Mohammad Anwar Hossain^1,2 , Mohammad Golam Mostofa^1,3 , Masayuki Fujita¹

1 Laboratory of Plant Stress Responses, Department of Applied Biological Science, Faculty of Agriculture, Kagawa University, Miki-cho, Kita-gun, Kagawa 761-0795, Japan
2 Department of Genetics and Plant Breeding, Bangladesh Agricultural University, Mymensingh- 2202, Bangladesh
3 Department of Biochemistry, Bangabandhu Sheikh Mujibur Rahman Agricultural University, Gazipur-1706, Bangladesh
Author    Correspondence author
Molecular Plant Breeding, 2013, Vol. 4, No. 7   doi: 10.5376/mpb.2013.04.0007
Received: 16 Jan., 2013    Accepted: 22 Jan., 2013    Published: 07 Feb., 2013

This is an open access article published under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Mohammad et al., 2013, Cross Protection by Cold-shock to Salinity and Drought Stress-induced Oxidative Stress in Mustard (Brassica campestris L.) Seedlings, Molecular Plant Breeding, Vol.4, No.7 50-70 (doi: 10.5376/mpb.2013.04.0007)

In the present study, cold-shock (6℃, 5.5 h) induced salinity and drought tolerance and involvement of antioxidative and glyoxalase systems were investigated in mustard (Brassica campestris L.) seedlings. Seven-day-old seedlings were subjected to salt (150 mmol/L NaCl, 48 h) and drought stress (induced by 20% PEG, 48 h) with or without cold pre-treatment. The results showed that both salt and drought stresses abruptly increased the hydrogen peroxide (H₂O₂) and lipid peroxidation (malondialdehyde, MDA) levels. Ascorbate (AsA), reduced glutathione (GSH) and oxidized glutathione (GSSG) contents, GSH/GSSG ratio and the activities of ascorbate peroxidase (APX), monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR), glutathione reductase (GR), glutathione S-transferase (GST), glutathione peroxidase (GPX), catalase (CAT), glyoxalase I (Gly I), and glyoxalase II (Gly II) showed both homogeneity and discrepancies in the responses of mustard seedlings to salinity and drought stresses. Drought stress treatment resulted in a significant increases in AsA content. The GSH and GSSG content increased in response to both salt and drought stresses, however, the GSH/GSSG ratio decreased significantly in response to drought stress. Salt stress treatment resulted in a significant increase of APX, MDHAR, GR, GST and Gly I activities, whereas, CAT and Gly II activities decreased. In contrast, drought stress treatment resulted in a significant increase in MDHAR, DHAR, GPX and Gly I activities; whereas, APX, CAT and Gly II activities decreased. Importantly, cold pre-treated salt and drought-stressed seedlings maintained higher level of AsA, GSH contents and GSH/GSSG ratio, higher activities of APX, DHAR, GR, GST, GPX, CAT, Gly I and Gly II, and lower the levels of GSSG, H₂O₂ and MDA as compared to the control as well as in most cases seedlings subjected to salt and drought stress without cold pre-treatment. Our findings showed that a retention of the imprint of previous stress exposure (short-term cold-shock), induces salt and drought-induced oxidative stress tolerance by modulating antioxidative and glyoxalase systems.

Cross-adaptation; Cold-shock; Salt and drought stress; Antioxidative and glyoxalase system; Brassica campestris L.