Exogenous Application Of Glycinebetaine Research Articles

Exogenous glycine betaine alleviates water-deficit stress in Indian pennywort (Centella asiatica) under greenhouse conditions.

Centella asiatica (Indian pennywort) is a green leafy vegetable containing centelloside' (triterpenoid), a key phytochemical component in traditional medicine. Being a glycophytic species, they exhibit decline in growth performance and yield traits when subjected to water-deficit (WD) conditions. Glycine betaine (GB) is a low molecular-weight organic metabolite that plays a crucial role in abiotic stress conditions in higher plants. The objective of this study was to investigate the potential of GB in alleviating water-deficit stress (in terms of morphological and physiological responses) in two different genotypes of Indian pennywort, "Nakhon Pathom" (NP; high centelloside-yielding genotype) and "Pathum Thani" (PT; low centelloside-yielding genotype). The genotypes of Indian pennywort were propagated by stolon cutting and transplanted into plastic bags containing 2kg of garden soil. At the flower-initiation stage (30days after transplantation), uniform plant material was treated exogenously with 0 (control), 25, and 50mMGB at 100mL per plant (one-time foliar spray) and then divided into two groups, 1) well watered (WW; irrigated daily with 400mL fresh water; 98% field capacity) and 2) water deficit (WD; withheld water for 14days; 72% field capacity). Foliar application of GB (25mM) significantly improved leaf osmotic potential in NP under WD conditions via osmotic adjustment by free proline and fructose. Differences in leaf temperature (Tleaf) between WD and WW in NP were maximized (+ 1.93°C) and the gap of Tleaf was reduced in the case of 25-50mMGB application. Similarly, crop water stress index (CWSI) in NP and PT plants under WD condition was significantly increased by 1.95- and 1.86-fold over the control, respectively; however, it was significantly decreased by exogenous GB application. Increasing Tleaf and CWSI in drought-stressed plants was closely related to stomatal closure, leading to reduced gas exchange parameters, i.e., stomatal conductance (gs), transpiration rate (E), net photosynthetic rate (Pn), and intercellular CO2 concentration (Ci), and consequently decreased plant biomass and total centelloside yield. Overall physiological, morphological, and secondary metabolite traits were enhanced in NP under WD conditions using 25mMGB exogenous application compared with the control. The study highlights the significance of GB in Indian pennywort production under limited water irrigation (water deficit) with higher vegetable yield and phytochemical stabilization.

Foliar application of glycine betaine to ameliorate lead toxicity in barley plants by modulating antioxidant enzyme activity and biochemical parameters

Lead (Pb) toxicity is a major problem in agricultural soil that negatively affects plant growth and development. Glycine betaine (GB) is an effective compatible solute that resists abiotic stress and plays an important role to mitigate various stresses. The present study is the first of its kind on the application of GB to mitigate Pb toxicity on barley cultivars. To elucidate the role of GB in mitigating Pb toxicity of three concentrations (15 mM, 25 mM, and 35 mM) in two barley varieties (BH-959 and BH-946) with and without foliar application of GB (2 mM) was examined. The study found that increasing Pb concentration significantly (p < 0.05) reduced the level of primary metabolites viz. photosynthetic pigments, protein, and carbohydrates in both cultivars upto 42.4%, 38.4% and 39% respectively. However malondialdehyde content, proline content, and antioxidant enzyme activity (SOD, CAT, and POX) were found to increased significantly (p < 0.05) as compared to control treatment upto 83.4%, 83.2% and 51% respectively. In contrast, the application of GB led to significantly (p < 0.05) improved physio-biochemical parameters as well as antioxidant enzyme activity (53%) and reduced oxidative stress along with malondialdehyde content (14.42%) in both varieties. An increment in these parameters revealed that exogenous application of GB (2 mM) significantly improves Pb (up to 35 mM) toxicity in barley plants and its use may be beneficial for crops susceptible to Pb toxicity to improve growth and yield.

Effects of Exogenous Application of Glycine Betaine and Proline on Productivity of Valencia Orange Trees Grown in a Saline Soil

Effects of Exogenous Application of Glycine Betaine and Proline on Productivity of Valencia Orange Trees Grown in a Saline Soil

Mitigation the Adverse Effects of Salinity on Red Bean Plants via Exogenous Application of Glycine Betaine, Zinc, and Manganese: Physiological and Morphological Approach

Mitigation the Adverse Effects of Salinity on Red Bean Plants via Exogenous Application of Glycine Betaine, Zinc, and Manganese: Physiological and Morphological Approach

Exogenous Application of Glycine Betaine Maintains Bioactive Compounds, Antioxidant Activity, and Physicochemical Attributes of Blood Orange Fruit During Prolonged Cold Storage.

Exogenous application of glycine betaine (GB) was evaluated on bioactive compounds, antioxidant activity, and physicochemical attributes of blood orange fruit cv. Moro at 3°C for 90 days. Vacuum infiltration (30 kPa) of GB was applied at 15 and 30 mM for 8 min. Parameters were measured after 1, 30, 60, and 90 days of storage plus 2 days at 20°C to simulate the shelf-life period. GB treatments significantly reduced weight and firmness losses in “Moro” blood orange fruit during cold storage. GB treatment maintained a higher concentration of organic acids (citric, malic, succinic, and oxalic acids) and sugars (sucrose, glucose, and fructose), especially for the higher GB doses (30 mM). During storage, GB treatments enhanced total anthocyanin concentration, total phenolic content, and total antioxidant activity. With respect to enzyme activities, the application of exogenous GB showed increases in catalase (CAT), ascorbate peroxidase, superoxide dismutase, phenylalanine ammonia-lyase, while suppressing the polyphenol oxidase activity. Overall, the most effective treatment was 30 mM GB leading to maintaining bioactive compounds, antioxidant activity, and quality in “Moro” blood orange fruit during long-term storage. The positive results would permit the use of GB as a postharvest tool to maintain the quality attributes of blood orange fruit.

Effect of glycinebetaine on metabolite profiles of cold-stored strawberry revealed by 1H NMR-based metabolomics

Glycinebetaine (GB) has long been used as a preservative for refrigerated fruits, but the effect of GB on the global metabolites of cold-stored strawberries is still unclear. In this study, the effects of exogenous application of GB on quality-related metabolites of cold-stored strawberries were investigated by nuclear magnetic resonance (NMR)-based metabolomic analysis. The results showed that the application of GB (especially at the concentration of 10 mM) on cold-stored strawberries effectively stabilized the sugars (d-xylose and d-glucose) and amino acids (tyrosine, leucine, and tryptophan) content, and lowered the acid (acetic acid) content as well. Additionally, the GB content in strawberries also increased. This implies that the appropriate concentration of GB is a natural and safe treatment, which could maintain the quality of cold-stored strawberries by regulating levels of quality-related metabolites, and the ingestion of GB-preserved strawberries may serve as a source of methyl-donor supplementation in our daily diet.

Glycine betaine modulates chromium (VI)-induced morpho-physiological and biochemical responses to mitigate chromium toxicity in chickpea (Cicer arietinum L.) cultivars

Chromium (Cr) accumulation in crops reduces yield. Here, we grew two chickpea cultivars, Pusa 2085 (Cr-tolerant) and Pusa Green 112 (Cr-sensitive), in hydroponic and pot conditions under different Cr treatments: 0 and 120 µM Cr and 120 µM Cr + 100 mM glycine betaine (GB). For plants grown in the hydroponic media, we evaluated root morphological attributes and plasma membrane integrity via Evans blue uptake. We also estimated H+-ATPase activity in the roots and leaves of both cultivars. Plants in pots under conditions similar to those of the hydroponic setup were used to measure growth traits, oxidative stress, chlorophyll contents, enzymatic activities, proline levels, and nutrient elements at the seedling stage. Traits such as Cr uptake in different plant parts after 42 days and grain yield after 140 days of growth were also evaluated. In both cultivars, plant growth traits, chlorophyll contents, enzymatic activities, nutrient contents, and grain yield were significantly reduced under Cr stress, whereas oxidative stress and proline levels were increased compared to the control levels. Further, Cr uptake was remarkably decreased in the roots and leaves of Cr-tolerant than in Cr-sensitive cultivars. Application of GB led to improved root growth and morpho-physiological attributes and reduced oxidative stress along with reduced loss in plasma membrane integrity and subsequently increase in H+-ATPase activity. An increment in these parameters shows that the exogenous application of GB improves the Cr stress tolerance in chickpea plants.

Glycinebetaine mitigates tomato chilling stress by maintaining high-cyclic electron flow rate of photosystem I and stability of photosystem II.

Glycinebetaine alleviates chilling stress by protecting photosystems I and II in BADH-transgenic and GB-treated tomato plants, which can be an effective strategy for improving crop chilling tolerance. Tomato (Solanum lycopersicum) is one of the most cultivated vegetables in the world, but is highly susceptible to chilling stress and does not naturally accumulate glycinebetaine (GB), one of the most effective stress protectants. The protective mechanisms of GB on photosystem I (PSI) and photosystem II (PSII) against chilling stress, however, remain poorly understood. Here, we address this problem through exogenous GB application and generation of transgenic tomatoes (Moneymaker) with a gene encoding betaine aldehyde dehydrogenase (BADH), which is the key enzyme in the synthesis of GB, from spinach. Our results demonstrated that GB can protect chloroplast ultramicrostructure, alleviate PSII photoinhibition and maintain PSII stability under chilling stress. More importantly, GB increased the electron transfer between QA and QB and the redox potential of QB and maintained a high rate of cyclic electron flow around PSI, contributing to reduced production of reactive oxygen species, thereby mitigating PSI photodamage under chilling stress. Our results highlight the novel roles of GB in enhancing chilling tolerance via the protection of PSI and PSII in BADH transgenic and GB-treated tomato plants under chilling stress. Thus, introducing GB-biosynthetic pathway into tomato and exogenous GB application are effective strategies for improving chilling tolerance.

Role of Glycine Betaine in the Thermotolerance of Plants

As global warming progresses, agriculture will likely be impacted enormously by the increasing heat stress (HS). Hence, future crops, especially in the southern Mediterranean regions, need thermotolerance to maintain global food security. In this regard, plant scientists are searching for solutions to tackle the yield-declining impacts of HS on crop plants. Glycine betaine (GB) has received considerable attention due to its multiple roles in imparting plant abiotic stress resistance, including to high temperature. Several studies have reported GB as a key osmoprotectant in mediating several plant responses to HS, including growth, protein modifications, photosynthesis, gene expression, and oxidative defense. GB accumulation in plants under HS differs; therefore, engineering genes for GB accumulation in non-accumulating plants is a key strategy for improving HS tolerance. Exogenous application of GB has shown promise for managing HS in plants, suggesting its involvement in protecting plant cells. Even though overexpressing GB in transgenics or exogenously applying it to plants induces tolerance to HS, this phenomenon needs to be unraveled under natural field conditions to design breeding programs and generate highly thermotolerant crops. This review summarizes the current knowledge on GB involvement in plant thermotolerance and discusses knowledge gaps and future research directions for enhancing thermotolerance in economically important crop plants.

Antioxidant status and their enhancements strategies for water stress tolerance in chickpea.

Water stress executes severe influences on the plant growth and development through modifying physio-chemical properties. Therefore, a field experiment was designed to evaluate the antioxidant status and their enhancements strategies for water stress tolerance in chickpea on loam and clay loam soils under agro-ecological conditions of Arid Zone Research Institute, Bahawalpur (29.3871 °N, 71.653 °E) and Cholistan farm near Derawer (28.19°N, 71.80°E) of Southern Punjab, Pakistan during winter 2014-15. Experimental treatments comprised of two chickpea cultivars i.e. Bhakhar 2011 (drought tolerant) and DUSHT (drought sensitive), two water stress levels i.e. water stress at flowering stage and water stress at flowering + pod formation + grain filling stage including well watered (control) and two exogenous application of osmoprotectants i.e. glycine betaine (GB) 20 ppm and proline 10 uM including distilled water (control). Results indicated that water stress at various growth stages adversely affects the growth, yield and quality attributes of both chickpea cultivars. Exogenous application of GB and proline improved the growth, yield and quality parameters of both chickpea cultivars even under water stress conditions. However, superior results were obtained with exogenously applied GB on Bhakhar 2011 under well-watered conditions. Similarly, foliar spray of GB on chickpea cultivar Bhakhar 2011 under stress at flowering + pod formation + grain filling stage produced maximum superoxide dismutase, peroxidase and catalase contents. These results suggested that application of GB mitigates the adverse effects of water stress and enhanced tolerance in chickpea mainly due to higher antioxidant enzymes activity, demonstrating the protective measures of plant cells in stress condition. Hence, antioxidants status might be a suitable method for illustrating water stress tolerance in chickpea.

Exogenous Glycine Betaine Application Improves Freezing Tolerance of Cabbage (Brassica oleracea L.) Leaves.

Exogenous glycine betaine (GB) application has been reported to improve plant tolerance to various abiotic stresses, but its effect on freezing tolerance has not been well studied. We investigated the effect of exogenous GB on freezing tolerance of cabbage (Brassica oleracea L.) leaves. Seedlings fed with 30 mM GB via sub-irrigation showed effectively assimilated GB as evident by higher GB concentration. Exogenous GB did not retard leaf-growth (fresh weight, dry weight, and leaf area) rather slightly promoted it. Temperature controlled freeze-thaw tests proved GB-fed plants were more freeze-tolerant as indicated by lower electrolyte leakage (i.e., indication of less membrane damage) and alleviating oxidative stress (less accumulation of O2•− and H2O2, as well as of malondialdehyde (MDA)) following a relatively moderate or severe freeze-thaw stress, i.e., −2.5 and −3.5 °C. Improved freezing tolerance induced by exogenous GB application may be associated with accumulation of compatible solute (proline) and antioxidant (glutathione). GB-fed leaves also had higher activity of antioxidant enzymes, catalase (CAT), ascorbate peroxidase (APX), and superoxide dismutase (SOD). These changes, together, may improve freezing tolerance through membrane protection from freeze-desiccation and alleviation of freeze-induced oxidative stress.

Effects of exogenous glycine betaine application on some physiological and biochemical properties of cotton (G. hirsutum L.) plants grown in different drought levels

Drought stress significantly reduces the growth and yield of cotton plants; therefore, reducing the damage caused by drought stress and improving the plant growth are highly important. The aims of this study were to investigate some of physiological and biochemical properties of cotton plants exposed to different drought levels and to determine the extent of improvement obtained by exogenous glycine betaine treatment for the damages caused by the adverse effects of drought. Three drought levels were created using PEG (Polyethylene glycol 6000) solution (0%, 10% and 20%). The drought groups were also divided into 2 subgroups by using 0 (control: glycine betaine solution was not applied) and 2 mM glycine betaine solution. The pot experiment was established in a growth chamber with 3 replications and the experiment repeated twice. The changes in the contents of contents of chlorophyll a and b, carotenoid, total dissolved protein, total dissolved carbohydrate and some nutrients were investigated. Chlorophyll a and b, calcium, magnesium, sodium and phosphorus concentrations were decreased, while carotenoid, total dissolved protein and carbohydrate, potassium contents increased with the increasing drought level. The results revealed that adverse effects of drought stress on cotton plants were alleviated by exogenous application of glycine betaine.

Application of exogenous glycinebetaine alleviates lead toxicity in pakchoi (Brassica chinensis L.) by promoting antioxidant enzymes and suppressing Pb accumulation.

Lead (Pb) poses an adverse effect on plant growth and development. Glycinebetaine (GB) plays an important role in plants response to stress environment. The study was performed to examine the potential of exogenous GB (0.5, 1, 2, and 5mM) in alleviating Pb toxicity, the physiological and biochemical responses in pakchoi under 100μM Pb stress by hydroponic experiment. Pb stress significantly decreased the growth, contents of pigment and mineral nutrient, and activities of antioxidative enzymes (CAT, SOD, and APX) in roots and shoots of pakchoi, while it caused a significant increase in Pb and ROS accumulation both in roots and shoots of pakchoi in comparison to the control. Exogenous application of GB improved leaf and root length, fresh and dry weight, mineral nutrient, and pigment contents of pakchoi under Pb stress. GB also effectively enhanced antioxidative enzyme activities and the accumulation of proline, soluble sugar, and GB and reduced the oxidative stress and Pb contents in shoots and roots of pakchoi. Principle component analysis (PCA) provided useful information on the classification of Pb tolerance according to the response to GB. Overall, the 1mMGB was more effective to ameliorate the detrimental impacts of Pb stress. These findings suggested that GB application might be considered an effective strategy for alleviating Pb toxicity and enhancing the tolerance of pakchoi plants under Pb stress.

The role of exogenous glycinebetaine on some antioxidant activity of non-T and T tobacco (Nicotiana tabacum L.) under in vitro salt stress

Glycine betaine is an osmoprotectant compound which enhances cell tolerance in plant species in response to environmental stresses. This study aimed to investigate the effect of exogenous application of glycine betaine on some antioxidant activities of tobacco plants overexpressing P5CS gene. Sterile tobacco seedlings with four to six leaves were transferred to MS medium containing 0, 100, and 200 mM NaCl, after which glycine betaine (20 and 40 mg l-1) were foliar sprayed on the surface of the plants. After four weeks, glycine betaine treatment enhanced the antioxidant capacity of the plant through activation of catalase (CAT), superoxide dismutase (SOD), and ascorbate peroxidase (APX). In contrast, H2O2 content and MDA level were reduced by glycine betaine under similar conditions. Therefore, application of exogenous glycine betaine under salt stress improved stress tolerance in T and non-T plants. Meanwhile, our results indicated the positive effect of glycine betaine in T plants was greater than in non-T plants. On the other hand, this result suggested that the synergistic effects of glycine betaine and proline in plants enhanced the antioxidant defense system in T plants overexpressing P5CS gene.

Incorporated Biochar-Based Soil Amendment and Exogenous Glycine Betaine Foliar Application Ameliorate Rice (Oryza sativa L.) Tolerance and Resilience to Osmotic Stress.

Osmotic stress is a major physiologic dysfunction that alters the water movement across the cell membrane. Soil salinity and water stress are major causal factors of osmotic stress that severely affect agricultural productivity and sustainability. Herein, we suggested and evaluated the impact of integrated biochar-based soil amendment and exogenous glycine betaine application on the growth, physiology, productivity, grain quality, and osmotic stress tolerance of rice (Oryza sativa L., cv. Sakha 105) grown in salt-affected soil under three irrigation intervals (6, 9, or 12 days), as well as soil properties and nutrient uptake under field conditions during the 2019 and 2020 seasons. Our findings showed that dual application of biochar and glycine betaine (biochar + glycine betaine) reduced the soil pH, electrical conductivity, and exchangeable sodium percentage. However, it enhanced the K+ uptake which increased in the leaves of treated-rice plants. Additionally, biochar and glycine betaine supplementation enhanced the photosynthetic pigments (chlorophyll a, b, and carotenoids) and physiological attributes (net photosynthetic rate, stomatal conductance, relative water content, and electrolyte leakage) of osmotic-stressed rice plants. Biochar + glycine betaine altered the activity of antioxidant-related enzymes (catalase, ascorbate peroxide, and peroxidase). Moreover, it improved the yield components, biological yield, and harvest index, as well as the nutrient value of rice grains of osmotic-stressed rice plants. Collectively, these findings underline the potential application of biochar and glycine betaine as a sustainable eco-friendly strategy to improve plant resilience, not only rice, but other plant species in general and other cereal crops in particular, to abiotic stress, particularly those growing in salt-affected soil.

Glycinebetaine: a versatile protectant to improve rice performance against aluminium stress by regulating aluminium uptake and translocation.

Glycinebetaine alleviates the detrimental effects of aluminium stress by regulating aluminium uptake and translocation, maintaining PSII activity, and activating the oxidative defence, thereby maintaining the growth and development of rice. Aluminium (Al) toxicity is one of the primary growth-limiting factors that limits plant growth and crop productivity in acidic soils. Rice (Oryza sativa L.) plants are susceptible to Al stress and do not naturally accumulate glycinebetaine (GB), one of the most effective protectants. Therefore, the objective of this study was to investigate whether exogenous GB can ameliorate the detrimental effects of Al stress on rice plants. Our results showed that the growth, development and biomass of rice were clearly inhibited under Al stress. However, exogenous GB application increased rice shoot growth and photosynthetic pigments contents, maintained photosystem II (PSII) activity, and activated the antioxidant defence system under Al stress. More importantly, GB may mediate the expression of Al uptake- and translocation-related genes, including OsALS1, OsNrat1, OsSTAR1 and OsSTAR2, and the galacturonic acid contents in rice roots under Al stress. Therefore, our findings highlight exogenous GB application is a valid approach to effectively combat Al toxicity by regulating physiological and biochemical processes in crops.

Ex-foliar application of glycine betaine and its impact on protein, carbohydrates and induction of ROS scavenging system during drought stress in flax (Linum usitatissimum)

Crop plants have an innate capacity to acclimatize and survive myriad stresses in field conditions. This acclimatization to stress enhances crop stand in field and productivity of plant. Inter alia field crops withstand drought stress (hydropenia) by inducing synthesis or accumulation of osmolytes such as (i) proline and other amino acids, (ii) glycine betaine (GB), (iii) soluble carbohydrates, and (iv) reactive oxygen species (ROS) scavenging system as intrinsic drought antagonizing molecules. Precise in vivo induction of osmolytes and their effect on ROS scavenging system in flax/linseed has not been elucidated. The investigation was carried out to identify a tolerant and susceptible cultivar of flax from a core collection of 53 core accessions and evaluate the role of compatible osmolytes in Linum usitatissimum under hydropenia. We screened eight morphometrically diverse flax genotypes in field under irrigated and un-irrigated condition and classified them as tolerant and susceptible genotypes. Further, we examined the effect of ex-foliar glycine betaine application - a signature molecule involved in drought tolerance, on selected tolerant and susceptible varieties. Our results showed stimulatory impact of glycine betaine on accumulation of ROS scavenging antioxidants, total soluble protein and on its own accumulation. While the ex-foliar application had no inhibitory effect on the growth of plants; accumulation of free proline, amino acids and carbohydrates are inhibited par se in flax. Our findings reveal, flax is a non-accumulator of glycine betaine and exogenous application of glycine betaine enhances its own levels during drought stress.

Exogenous application of glycine betaine increases the chilling tolerance of pomegranate fruits cv. Malase Saveh during cold storage

Exogenous application of glycine betaine increases the chilling tolerance of pomegranate fruits cv. Malase Saveh during cold storage

Glycinebetaine-Induced Alteration in Gaseous Exchange Capacity and Osmoprotective Phenomena in Safflower (Carthamus tinctorius L.) under Water Deficit Conditions

Several inorganic and organic compounds including glycine betaine (GB) are presently being used as an exogenous application to enhance tolerance in plants to different environmental stresses. The current study assessed to what extent exogenously applied GB could improve the gaseous exchange capacity and primary and secondary metabolites in two accessions (16178 and 16180) of safflower (Carthamus tinctorius L.) plants under drought stress. Three-week-old plants of both safflower accessions were subjected to well-watered (control) or water-deficit conditions (60% field capacity (FC)). Three levels of GB (control, 50 mM and 100 mM) were sprayed to the foliage of the control and stressed plants after one month of drought application. After two weeks of foliar application of GB, gas exchange characteristics and other biochemical parameters were determined. The results showed that water deficiency markedly suppressed plant biomass, chlorophyll contents, photosynthesis rate (A), water use efficiency (A/E), stomatal conductance (gs) and relative water contents (RWC) of both accessions of safflower, while it enhanced the levels of osmolytes (GB and proline), hydrogen peroxide (H2O2) and total phenolics. Foliar application of GB was effective in enhancing the plant biomass, chlorophyll contents, gs, sub-stomatal CO2 concentration (Ci), Ci/Ca ratio, osmolytes, H2O2, ascorbic acid (AsA), total phenolics and RWC in safflower plants under water shortage. Thus, exogenous application of GB could be used as an effective strategy to improve plant growth, photosynthetic attributes and secondary metabolites in safflower plants under water deficit conditions.

Exogenous application of glycine betaine alleviates cadmium toxicity in super black waxy maize by improving photosynthesis, the antioxidant system and glutathione-ascorbic acid cycle metabolites

This study was conducted to examine how glycine betaine (GB) ameliorates the toxic effects of cadmium (Cd) in super black waxy maize. In a Cd toxicity test, biomass accumulation in maize seedlings decreased in comparison with those in the control group (CK). The maize plants exposed to Cd stress exhibited reductions in photosynthetic parameters [net photosynthetic rate (Pn), stomatal conductance (Gs), intracellular CO2 concentration (Ci) and transpiration rate (E)], chlorophyll content and maximum photosynthetic efficiency (Fv/Fm). However, the exogenous application of GB alleviated the negative effects of Cd stress and increased the biomass, photosynthetic parameters (Pn, Gs, Ci, E), chlorophyll content and Fv/Fm of the seedlings. In addition, Cd can decrease the activity of antioxidant enzymes and ascorbic acid (AsA)-glutathione (GSH) cycle enzymes, such as superoxide dismutase, peroxidase, catalase, ascorbate peroxidase, dehydroascorbate reductase, monodehydroascorbate reductase and glutathione reductase, but the activity of these enzymes increased following GB addition. Cd also increased markedly the content of reactive oxygen species and malondialdehyde, but supplementation with GB significantly decreased their content. Furthermore, the levels of AsA and GSH decreased under treatment with Cd, but exogenous GB application increased the content of these compounds. This study shows that GB can alleviate Cd toxicity and provides a theoretical basis for super black maize resistance to heavy metal stress.