The Antioxidant Defense System of Tomato (Solanum lycopersicum L.) Varieties under Drought Stress and upon Post-Drought Rewatering

---

Naima N. Niyazova^1,a, Irada M. Huseynova^1,2,b*

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

²Department of Molecular Biology and Biotechnologies, Baku State University, Baku, AZ1148, Azerbaijan

^* To whom correspondence should be addressed.

Received: April 5, 2024; Revised: April 16, 2024; Accepted: April 16, 2024

---

Water shortage induces physiological, biochemical, and molecular alterations in plant leaves that play an essential role in plant adaptive response. The effects of drought and post-drought rewatering on the activity of antioxidant enzymes and levels of H₂O₂, phenolic compounds, ascorbic acid, and proline were studied in six local tomato (Solanum lycopersicum L.) varieties. The contents of H₂O₂ and ascorbic acid increased in all drought-exposed tomato plants and then decreased upon rewatering. The level of phenolic compounds also decreased in response to water shortage and then recovered upon rehydration, although the extent of this response was different in different varieties. The activities of ascorbate peroxidase (APX) and guaiacol peroxidase (POX) and the content of proline significantly increased in the drought-stressed plants and then decreased when the plants were rewatered. The activities of 8 constitutive APX isoforms and 2 constitutive POX isoforms varied upon exposure to drought and were observed after rewatering in all studied varieties. The information on the response of tomato plants to drought and subsequent rewatering is of great importance for screening and selection of drought-tolerant varieties, as well as for development of strategies for increasing plant productivity under adverse environmental conditions.

---

KEY WORDS: Solanum lycopersicum L., ascorbate peroxidase, guaiacol peroxidase, ascorbic acid, proline, phenolic compounds, drought, rewatering

DOI: 10.1134/S0006297924060130

Publisher’s Note. Pleiades Publishing remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

---