Drought is one of the most extensively studied agricultural applications of trehalose.

When plants experience insufficient water, the effects extend far beyond simple dehydration. Water deficit can restrict photosynthesis, reduce growth, damage cellular membranes, increase oxidative stress and ultimately reduce crop productivity.

Research increasingly suggests that externally applied trehalose can help plants maintain physiological function under these conditions.

A major 2026 meta-analysis identified 20 separate studies of trehalose under water-deficit stress, making drought the largest single stress category within the agricultural trehalose literature.[1]

Across the wider evidence base, trehalose improved plant water status, photosynthesis, antioxidant activity, growth and several measures associated with stress tolerance.[1]

For agriculture, this makes drought and water stress one of the most promising areas for the development of trehalose-based biostimulant technologies.

What happens to plants during drought?

Plants depend on water for virtually every aspect of growth.

As soil moisture becomes restricted, plants begin to close their stomata to reduce water loss. This helps conserve water, but also limits the carbon dioxide available for photosynthesis.

As drought becomes more severe, plants can experience:

• reduced photosynthesis
• lower chlorophyll content
• loss of cellular water
• reduced leaf expansion
• slower root and shoot growth
• oxidative stress
• damage to cellular membranes
• disrupted nutrient movement
• reduced flowering and grain or fruit development.

Drought also increases the production of reactive oxygen species, or ROS.

These molecules are a normal part of plant metabolism, but excessive accumulation can damage proteins, lipids, membranes and the photosynthetic machinery.

Successful drought tolerance therefore requires more than simply retaining water. Plants must also protect their cells, maintain photosynthesis and manage oxidative stress.

Trehalose appears to influence several of these processes simultaneously.[1]

What does the research show?

The strongest overall evidence comes from the 2026 systematic review and meta-analysis of externally applied trehalose under abiotic stress.[1]

Researchers screened 659 publications and ultimately included 52 eligible studies published between 2005 and 2024.

Of those:

20 studies investigated water deficit or drought stress.

The analysis found that trehalose produced beneficial effects across several important drought-related measurements.[1]

Under water deficit, externally applied trehalose was associated with improvements in:

• relative water content
• water-use efficiency
• photosynthetic rate
• stomatal conductance
• transpiration
• intercellular carbon dioxide
• chlorophyll
• antioxidant activity
• shoot growth
• root growth.[1]

Trehalose treatment was also associated with reductions in indicators of cellular damage, including hydrogen peroxide accumulation, lipid peroxidation and membrane permeability.[1]

These effects point towards a broad stress-protection response rather than one isolated mechanism.

Trehalose can help plants maintain water status

One of the most important findings is trehalose's effect on relative water content.

Relative water content measures the amount of water contained within plant tissue relative to the amount it could hold when fully hydrated.

It is therefore a useful indicator of how effectively a plant maintains its hydration during drought.

The 2026 meta-analysis found a significant positive effect of trehalose on relative water content under water-deficit conditions.[1]

It also identified improved water-use efficiency under water deficit.[1]

This does not mean trehalose somehow supplies water to the plant.

Instead, its effects appear to involve a combination of osmotic regulation, cellular protection and changes in the plant's physiological response to drought.

Trehalose is therefore better understood as helping plants manage water stress more effectively, rather than as replacing irrigation.

Evidence from maize under field water stress

One of the important early field studies investigated two maize cultivars grown under restricted irrigation.[2]

Researchers applied 30 mM trehalose as a foliar spray and compared treated and untreated plants under different water-deficit regimes.

Water stress reduced:

• biomass production
• photosynthetic performance
• plant-water relations.

Trehalose treatment mitigated several of these effects.

Treated plants showed improvements in growth, photosynthetic characteristics and water relations, alongside changes in antioxidant defence.[2]

The importance of this study is that it was conducted under field water-deficit conditions, rather than exclusively in controlled laboratory conditions.

It provided early evidence that externally applied trehalose could influence the response of a major cereal crop to agricultural drought.

Trehalose in sunflower

More recent research has demonstrated similar effects in sunflower.

A 2022 study subjected two sunflower cultivars to drought at 60% field capacity and applied foliar trehalose at 10, 20 or 30 mM.[3]

Drought reduced plant growth, relative water content and yield-related measurements.

Trehalose treatment improved:

• relative water content
• shoot and root growth
• soluble sugars
• soluble proteins
• antioxidant enzyme activity
• mineral status
• yield characteristics.[3]

It also reduced relative membrane permeability, indicating better maintenance of cellular membrane integrity.[3]

Interestingly, the strongest overall response occurred with the 10 mM treatment, rather than the higher concentrations.[3]

That finding reinforces an important principle:

More trehalose is not automatically better.

The appropriate concentration depends on crop, stress intensity, application method and growing conditions.

Trehalose in quinoa

Field research in quinoa provides another useful example.

Researchers grew quinoa under irrigation and water-deficit conditions and applied foliar trehalose at relatively low concentrations of 0.1 and 0.5 mM.[4]

Drought increased hydrogen peroxide and lipid peroxidation — indicators of oxidative stress.

Trehalose treatment reduced both while increasing the activity of antioxidant enzymes including:

• superoxide dismutase
• catalase
• peroxidase
• ascorbate peroxidase.[4]

Trehalose also influenced soluble sugars and other compounds involved in osmotic adjustment.

The higher 0.5 mM treatment generally produced the stronger response under the conditions used in that experiment.[4]

Separate field work in quinoa also reported improvements in growth, photosynthetic pigments, seed yield and several measures of seed quality following trehalose treatment under water deficit.[5]

Together, these studies demonstrate that the drought-related effects of trehalose are not confined to a single crop or one experimental system.

Protecting photosynthesis during drought

Drought commonly reduces photosynthesis before visible plant damage becomes severe.

As stomata close and cellular water availability falls, the plant's photosynthetic machinery becomes increasingly vulnerable.

Trehalose appears to help protect this system.

The 2026 meta-analysis found beneficial effects on photosynthetic rate and several associated gas-exchange measurements under water deficit.[1]

Research in winter wheat has examined this process in considerably greater detail.

Scientists subjected wheat seedlings to heat and drought stress and investigated the effect of trehalose on photosystem II, the light-capturing system that plays a central role in photosynthesis.[6]

Trehalose pretreatment helped maintain:

• maximum photochemical efficiency
• electron transport through photosystem II
• cyclic electron flow
• the proton gradient across the thylakoid membrane
• ATPase activity.[6]

The researchers concluded that trehalose helped reduce stress-induced inhibition of photosystem II.[6]

This supports the broader agricultural observation that trehalose treatment can help preserve photosynthetic function when plants are exposed to water stress.

Antioxidant defence under drought

Drought does not simply deprive the plant of water.

It also creates oxidative stress.

When reactive oxygen species accumulate faster than the plant can neutralise them, they begin to damage membranes, proteins and other cellular components.

Plants counter this using antioxidant enzymes.

Across the drought studies analysed in 2026, trehalose significantly increased the activity of several important antioxidant systems.[1]

These included:

• superoxide dismutase
• catalase
• peroxidase.[1]

The meta-analysis also found reduced:

• hydrogen peroxide
• lipid peroxidation
• membrane permeability

under water-deficit conditions.[1]

Similar responses have been observed directly in maize, sunflower and quinoa.[2–4]

This suggests that one of the important functions of externally applied trehalose is helping plants strengthen the biochemical systems used to control oxidative damage.

Protecting cellular membranes

Cell membranes are particularly vulnerable during dehydration.

When water availability falls, the physical organisation of membrane lipids can be disrupted. Oxidative stress can then compound the damage.

Trehalose has long been recognised for its ability to interact with water and help stabilise biological structures during dehydration.

In drought-stressed plants, this physical property appears to combine with changes in antioxidant metabolism.

The result is reflected in reduced membrane permeability and lower lipid peroxidation across the research literature.[1]

The sunflower study, for example, found that trehalose substantially reduced relative membrane permeability under drought stress.[3]

Maintaining membrane integrity is important because damaged membranes interfere with normal cellular function, nutrient balance and plant metabolism.

Osmotic adjustment and protective sugars

Plants naturally accumulate small soluble molecules when exposed to drought.

These substances, often called compatible solutes or osmolytes, help cells adjust to declining water availability without interfering with normal metabolism.

Trehalose can participate in this process directly, but externally applied trehalose can also alter the accumulation and metabolism of other carbohydrates and osmolytes.

In quinoa, for example, trehalose treatment influenced levels of:

• glucose
• sucrose
• total soluble sugars
• endogenous trehalose
• proline
• free amino acids.[4]

The precise response varies between species and experimental conditions.

Trehalose therefore appears to operate not simply as an externally supplied osmolyte but as part of a broader adjustment in plant carbohydrate and stress metabolism.

Can trehalose protect crop growth and yield?

Improving biochemical stress responses is useful only if it eventually helps protect plant performance.

The evidence here is encouraging, although responses vary by crop and environment.

The 2026 meta-analysis found beneficial overall effects of externally applied trehalose on:

• shoot length
• shoot fresh weight
• shoot dry weight
• root length
• root fresh weight
• plant height
• leaf area
• tiller number
• leaf number
• grain yield.[1]

Not every measurement improved. For example, the overall analysis did not identify an improvement in 100-grain weight.[1]

Individual drought studies nevertheless provide evidence that physiological protection can translate into better crop performance.

In sunflower, trehalose improved growth and yield characteristics under drought.[3]

In quinoa, foliar trehalose improved seed yield and several yield-related characteristics under water-deficit conditions.[5]

In wheat, a study using 10 mM foliar trehalose found improvements in several growth, biochemical and yield measurements under water stress, although maltose performed better than trehalose for a number of the parameters investigated.[7]

That last result is useful because it demonstrates that trehalose should not be treated as universally superior to every alternative biostimulant.

Its value depends on the crop, objective, formulation and growing conditions.

How is trehalose applied under drought conditions?

Most agricultural trehalose research has used foliar application.

Across the complete 2026 abiotic-stress evidence base, 34 of 52 studies used foliar treatment, compared with 15 using root application and three using seed priming.[1]

For drought specifically, published experimental concentrations vary substantially.

Examples include:

These values illustrate the range of experimental approaches; they are not interchangeable agricultural recommendations.[2–5,7]

The appropriate concentration can depend on:

• crop species
• cultivar
• plant growth stage
• severity and duration of water deficit
• foliar versus root application
• environmental conditions
• other ingredients in the formulation
• timing and frequency of treatment.

The sunflower research is particularly instructive: the lowest concentration tested, 10 mM, produced the strongest overall result.[3]

A commercial product therefore needs to be formulated and validated for its intended crop and application rather than simply selecting the highest concentration reported in the literature.

Trehalose is not a replacement for irrigation

The research should also be interpreted correctly.

Trehalose does not create water, nor can it compensate indefinitely for severe drought.

Its potential agricultural role is as a biostimulant helping plants tolerate periods of water stress more effectively.

That distinction matters.

A crop with no available water will eventually fail irrespective of trehalose treatment.

The more realistic agricultural objective is to help protect plant function during:

• temporary water shortages
• intermittent drought
• reduced irrigation
• periods of unusually high evaporative demand
• other conditions where plant water stress limits performance.

This is also why measurements such as relative water content, water-use efficiency, photosynthetic activity and antioxidant defence are so important in the research.

They show how plants respond while water availability is restricted.

From research to agricultural application

The evidence for trehalose and drought has progressed considerably.

It now includes:

• controlled plant studies
• field experiments
• multiple crop species
• physiological and biochemical research
• photosynthetic-mechanism studies
• yield measurements
• a systematic meta-analysis covering 20 water-deficit studies.[1]

The evidence does not yet support one universal application rate or guaranteed percentage improvement in drought tolerance.

What it does support is a clear underlying proposition:

Externally applied trehalose can help plants maintain water status, protect photosynthesis, strengthen antioxidant defence and reduce cellular damage during drought and water-deficit stress.

That makes trehalose an increasingly interesting ingredient for the development of plant biostimulants and crop-stress management technologies.

Agricultural-grade trehalose

Agricultural use of trehalose is now moving beyond academic research.

Nagase supplies dedicated agricultural-grade trehalose for applications including plant biostimulants, seed coatings and biological agricultural formulations.[8]

Nagase Viita is also actively investigating direct agricultural applications of trehalose internationally, including its potential to support crops exposed to drought and other challenging environmental conditions.[9]

For commercial use, the appropriate agricultural grade, formulation, concentration and regulatory position should be established for the intended application.

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
• agricultural formulators
• biostimulant manufacturers
• universities and research organisations
• 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

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. DOI: 10.1007/s12892-026-00355-1. Systematic review and meta-analysis of 52 studies, including 20 studies involving water deficit.
Read the study

[2] Qasim Ali and Muhammad Ashraf. 2011. “Induction of Drought Tolerance in Maize (Zea mays L.) due to Exogenous Application of Trehalose: Growth, Photosynthesis, Water Relations and Oxidative Defence Mechanism.” Journal of Agronomy and Crop Science 197, no. 4: 258–271. DOI: 10.1111/j.1439-037X.2010.00463.x. Field study of foliar trehalose under water-deficit conditions in maize.
Read the study

[3] Firdos Kosar, Khalid S. Alshallash, Nudrat Aisha Akram, Muhammad Sadiq, Muhammad Ashraf, Dalal Hussien M. Alkhalifah, Arafat Abdel Hamed Abdel Latef, and Amr Elkelish. 2022. “Trehalose-Induced Regulations in Nutrient Status and Secondary Metabolites of Drought-Stressed Sunflower (Helianthus annuus L.) Plants.” Plants 11, no. 20: 2780. DOI: 10.3390/plants11202780. Study of 10–30 mM foliar trehalose under drought stress in two sunflower cultivars.
Read the study

[4] Mervat Shamoon Sadak, Hala Mohammed Safwat El-Bassiouny, and Mona Gergis Dawood. 2019. “Role of Trehalose on Antioxidant Defense System and Some Osmolytes of Quinoa Plants under Water Deficit.” Bulletin of the National Research Centre 43: 5. DOI: 10.1186/s42269-018-0039-9. Field research examining foliar trehalose, antioxidant defence and osmotic responses in drought-stressed quinoa.
Read the study

[5] Mona Gergis Dawood. 2018. “Improving Drought Tolerance of Quinoa Plant by Foliar Treatment of Trehalose.” Agricultural Engineering International: CIGR Journal, Special Issue: 132–143. Field experiments examining trehalose effects on quinoa growth, photosynthetic pigments, yield and seed composition under water deficit.
Read the study

[6] Y. Luo, Y. Xie, D. He, W. Wang, and S. Yuan. 2021. “Exogenous Trehalose Protects Photosystem II by Promoting Cyclic Electron Flow under Heat and Drought Stresses in Winter Wheat.” Plant Biology 23, no. 5: 770–776. DOI: 10.1111/plb.13277. Mechanistic investigation of photosystem II protection by trehalose under drought and heat stress.
Read the study

[7] Hala Mohammed Safwat El-Bassiouny, Mervat Shamoon Sadak, and Amira A. Abdallah. 2016. “Effect of Maltose and Trehalose on Growth, Yield and Some Biochemical Components of Wheat Plant under Water Stress.” Annals of Agricultural Sciences 61, no. 2: 267–274. DOI: 10.1016/j.aoas.2016.05.002. Comparison of foliar trehalose and maltose under water stress in wheat.
Read the study

[8] NAGASE Europe. “Trehalose for Agriculture.” Current information on agricultural-grade trehalose for plant biostimulants, seed coatings, microbial inoculants and biological formulations.
NAGASE agricultural information

[9] Nagase Viita Co., Ltd. 2026. “Trehalose-Based Agricultural Support Project Selected for JICA Biz Program (FY2025).” Current development programme investigating trehalose as a direct agricultural biostimulant and as a stabilising ingredient for biological formulations.
Read the Nagase announcement