Tebuconazole and trifloxystrobin regulate the physiology, antioxidant defense and methylglyoxal detoxification systems in conferring salt stress tolerance in Triticum aestivum L

Sayed Mohammad Mohsin; Mirza Hasanuzzaman; Kamrun Nahar; Md Shahadat Hossain; M H M Borhannuddin Bhuyan; Khursheda Parvin; Masayuki Fujita

doi:10.1007/s12298-020-00810-5

Tebuconazole and trifloxystrobin regulate the physiology, antioxidant defense and methylglyoxal detoxification systems in conferring salt stress tolerance in Triticum aestivum L

Physiol Mol Biol Plants. 2020 Jun;26(6):1139-1154. doi: 10.1007/s12298-020-00810-5. Epub 2020 May 15.

Authors

Sayed Mohammad Mohsin^{1

2}, Mirza Hasanuzzaman³, Kamrun Nahar⁴, Md Shahadat Hossain¹, M H M Borhannuddin Bhuyan^{1

5}, Khursheda Parvin^{1

6}, Masayuki Fujita¹

Affiliations

¹ Laboratory of Plant Stress Responses, Department of Applied Biological Sciences, Faculty of Agriculture, Kagawa University, Miki-Cho, Kita-Gun, Kagawa 761-0795 Japan.
² Department of Plant Pathology, Faculty of Agriculture, Sher-e-Bangla Agricultural University, Sher-e-Bangla Nagar, Dhaka, 1207 Bangladesh.
³ Department of Agronomy, Faculty of Agriculture, Sher-e-Bangla Agricultural University, Sher-e-Bangla Nagar, Dhaka, 1207 Bangladesh.
⁴ Department of Agricultural Botany, Faculty of Agriculture, Sher-e-Bangla Agricultural University, Sher-e-Bangla Nagar, Dhaka, 1207 Bangladesh.
⁵ Bangladesh Agricultural Research Institute, Citrus Research Station, Jaintapur, Sylhet, 3156 Bangladesh.
⁶ Department of Horticulture, Faculty of Agriculture, Sher-e-Bangla Agricultural University, Sher-e-Bangla Nagar, Dhaka, 1207 Bangladesh.

Abstract

Fungicides are widely used for controlling fungi in crop plants. However, their roles in conferring abiotic stress tolerance are still elusive. In this study, the effect of tebuconazole (TEB) and trifloxystrobin (TRI) on wheat seedlings (Triticum aestivum L. cv. Norin 61) was investigated under salt stress. Seedlings were pre-treated for 48 h with fungicide (1.375 µM TEB + 0.5 µM TRI) and then subjected to salt stress (250 mM NaCl) for 5 days. Salt treatment alone resulted in oxidative damage and increased lipid peroxidation as evident by higher malondialdehyde (MDA) and hydrogen peroxide (H₂O₂) content. Salt stress also decreased the chlorophyll and relative water content and increased the proline (Pro) content. Furthermore, salt stress increased the dehydroascorbate (DHA) and glutathione disulfide (GSSG) content while ascorbate (AsA), the AsA/DHA ratio, reduced glutathione (GSH) and the GSH/GSSG ratio decreased. However, a combined application of TEB and TRI significantly alleviated growth inhibition, photosynthetic pigments and leaf water status improved under salt stress. Application of TEB and TRI also decreased MDA, electrolyte leakage, and H₂O₂ content by modulating the contents of AsA and GSH, and enzymatic antioxidant activities. In addition, TEB and TRI regulated K⁺/Na⁺ homeostasis by improving the K⁺/Na⁺ ratio under salt stress. These results suggested that exogenous application of TEB and TRI rendered the wheat seedling more tolerant to salinity stress by controlling ROS and methylglyoxal (MG) production through the regulation of the antioxidant defense and MG detoxification systems.

Keywords: Antioxidant defense; Fungicides; Glyoxalase system; Reactive oxygen species; Salt stress.