Fonksiyonel Tahıllardan Chia’nın (Salvia hispanica L.) Kuraklık Koşullarına Uyum Mekanizmalarının Morfofizyolojik ve Biyokimyasal Açıdan Değerlendirilmesi

Öz

Dünya genelinde kuraklık, tarımsal üretimi sınırlayan en önemli çevresel faktörlerden biri olup ürün verimini ciddi şekilde azaltmaktadır. Bitkiler, bu strese morfolojik, anatomik, fizyolojik, biyokimyasal ve moleküler düzeyde verdikleri yanıtlarla kuraklıkla başa çıkma mekanizmalarını devreye sokmaktadır. Chia (Salvia hispanica L.), içerdiği yüksek düzeyde yağ asidi, protein ve antioksidan bileşenlerle "fonksiyonel gıda" sınıfında yer alan yeni nesil bir tahıldır. Bu çalışmada, kuraklık stresinin chia bitkisinde morfolojik, fizyolojik ve biyokimyasal adaptasyon mekanizmaları üzerindeki etkisi değerlendirilmiştir. Tarla kapasitesine göre %0, %25, %50 ve %100 sulama uygulamaları şeklinde su stresi seviyeleri belirlenmiş ve bitkilerin gelişim özellikleri bu stres seviyelerine göre karşılaştırılmıştır. Morfolojik açıdan, %100 sulama grubunda bitki boyu, yaprak alanı ve taze ağırlık gibi büyümeye yönelik parametrelerde anlamlı artış gözlemlenirken, %50 sulama uygulamasında ana kök uzunluğunun diğer gruplardan bağımsız olarak en yüksek değere ulaştığı tespit edilmiştir. Biyokimyasal bulgular, su eksikliğinin prolin ve malondialdehit (MDA) düzeylerini artırdığını; ayrıca reaktif oksijen türlerini düzenleyen antioksidan enzimlerden süperoksit dismutaz (SOD), katalaz (CAT) ve askorbat peroksidaz (APX) aktivitelerini yükselttiğini göstermiştir. Bu durum, chia bitkisinin hem osmotik hem de oksidatif stresle başa çıkabilmek için çok yönlü savunma mekanizmaları geliştirdiğini ortaya koymaktadır. Su stresinin arttığı %0 ve %25 tarla kapasitesinde, prolin ve MDA birikiminde belirgin artış gözlenmiş; aynı zamanda antioksidatif savunma sistemine ait SOD, CAT ve APX aktiviteleri de yükselmiştir. Korelasyon analizleri, prolin ile antioksidan enzimler arasında pozitif bir ilişki olduğunu ve MDA ile büyüme parametreleri arasında negatif korelasyonlar bulunduğunu göstermiştir. Bu bulgular, sürdürülebilir tarım hedefleri doğrultusunda, kuraklık stresine karşı dayanıklılığı yüksek türlerin, özellikle chia gibi alternatif yağlı tohumlu bitkilerin önemli bir araştırma odağı olması gerektiğini vurgulamaktadır.

Anahtar Kelimeler

• Adaptasyon
• Antioksidan enzimler
• Morfoloji
• Oksidatif hasar
• Salvia hispanica
• Su stresi

Morphophysiological and Biochemical Evaluation of Drought Adaptation Mechanisms in Chia (Salvia hispanica L.) as a Functional Cereal Crop

Öz

Drought is one of the most critical environmental constraints limiting agricultural productivity worldwide and has a significant negative impact on crop yield. Plants respond to drought stress by activating a variety of tolerance mechanisms at the morphological, anatomical, physiological, biochemical, and molecular levels. Chia (Salvia hispanica L.) is a next-generation functional grain, rich in fatty acids, protein, and antioxidant compounds. This study aimed to evaluate the effects of drought stress on the morphophysiological and biochemical adaptation mechanisms in chia plants. Four irrigation levels were established to simulate different levels of water stress: 0%, 25%, 50%, and 100% of field capacity. Growth parameters were compared among these treatments. Morphologically, the 100% irrigation group showed significant increases in plant height, leaf area, and fresh weight. However, the 50% irrigation group exhibited the longest taproot length, indicating a distinct root adaptation strategy under moderate water stress. Biochemical findings showed that water deficit increased proline and malondialdehyde (MDA) levels, as well as the activities of antioxidant enzymes regulating reactive oxygen species, including superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX). This indicates that chia plants develop multifaceted defense mechanisms to cope with both osmotic and oxidative stress. Particularly under 0% and 25% field capacity, proline and MDA accumulation was more pronounced, with significant upregulation of antioxidant enzyme activities. Correlation analysis revealed a positive association between proline and antioxidant enzyme activities, while MDA levels showed a negative correlation with growth parameters. These results emphasize the importance of focusing on drought-resilient crops, especially alternative oilseed species like chia as a key research target in the pursuit of sustainable agricultural practices.

Anahtar Kelimeler

• Adaptation
• Antioxidant enzymes
• Field capacity
• Morphology
• Oxidative damage
• Salvia hispanica L..

Kaynakça

1. Abdollahi, M., Asgarian, M. and Fadaei, R. (2022). Drought-induced oxidative stress in Salvia hispanica (chia): Antioxidant responses and phenolic compounds. Plant Physiology and Biochemistry, 176: 170–178.
2. Ahmar, S., Gill, R. A., Jung, K. H., Faheem, A., Qasim, M. U., Mubeen, M. and Zhou, W. (2023). A decade of omics approaches in cereals: Advanced strategies for crop improvement under changing climate. Frontiers in Plant Science, 14: 1134567.
3. Ali, A. and Alqurainy, F. (2006). Activities of Antioxidants in Plants under Environmental Stress. In: The Lutein-Prevention and Treatment For Age-Related Diseases, Ed(s): Motohashi, N., Transworld Research Network, Trivandrum, India.
4. Apel, K. and Hirt, H. (2004). Reactive oxygen species: Metabolism, oxidative stress, and signal transduction. Annual Review of Plant Biology, 55: 373–399.
5. Ayerza, R. and Coates, W. (2002). Dietary levels of chia: influence on hen weight, egg production and sensory quality, for two strains of hens. British Poultry Science, 43(2): 283–290.
6. Baginsky, C., Arenas, J., Escobar, H., Garrido, M., Valero, N. and von Baer, D. (2016). Growth and yield of chia (Salvia hispanica L.) under different irrigation levels and plant densities in the Mediterranean zone of Chile. Chilean Journal of Agricultural Research, 76(4): 432–437.
7. Balkan, A. (2019). Agronomic performance of seeds of some bread wheat (Triticum aestivum L.) cultivars exposed to drought stress. Journal of Tekirdag Agricultural Faculty, 16(1): 82–91. https://doi.org/10.33462/jotaf.517132.
8. Balkan A. ve Gençtan T. (2013). Ekmeklik buğdayda (Triticum aestivum L.) osmotik stresin çimlenme ve erken fide gelişimi üzerine etkisi. Tekirdağ Ziraat Fakültesi Dergisi, 10: 44–52.

9. Bates, L. S., Waldren, R. P. and Teare, I. D. (1973). Rapid determination of free proline for water-stress studies. Plant and Soil, 39: 205–207.
10. Beauchamp, C. and Fridovich, I. (1971). Superoxide dismutase: Improved assays and an assay applicable to acrylamide gels. Analytical Biochemistry, 44: 276–287.
11. Beers, R. F. and Sizer, I. W. (1952). A spectrophotometric method for measuring the breakdown of hydrogen peroxide by catalase. Journal of Biological Chemistry, 195: 133–140.
12. Bogati, K. and Walczak, M. (2022). The impact of drought stress on soil microbial community, enzyme activities and plants. Agronomy, 12(1): 189.
13. Bushway, A. A., Belya, P. R. and Bushway, R. J. (1981). Chia seed as a source of oil, polysaccharide, and protein. Journal of Food Science, 46: 1349–1356.
14. Bradford, M. M. (1976). A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding. Analytical Biochemistry, 72: 248–254.
15. Chandio, A. A., Jiang, Y., Rehman, A. and Twumasi, M. A. (2021). Climate change and cereal production: Evidence from Pakistan. Environmental Science and Pollution Research, 28(19): 23826–23838.
16. Chen, W. P., Li, P. H. and Chen, T. H. H. (2000). Glycinebetaine increases chilling tolerance and reduces chilling-induced lipid peroxidation in Zea mays L. Plant, Cell and Environment, 23: 609–618.
17. Choukri, A., Cheggour, M., El Khalil, H., Lamtaai, H., Filali-Maltouf, A., El Modafar, C. and Chakhchar, A. (2024). Investigating the morpho-physiological and biochemical traits of chia (Salvia hispanica) to drought stress. New Zealand Journal of Crop and Horticultural Science, 53(2): 349–366.
18. Coates, W. and Ayerza, R. (1996). Production potential of chia North-Western Argentina. Journal of Industrial Crops and Products, 5: 229–233.
19. Comas, L. H., Becker, S. R., Von Mark, V. C., Byrne, P. F. and Dierig, D. A. (2013). Root traits contributing to plant productivity under drought. Frontiers in Plant Science, 4: 442.
20. Du, F., Shi, H., Zhang, X. and Xu, X. (2014). Responses of reactive oxygen scavenging enzymes, proline and malondialdehyde to water deficits among six secondary successional seral species in Loess Plateau. PLoS One, 9(6): e98872.
21. European Commission (2017). Commission Implementing Regulation (EU) 2017/2470 of 20 December 2017 establishing the Union list of novel foods. Official Journal of the European Union, L351, 72–201. https://eur-lex.europa.eu/eli/reg_impl/2017/2470/oj
22. Farooq, M., Wahid, A., Kobayashi, N., Fujita, D. and Basra, S. M. A. (2009). Plant drought stress: effects, mechanisms and management. Agronomy for Sustainable Development, 29(1): 185–212.
23. Fujita, M., Fujita, Y., Noutoshi, Y., Takahashi, F., Narusaka, Y., Yamaguchi-Shinozaki, K. and Shinozaki, K. (2006). Crosstalk between abiotic and biotic stress responses: A current view from the point of convergence in the stress signaling networks. Current Opinion in Plant Biology, 9(4): 436–442.
24. Geneve, R. L., Hildebrand, D. F., Phillips, T. D., Al-Amery, M. and Kester, S. T. (2017). Stress influences seed germination in mucilage‐producing chia. Crop Science, 57: 2160–2169.
25. Hayat, S., Hayat, Q., Alyemeni, M. N., Wani, A. S., Pichtel, J. and Ahmad, A. (2012). Role of proline under changing environments: a review. Plant Signaling & Behavior, 7(11): 1456–1466.
26. Ixtaina, Y., Nolasco, S. M. and Tomas, M. C. (2008). Physical properties of chia (Salvia hispanica L.) seeds. Industrial Crops and Products, 28: 286–293.
27. Kato, M. and Shimizu, S. (1987). Chlorophyll metabolism in higher plants. VII. Chlorophyll degradation in senescing tobacco leaves; phenolic-dependent peroxidative degradation. Canadian Journal of Botany, 65: 729–735.
28. Mallikarjuna, B. P., Sreevathsa, R. and Varshney, R. K. (2022). Genomics-assisted breeding for climate-resilient crops: Progress and prospects. Theoretical and Applied Genetics, 135(3): 751–776.
29. McClelland, S. C., Bossio, D., Gordon, D. R., Lehmann, J., Hayek, M. N., Ogle, S. M., Sanderman, J., Wood, S. A., Yang, Y., and Woolf, D. (2025). Managing for climate and production goals on crop-lands. Nature Climate Change, 15(6): 642–649.
30. Mittler, R. (2002). Oxidative stress, antioxidants and stress tolerance. Trends in Plant Science, 7(9): 405–410. Morales, M. and Munné-Bosch, S. (2019). Malondialdehyde: Facts and artifacts. Plant Physiology, 180: 1246–1250.
31. Muñoz, L. A., Cobos, A., Diaz, O. and Aguilera, J. M. (2013). Chia seed (Salvia hispanica): An ancient grain and a new functional food. Food Reviews International, 29(4): 394–408.
32. Sandoval-Oliveros, M. R. and Paredes-López, O. (2013). Isolation and characterization of proteins from chia seeds (Salvia hispanica L.). Journal of Agricultural and Food Chemistry, 61(1): 193–201.
33. Shao, H. B., Chu, L. Y., Wu, G., Zhang, J. H., Lu, Z. H. and Hu, Y. C. (2007). Changes of some anti-oxidative physiological indices under soil water deficits among 10 wheat (Triticum aestivum L.) genotypes at tillering stage. Colloids and Surfaces B: Biointerfaces, 54: 143–149.
34. Silva, H., Arriagada, C., Campos-Saez, S., Baginsky, C., Castellaro-Galdames, G. and Morales-Salinas, L. (2018). Effect of sowing date and water availability on growth of plants of chia (Salvia hispanica L.) established in Chile. PLoS One, 13(9): e0203116.
35. Szabados, L. and Savouré, A. (2010). Proline: A multifunctional amino acid. Trends in Plant Science, 15(2): 89–97.
36. Taga, M. S., Miller, E. E. and Pratt, D. E. (1984). Chia seeds as a source of natural lipid antioxidants. Journal of the American Oil Chemists’ Society, 61: 928–931.
37. Taniushkina, A. A., Ivanov, P. P. and Dmitriev, A. A. (2024). Harnessing plant biotechnology for food security under climate change. Biotechnology Advances, 64: 108180.
38. Tyree, M. T. and Zimmermann, M. H. (2002). Xylem Structure and the Ascent of Sap. Springer Science & Business Media, New York, U.S.A.
39. Verma, S., Rastogi, M., Anjali Mishra, J. and Verma, S. (2022). A Textbook of Stress Crop Production. B P International, West Bengal.
40. Vishnoi, R. and Goel, A. (2024). Climate-smart agriculture and the role of cereal crops in global food systems. Agricultural Systems, 211: 103767.
41. Xiong, L., Schumaker, K. S. ve Zhu, J. K. (2002). Cell signaling during cold, drought, and salt stress. The Plant Cell, 14(3): 165–183.
42. Yancey, P. H. (2005). Osmotic regulation in the deep-sea: Origins of osmotic pressure in deep-sea organisms. Marine Ecology Progress Series, 295: 171–185.
43. Yang, X., Lu, M., Wang, Y., Wang, Y., Liu, Z. and Chen, S. (2021). Response mechanism of plants to drought stress. Horticulturae, 7(3): 50.
44. Zhu, J. K. (2016). Abiotic stress signaling and responses in plants. Cell, 167(2): 313–324.