

Stomata may close, chlorophyll can be damaged, electron transport becomes less efficient and the biochemical reactions responsible for fixing carbon dioxide can be inhibited.

Trehalose appears to protect several parts of this system.

In tomato, salt stress substantially reduced:

• net photosynthetic rate
• stomatal conductance
• transpiration
• Calvin-cycle enzyme activity
• photosynthetic electron transport.[3]

Trehalose treatment partially reversed these effects.

Researchers found improved activity of enzymes including Rubisco and other enzymes involved in the Calvin cycle, alongside better chloroplast structure and photosynthetic electron transport.[3]

This provides a plausible route through which cellular stress protection can translate into improved plant growth.

The 2025 salinity review similarly identifies protection of chloroplast integrity, photosystems and photosynthetic enzymes as an important component of trehalose-mediated salt tolerance.[2]

Trehalose, ROS and antioxidant defence

Salinity frequently causes excessive production of reactive oxygen species, commonly abbreviated ROS.

These molecules include hydrogen peroxide and superoxide radicals.

At controlled levels, ROS are involved in normal cellular signalling.

When they accumulate excessively, however, they can damage:

• membrane lipids
• proteins
• enzymes
• chloroplasts
• DNA
• other cellular structures.

Plants contain antioxidant systems designed to keep ROS under control.

Trehalose treatment has repeatedly been associated with greater antioxidant capacity under salt stress.[1,2,4]

In tomato, foliar trehalose increased superoxide dismutase, peroxidase and catalase activity and altered expression of genes associated with these antioxidant enzymes.[4]

Research in maize, rice and wheat has reported similar effects.[5–9]

At the same time, trehalose-treated plants frequently show lower:

• hydrogen peroxide
• malondialdehyde
• lipid peroxidation
• membrane damage.[1,4–9]

This makes antioxidant regulation one of the most consistent mechanisms in the current salinity literature.

Evidence from maize

Maize research has added another layer to the evidence.

A recent study combined conventional plant physiology with transcriptomic analysis to investigate how trehalose changes the response of maize to salt stress.[5]

Trehalose treatment increased:

• maize biomass
• antioxidant-enzyme activity
• photosynthetic performance

while reducing:

• hydrogen peroxide
• the sodium-to-potassium ratio.[5]

The researchers also observed increased secretion of organic acids from maize roots.

These changes were associated with modification of the root environment and reduced sodium toxicity.[5]

At the genetic level, trehalose altered expression in pathways associated with:

• photosynthesis
• abscisic-acid signalling
• sugar metabolism.[5]

This is important because it supports a broader interpretation of trehalose as a stress-response regulator, rather than simply a physical protectant.

Another maize study using 10 mM trehalose under 150 mM NaCl similarly found improvements in growth and antioxidant activity together with lower ROS, lipid damage and sodium-to-potassium ratios.[6]

Together, these results show that the salt-stress response observed in tomato is also evident in a major cereal crop.

Trehalose in rice under salinity

Rice is particularly sensitive to salt stress, making it an important crop for this field of research.

A study involving two rice varieties investigated seeds soaked in 25 mM trehalose before plants were exposed to saline conditions.[7]

Salinity reduced photosynthetic pigments and carbohydrate metabolism while increasing several stress-related solutes.

Trehalose treatment helped alleviate these effects and increased antioxidant-enzyme activity and osmotic adjustment.[7]

Other rice research has investigated foliar trehalose at the tillering stage across multiple varieties and salinity levels.

A 2023 experiment involving three lowland rice varieties found that trehalose altered physiological, biochemical and agronomic responses to increasing sodium chloride exposure.[8]

More recently, field trials conducted on saline soils in Egypt during the 2024 and 2025 seasons reported improved relative water content and lower hydrogen-peroxide accumulation following foliar trehalose treatment.[10]

The growing rice literature therefore extends the evidence beyond short-term controlled studies and into increasingly realistic crop environments.

Trehalose in wheat

Trehalose has also been studied in wheat under salinity.

In one study, plants grown under saline irrigation were treated foliarly with 10 or 50 mM trehalose.[9]

Salt stress reduced shoot growth and increased:

• hydrogen peroxide
• lipid peroxidation
• lipoxygenase activity.

Trehalose improved growth measurements while reducing several markers of oxidative damage and increasing the accumulation of soluble sugars and other osmoprotective compounds.[9]

More recent research has also investigated trehalose seed pretreatment in wheat and found reductions in salt-induced lipid peroxidation alongside changes in antioxidant and secondary-metabolite responses.[11]

The precise treatment and response again vary between experiments, but the direction is consistent with the broader salinity literature.

Osmotic adjustment

Salinity causes a problem similar to drought at the cellular level:

water becomes more difficult for the plant to obtain.

Plants respond by accumulating compatible solutes that help maintain osmotic balance.

These can include:

• soluble sugars
• proline
• glycine betaine
• amino acids
• trehalose itself.

Trehalose may contribute directly to this process while also influencing the accumulation and metabolism of other osmolytes.[2,4,7,9]

In tomato, externally supplied trehalose increased several carbohydrate and osmotic compounds during salt stress.[4]

Similar responses have been observed in rice and wheat.[7,9]

This helps explain why salinity and drought show several overlapping responses to trehalose, even though the stresses are not identical.

Salinity is more than water stress

Despite that overlap, drought and salinity should not be treated as the same problem.

Drought primarily restricts available water.

Salinity combines osmotic stress with ion toxicity and nutritional imbalance.

This makes trehalose's effects on sodium and potassium particularly important.

A successful salt-stress treatment therefore needs to help plants manage both:

1. difficulty obtaining water, and
2. accumulation of potentially harmful ions.

The current research suggests that trehalose can influence both parts of this response.[2–5]

Root responses may be important

Much of the early agricultural literature concentrated on leaves and shoots.

More recent maize research suggests that roots may be equally important.

Trehalose treatment has been associated with:

• lower root sodium-to-potassium ratios
• increased root antioxidant activity
• altered organic-acid secretion
• changes in root metabolic pathways.[5]

Because roots are the first tissues exposed to saline soil, these responses could prove particularly important in the development of practical agricultural applications.

The root-zone effects of trehalose remain an area where further research is likely to be valuable.

Plant signalling and ABA

Trehalose metabolism is closely linked to plant signalling.

Recent research increasingly connects externally applied trehalose with changes in pathways involving abscisic acid, commonly abbreviated ABA.[2,5]

ABA is a major plant stress hormone involved in:

• stomatal regulation
• water conservation
• root development
• ion transport
• expression of stress-response genes.

The maize transcriptomic study found that trehalose affected genes associated with ABA signalling during salinity stress.[5]

The 2025 review similarly identifies interactions between trehalose metabolism and hormonal signalling as an important part of plant adaptation to salt.[2]

This area is still developing, but it reinforces the idea that trehalose can act as more than a passive compatible solute.

How is trehalose applied under salinity stress?

Salinity research has used several application methods.

Foliar application

Trehalose solution is sprayed onto the leaves.

This is common in tomato, maize and wheat research and is the dominant application method across the wider agricultural trehalose literature.[1,3–6,9]

Seed treatment

Seeds can be soaked or primed with trehalose before planting.

This approach has been investigated in rice and wheat.[7,11]

Root or nutrient-solution application

Trehalose can also be supplied through the root environment in hydroponic and controlled studies.

Different application routes may produce different physiological effects.

There is currently no evidence supporting one universal method for all crops.

How much trehalose is used?

Published concentrations vary considerably.

Representative salinity experiments include:

These are experimental treatments, not general agricultural recommendations.[3–9]

The appropriate concentration depends on factors including:

• crop species
• cultivar
• growth stage
• salinity level
• application route
• timing
• frequency
• growing environment
• formulation.

The tomato studies demonstrate particularly clearly why concentration matters: the strongest response occurred at an intermediate treatment rather than the highest concentration tested.[4]

Commercial development therefore requires crop-specific optimisation.

Can trehalose improve growth under salinity?

The evidence indicates that it can mitigate some of the growth suppression caused by salt stress.

Trehalose-treated plants in tomato, maize, rice and wheat studies have shown improvements in variables including:

• shoot growth
• root growth
• biomass
• leaf area
• chlorophyll
• plant water status.[3–9]

The 2026 meta-analysis also found positive overall effects on multiple growth characteristics across abiotic stresses.[1]

However, this does not mean that trehalose removes the underlying salinity problem.

Extremely saline soils can still restrict or prevent crop production.

The realistic agricultural objective is to improve the plant's tolerance of salinity, helping preserve physiological function and growth when salt stress would otherwise cause greater damage.

Can trehalose improve yield in saline conditions?

Yield evidence is promising but less extensive than physiological evidence.

Many salinity experiments are performed on seedlings or young plants because these systems allow detailed study of physiological mechanisms.

Field studies increasingly include agronomic outcomes, particularly in cereals such as rice.

Across the broader 2026 meta-analysis, trehalose produced a significant positive overall effect on grain yield, although this result combines several different abiotic stresses rather than salinity alone.[1]

It would therefore be inappropriate to claim a universal percentage yield increase from trehalose under saline conditions.

The evidence currently supports a more defensible proposition:

Trehalose can reduce several of the physiological constraints caused by salinity, creating the potential to protect crop growth and productivity where salt stress is limiting performance.

Can trehalose reclaim saline soil?

No.

Trehalose should not be confused with a physical or chemical soil-remediation treatment.

It does not remove sodium salts from soil.

Management of saline land may require measures such as:

• improved drainage
• leaching
• irrigation management
• soil amendments
• crop selection
• salt-tolerant varieties.

Trehalose is better understood as a potential plant biostimulant that helps the crop respond to salinity, rather than as a product that desalinates the soil.

Interestingly, recent maize research indicates that trehalose can alter root exudation and aspects of the immediate root environment.[5]

That may have important implications for saline agriculture, but it is different from removing salts from the soil itself.

From laboratory research to crop application

The evidence base for trehalose under salinity has developed considerably.

It now includes:

• multiple crop species
• foliar treatments
• seed treatments
• physiological studies
• biochemical studies
• ionomics
• gene-expression research
• transcriptomics
• pot and field experiments
• a dedicated salinity review
• a wider meta-analysis containing 15 salinity studies.[1,2]

The strongest recurring effects involve:

ion homeostasis
Maintaining a more favourable potassium-to-sodium balance.

photosynthetic protection
Helping preserve chloroplast and photosystem function.

antioxidant defence
Increasing the plant's capacity to control excessive reactive oxygen species.

osmotic adjustment
Supporting water relations and compatible-solute metabolism.

cellular protection
Reducing membrane and oxidative damage.

plant growth
Mitigating some of the reductions in biomass and development caused by salinity.

Together, these mechanisms provide a credible biological basis for developing trehalose as an agricultural ingredient for crops exposed to salt stress.

Agricultural-grade trehalose

Agricultural use is already moving beyond academic experimentation.

Nagase supplies agricultural-grade trehalose for plant-biostimulant and other agricultural applications and specifically identifies salinity among the abiotic stresses relevant to trehalose.[12]

Its agricultural positioning also includes:

• seed coatings
• microbial inoculants
• biological formulations
• direct plant-biostimulant applications.[12]

Practical products nevertheless require appropriate formulation, efficacy testing and regulatory consideration for the intended market.

Trehalose for saline agriculture and crop development

The agricultural challenge created by salinity is likely to remain substantial.

The accumulated evidence increasingly supports trehalose as one potential tool for helping crops cope with saline growing conditions.

It cannot remove salt from the soil, and there is no single application rate suitable for every crop.

But research across multiple species now supports a consistent proposition:

Trehalose can help plants maintain ion balance, photosynthesis, antioxidant defence and cellular function under salinity stress, reducing some of the physiological damage caused by saline conditions.

This makes salinity one of the strongest areas of current research into agricultural trehalose, alongside drought and biological-formulation stabilisation.

Trehalose for agriculture and plant science

Trehalose UK is developing its support for agricultural and plant-science applications of genuine Japanese trehalose.

We welcome enquiries from:

• growers
• agronomists
• crop researchers
• plant-biostimulant manufacturers
• agricultural formulators
• universities
• agricultural biotechnology businesses.

For technical requirements, development quantities, product-grade enquiries or commercial supply, contact:

sales@trehalose.co.uk

For a broader overview, read:

Trehalose in Agriculture: Uses, Benefits & Research

and:

Trehalose for Drought & Water Stress in Plants

References & further reading

[1] Adrielle Cristine Domingos Adão, Antônio Rodrigues da Cunha Neto, Marina Wolowski, and Thiago Corrêa de Souza. 2026. “Exogenous Trehalose Mitigates Abiotic Stress in Plants by Improving Morphophysiology: A Meta-Analysis.” Journal of Crop Science and Biotechnology 29: 547–565. Systematic review and meta-analysis of 52 studies, including 15 involving salinity stress. Springer Nature
Read the study

[2] “Trehalose and Its Role in Plant Adaptation to Salinity Stress.” 2025. Plant Science 357: 112533. Dedicated review of trehalose metabolism, osmotic adjustment, antioxidant defence, photosynthetic protection, ion regulation and signalling under salinity stress. ScienceDirect
Read the review

[3] Yan Yang, Jianming Xie, Jing Li, et al. 2022. “Trehalose Alleviates Salt Tolerance by Improving Photosynthetic Performance and Maintaining Mineral Ion Homeostasis in Tomato Plants.” Frontiers in Plant Science 13: 974507. Detailed investigation of photosynthesis, chloroplast function and mineral-ion distribution following 10 mM foliar trehalose under 150 mM NaCl. Frontiers
Read the study

[4] Yan Yang, Yandong Yao, Jing Li, et al. 2022. “Trehalose Alleviated Salt Stress in Tomato by Regulating ROS Metabolism, Photosynthesis, Osmolyte Synthesis, and Trehalose Metabolic Pathways.” Frontiers in Plant Science 13: 772948. Investigates concentration effects, antioxidant responses, osmolytes and potassium-to-sodium homeostasis. Frontiers
Read the study

[5] Jingyi He and Hongliang Tang. 2024. “Combined Physiological and Transcriptomic Analyses of the Effects of Exogenous Trehalose on Salt Tolerance in Maize (Zea mays L.).” Plants 13, no. 24: 3506. Examines biomass, antioxidants, sodium/potassium balance, root organic-acid secretion and stress-related gene expression. MDPI
Read the study

[6] “Trehalose Protects Maize Plants from Salt Stress and Phosphorus Deficiency.” 2019. Study of two maize hybrids exposed to 150 mM NaCl, phosphorus deficiency and combined stress, with or without 10 mM trehalose. Trehalose improved growth and reduced sodium/potassium imbalance, ROS and membrane damage. PubMed Central (PMC)
View the PubMed record

[7] M. M.-S. Abdallah, Z. A. Abdelgawad, and H. M. S. El-Bassiouny. 2016. “Alleviation of the Adverse Effects of Salinity Stress Using Trehalose in Two Rice Varieties.” South African Journal of Botany 103: 275–282. Investigates 25 mM trehalose seed treatment under saline conditions in two rice varieties. ScienceDirect
Read the study

[8] Felisberto Amaral Soares et al. 2023. “Exogenous Trehalose Application in Rice to Mitigate Saline Stress at the Tillering Stage.” Pesquisa Agropecuária Tropical 53. Study of three lowland rice varieties exposed to different salinity levels and foliar trehalose treatments. SciELO
Read the study

[9] “Physiological Role of Trehalose on Enhancing Salinity Tolerance of Wheat Plant.” 2019. Bulletin of the National Research Centre. Investigates foliar trehalose under saline irrigation and effects on growth, oxidative damage and osmoprotective metabolites. Springer Nature
Read the study

[10] Amira Okasha, M. Negm, Dalia El-Sharnobi, and B. Zayed. 2026. “Effect of Trehalose Exogenous Application on Physiological Traits, Productivity and Grain Quality of Some Rice Genotypes under Salinity Stress.” Field experiments conducted on saline soils during the 2024 and 2025 growing seasons. FAO AGRIS

[11] “Enhancing Salt Stress Tolerance in Wheat (Triticum aestivum) Seedlings: Insights from Trehalose and Mannitol.” 2024. Study comparing trehalose and mannitol seed pretreatment under 150 mM NaCl stress. PubMed
View the PubMed record

[12] NAGASE Europe. “Trehalose for Agriculture.” Current manufacturer information on agricultural-grade trehalose for plant biostimulants, microbial inoculants, seed coatings and biological formulations, including use under abiotic stresses such as salinity. NAGASE | Europe
NAGASE agricultural information