Biochemical and Ultrastructural Changes in Wheat Plants during Drought Stress

---

Durna R. Aliyeva^1,a, Ulduza A. Gurbanova^1,b, Fuad H. Rzayev^2,c, Eldar K. Gasimov^3,d, and Irada M. Huseynova^1,4e*

¹Institute of Molecular Biology and Biotechnologies, Ministry of Science and Education of the Republic of Azerbaijan, AZ1073 Baku, Azerbaijan

²Laboratory of Electron Microscopy of the Scientific Research Center of Azerbaijan Medical University, AZ1078 Baku, Azerbaijan

³Department of Histology, Embryology and Cytology, Azerbaijan Medical University, AZ1078 Baku, Azerbaijan

⁴Department of Molecular Biology and Biotechnologies, Baku State University, AZ1148 Baku, Azerbaijan

^* To whom correspondence should be addressed.

Received July 5, 2023; Revised September 4, 2023; Accepted September 22, 2023

---

Drought severely slows down plant growth, decreases crop yield, and affects various physiological processes in plants. We examined four local bread wheat cultivars with different drought tolerance (drought-tolerant Zirva 85 and Murov 2 and drought-sensitive Aran and Gyzyl bughda cultivars). Leaves from seedlings of drought-tolerant plants demonstrated higher activity of antioxidant enzymes and lower levels of malondialdehyde and hydrogen peroxide. The content of soluble proteins in drought-exposed increased, possibly due to the stress-induced activation of gene expression and protein synthesis. Drought-exposed Zirva 85 plants exhibited an elevated activity of nitrogen and carbon metabolism enzymes. Ultrastructural analysis by transmission electron microscopy showed drought-induced damage to mesophyll cells and chloroplast membranes, although it was manifested less in the drought-tolerant cultivars. Comparative analysis of the activity of metabolic and antioxidant enzymes, as well as observed ultrastructural changes in drought-exposed plants revealed that the response to drought of seedlings was more pronounced in drought-tolerant cultivars. These findings can be used in further studies of drought stress in wheat plants under natural conditions.

---

KEY WORDS: wheat, drought, antioxidant enzymes, metabolic enzymes, ultrastructural changes

DOI: 10.1134/S0006297923110226

---