African Journal of
Biotechnology

  • Abbreviation: Afr. J. Biotechnol.
  • Language: English
  • ISSN: 1684-5315
  • DOI: 10.5897/AJB
  • Start Year: 2002
  • Published Articles: 12496

Full Length Research Paper

Thylakoid-bound ascorbate peroxidase increases resistance to salt stress and drought in Brassica napus

Jian-mei Wang, Zhi-yong Fan, Zhi-bin Liu, Jun-bei Xiang, Liang Chai, Xu-feng Li and Yi Yang*
Key Laboratory of Bio-Resources and Eco-Environment, Ministry of Education, College of Life Science, Sichuan University, Chengdu, Sichuan, P.R. China, 610064
Email: [email protected]

  •  Accepted: 06 June 2011
  •  Published: 03 August 2011

Abstract

Reactive oxygen species (ROS) are cellular indicators of stress. In plants, they function as secondary messengers in response to environmental stress. Ascorbate peroxidase (APX) is an important enzyme directly involved in the scavenging of ROS. In this study, we aimed at identifying the function of the Brassica napusthylakoid APX (tAPX). Germination efficiencies of seeds of B. napus plants over expressing tAPX were higher than those of the seeds of the control plants; this was true both on Murashige and Skoog medium with 300 mM mannitol and with 150 mM NaCl. Further experiments showed that 40-day-old seedlings of the control plants turned yellow, withered, and subsequently died, when treated with 150 mM NaCl for 12 days. In contrast, transgenic plants over expressing tAPX survived this treatment and had at least three green leaves at the end of the experiment. When 40-day-old seedlings were withheld water for 10 days, followed by a 2 day recovery, the control plants exhibited smaller leaves and shorter stems in comparison to tAPX-over expressing plants. In addition, compared with control plants, tAPX-overexpressing plants show reduced hydrogen peroxide accumulation and increased APX relative activity. Our results demonstrate that tAPX plays an important role in resistance to salt stress and drought in plants.

 

Key words: tAPX, transgenic lines, Brassica napus, salt stress, water deficiency.

Abbreviation

ROS, Reactive oxygen species; APX, ascorbate peroxidases;tAPX, thylakoid-bound ascorbate peroxidase; MS, Murashige and Skoog (1962);DAB, 3,3-diaminobenzidine; AsA, ascorbic acid