Modulating γ-aminobutyric acid content across the vegetative and generative stages of black glutinous rice (Oryza sativa L.) via drought stress

Abstract

γ-aminobutyric acid (GABA) is a non-protein amino acid naturally present in rice with health benefits. GABA is synthesized through glutamate decarboxylation, facilitated by glutamate decarboxylase, due to drought stress in the environment. This study assesses the effects of drought stress on GABA content in black glutinous rice during vegetative and generative stages, followed by an investigation of rewatering effects at each growth stage. Drought stress was simulated in vivo using PEG-6000 concentrations of 0% and 10%, applied at vegetative and generative stages. In the generative phase, providing 10% PEG-6000 increased GABA content, H₂O₂, and MDA levels, while also causing photosynthetic disruption and chlorophyll reduction. In contrast, due to the rewatering process, GABA production decreased, along with upregulation of GABA-T gene expression during both vegetative and generative stages. These findings suggest that increased GABA production may contribute to tolerance to PEG-induced osmotic stress in black glutinous rice, based on metabolic adjustment, gene expression, and antioxidant activity. Increased GABA accumulation was associated with enhanced physiological and biochemical response to PEG-induced osmotic stress, suggesting that GABA metabolism may contribute to the adaptive response of black glutinous rice under osmotic stress.

Keywords

GABA / drought stress / black Glutinous rice / gene expression / photosynthetic system

References

[1] Qodir A, Suhartanto MR, Widajati E, et al (2024) Commercial rice seed production and distribution in Indonesia. Heliyon 10: e25110. http://doi.org/10.1016/j.heliyon.2024.e25110

[2] Rozi F, Santoso AB, Mahendri IGAP, et al. (2023) Indonesian market demand patterns for food commodity sources of carbohydrates in facing the global food crisis. Heliyon 9: e16809. https://doi.org/10.1016/j.heliyon.2023.e16809

[3] Abebaw SE (2025) A global review of the impacts of climate change and variability on agricultural productivity and farmers’ adaptation strategies. Food Sci Nutr 13: e70260. https://doi.org/10.1002/fsn3.70260.

[4] Guo H, Wang R, Gregg M, et al. (2021) Rice drought risk assessment under climate change: Based on physical vulnerability a quantitative assessment method. Sci Total Environ 751: 141481. https://doi.org/10.1016/j.scitotenv.2020.141481

[5] Velazquez-Chavez LJ, Daccache A, Mohamed AZ, et al. (2024) Plant-based and remote sensing for water status monitoring of orchard crops: Systematic review and meta-analysis. Agr Water Manage 303: 109051 https://doi.org/10.1016/j.agwat.2024.109051.

[6] Panda SK, Gupta D, Patel M, et al. (2024) Functionality of reactive oxygen species (ROS) in plants: toxicity and control in poaceae crops exposed to abiotic stress. Plants 13: 2071. https://doi.org/10.3390/plants13152071

[7] Seleiman MF, Al-Suhaibani N, Ali N, et al. (2021) Drought stress impacts on plants and different approaches to alleviate its adverse effects. Plants 10: 259. http://doi.org/10.3390/plants10020259.

[8] Chen M, Zhu C, Zhang H, et al. (2024) Endogenous γ-Aminobutyric acid accumulation enhances salinity tolerance in rice. Plants 13: 2750. https://doi.org/10.3390/plants13192750

[9] Zhu L, Wang Z, Gao L, et al. (2024) Unraveling the potential of γ-aminobutyric acid: Insights into its biosynthesis and biotechnological applications. Nutrients 16: 2760. https://doi.org/10.3390/nu16162760.

[10] Zhu F, Hu S, Zhao W, et al. (2023) A novel method for γ-aminobutyric acid biosynthesis using glutamate decarboxylase entrapped in polyvinyl alcohol-sodium alginate capsules. Molecules 28: 6844. https://doi.org/10.3390/molecules28196844

[11] Marilovtseva EV, Abdurazakov A, Kurishev AO, et al. (2025) The role of GABA pathway components in pathogenesis of neurodevelopmental disorders. Int J Mol Sci 26: 9492. https://doi.org/10.3390/ijms26199492

[12] Dewan F, Ahiduzzaman, Islam N, et al. (2023) Potential benefits of bioactive compounds of traditional rice grown in South and Southeast Asia: A review. Rice Sci 30: 537-551. https://doi.org/10.1016/j.rsci.2023.07.002.

[13] García-Castro A, Román-Gutiérrez AD, Castañeda-Ovando A, et al. (2022) Cereals as a source of bioactive compounds with anti-hypertensive activity and their intake in times of COVID-19. Foods 11: 3231. https://doi.org/10.3390/foods11203231

[14] Mbanjo EGN, Kretzschmar T, Jones H, et al. (2020) The genetic basis and nutritional benefits of pigmented rice grain. Front Genet 11: 229. https://doi.org/10.3389/fgene.2020.00229

[15] Jaksomsak P, Rerkasem B, Prom-U-Thai C (2021) Variation in nutritional quality of pigmented rice varieties under different water regimes. Plant Prod Sci 24: 244-255. https://doi.org/10.1080/1343943X.2020.1819164

[16] Pradipta S, Ubaidillah M, Siswoyo TA (2020) Physicochemical, functional and antioxidant properties of pigmented rice. Curr Res Nutr Food S 8: 837-851. http://dx.doi.org/10.12944/CRNFSJ.8.3.15

[17] Kang SJ, Jeong SY, Islam MZ, et al. (2022) Bioactive compounds and quality evaluation of red-pigmented rice processed by germination and roasting. Foods 11: 2735. https://doi.org/10.3390/foods11182735.

[18] Siswoyo TA, Arum LS, Sanjaya BRF, et al. (2021) The growth responses and antioxidant capabilities of melinjo (Gnetum gnemon L.) in different durations of drought stress. Ann Agr Sci 66: 81-86. https://doi.org/10.1016/j.aoas.2021.05.003

[19] Nio SA, Ludong DPM, Acuna TLB, et al. (2024). Solute contributions to osmotic adjustment in leaf segments of wheat (Triticum aestivum L.) exposed to polyethylene glycol-induced water deficit. Plant Prod Sci 27: 99-109. https://doi.org/10.1080/1343943X.2023.2299644

[20] Islam MM, Kayesh E, Zaman E, et al. (2018) Evaluation of rice (Oryza sativa L.) genotypes for drought tolerance at germination and early seedling stage. Agriculturists 16: 44-54.

[21] Pharmawati M, Wirasiti NN, Wrasiati LP (2018) Respon morfologis dan ekspresi gen aquaporin pada padi ir 64 yang mengalami cekaman kekeringan pada fase reproduktif. Bioslogos 7: 60-66. https://doi.org/10.35799/jbl.7.2.2017.18579

[22] Lichtenthaler HK, Babani F (2022) Contents of photosynthetic pigments and ratios of chlorophyll a/b and chlorophylls to carotenoids (a+b)/(x+c) in C4 plants as compared to C3 plants. Photosynthetica 60: 3-9. https://doi.org/10.32615/ps.2021.041

[23] Karladee D, Suriyong S (2012) -Aminobutyric acid (GABA) content in different varieties of brown rice during germination. Sci Asia 38: 13-17. https://doi.org/10.2306/scienceasia1513-1874.2012.38.013

[24] Jira-anunkul W, Pattanagul W (2020) Seed priming with hydrogen peroxide alleviates the effects of drought stress in rice (Oryza sativa L.) seedlings. Not Bot Horti Agrobo 48: 273-283. https://doi.org/10.15835/nbha48111829

[25] Miftahudin, Rury EP, Tatik C (2020) Vegetative morphophysiological responses of four rice cultivars to drought stress. Biodiversitas 21: 3727-3734. https://doi.org10.13057/biodiv/d210840

[26] Noviyanti E, Supriyadi A, Sekar Arum, et al. (2020) Effect of germination on free radical scavenging activities and angiotensin I-converting enzyme inhibitory of melinjo (Gnetum gnemon L) seed proteins. J Microb Biotec Food 9: 809-812. https://doi.org/10.15414/jmbfs.2020.9.4.809-812

[27] Bradford MM (1976) A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding. Anal Biochem 72: 248-254. https://doi.org/10.1016/0003-2697(76)90527-3

[28] Re R, Pellegrini N, Proteggente A, et al. (1999) Antioxidant activity applying an improved ABTS radical cation decolorization assay. Free Radical Bio Med 26: 1231-1237. https://doi.org/10.1016/S0891-5849(98)00315-3

[29] Siswoyo TA, Ardyati T, Hosokawa K (2017) Fermentation-induced changes in antioxidant activities and oxidative DNA damage protection of melinjo (Gnetum gnemon) flour. J Food Biochem 41: e12382. https://doi.org/10.1111/jfbc.12382

[30] Kim DW, Shibato J, Agrawal GK, et al. (2007) Gene transcription in the leaves of rice undergoing salt-induced morphological changes (Oryza sativa L.). Mol Cells 24: 45-59. https://doi.org/10.1016/S1016-8478(23)10755-2

[31] Farooq M, Kobayashi N, Wahid A, et al. (2009) Strategies for producing more rice with less water. Adv Agron 101: 351-388. https://doi.org/10.1016/S0065-2113(08)00806-7

[32] Yang X, Lu M, Wang Y, et al. (2021) Response mechanism of plants to drought stress. Horticulturae 7: 50. https://doi.org/10.3390/horticulturae7030050

[33] Bian F, Wang Y, Duan B, et al. (2021) Drought stress introduces growth, physiological traits and ecological stoichiometry changes in two contrasting Cunninghamia lanceolata cultivars planted in continuous-plantation soils. BMC Plant Biol 21: 379. https://doi.org/10.1186/s12870-021-03159-3

[34] Yan W, Lu Y, Guo L, et al. (2024) Effects of drought stress on photosynthesis and chlorophyll fluorescence in blue honeysuckle. Plants 13: 2115. https://doi.org/10.3390/plants13152115.

[35] Zhang RR, Wang YH, Li T, et al. (2021) Effects of simulated drought stress on carotenoid contents and expression of related genes in carrot taproots. Protoplasma 258: 379-390. https://doi.org/10.1007/s00709-020-01570-5

[36] Qiao M, Hong C, Jiao Y, et al. (2024) Impacts of drought on photosynthesis in major food crops and the related mechanisms of plant responses to drought. Plants 13: 1808. https://doi.org/10.3390/plants13131808

[37] Du Y, Zhao Q, Chen L, et al. (2020) Effect of drought stress at reproductive stages on growth and nitrogen metabolism in soybean. Agronomy 10: 1-21. https://doi.org/10.3390/agronomy10020302

[38] Lin Y, Xu H, Yin G, et al. (2022) Dynamic changes in membrane lipid metabolism and antioxidant defense during Soybean (Glycine max L. Merr.) seed aging. Front Plant Sci 13: 908949. http://doi.org/10.3389/fpls.2022.908949

[39] Wang L, Zhang X, She Y, et al. (2022) Physiological adaptation mechanisms to drought and rewatering in water-saving and drought-resistant rice. Int J Mol Sci 23: 14043. https://doi.org/10.3390/ijms232214043

[40] Wu H, Yang Z (2024) Effects of drought stress and postdrought rewatering on winter wheat: A meta-analysis. Agronomy 14: 298. https://doi.org/10.3390/agronomy14020298

[41] Kinnersley AM, Turano FJ (2000) Gamma aminobutyric acid (GABA) and plant responses to stress. Crit Rev Plant Sci 19: 479-509. https://doi.org/10.1080/07352680091139277

[42] Michaeli S, Fromm H (2015) Closing the loop on the GABA shunt in plants: Are GABA metabolism and signaling entwined? Front Plant Sci 6: 419. https://doi.org/10.3389/fpls.2015.00419

[43] Podlešáková K, Ugena L, Spíchal L, et al. (2019) Phytohormones and polyamines regulate plant stress responses by altering GABA pathway. New Biotech 48: 53-65. https://doi.org/10.1016/j.nbt.2018.07.003

[44] Yuan D, Wu X, Gong B, et al. (2023) GABA metabolism, transport and their roles and mechanisms in the regulation of abiotic stress (hypoxia, salt, drought) resistance in plants. Metabolites 13: 347. https://doi.org/10.3390/metabo13030347

[45] Palabıyık Ş, Çetinkaya İ, Öztürk T, et al. (2025) GABA in plant stress response and tolerance mechanisms, GABA in Plants, Wiley. https://doi.org/10.1002/9781394217786.ch9

[46] Raza A, Razzaq A, Mehmood SS, et al. (2019) Impact of climate change on crops adaptation and strategies to tackle its outcome: A Review. Plants 8: 34. https://doi.org/10.3390/plants8020034

[47] Zhang F, Rosental L, Ji B, et al. (2024) Metabolite-mediated adaptation of crops to drought and the acquisition of tolerance. Plant J 118: 626-644. https://doi.org/10.1111/tpj.16634