Review

What molecular mechanism is adapted by plants during salt stress tolerance?

Khalid Hussain^1*, M. Farrukh Nisar¹, Abdul Majeed¹, Khalid Nawaz¹, Khizar Hayat Bhatti¹, Shahid Afghan², Aamir Shahazad² and Syed Zia-ul-Hussnian²

¹Department of Botany, University of Gujrat, Gujrat-Pakistan.

²Shakarganj Sugar Research Institute, Jhang-Pakistan.

*Corresponding author. E-mail: khalidbotany@inbox.com.

Accepted 11 December, 2009

   Abstract

Salt stress harmfully shocks agricultural yield throughout the world affecting production whether it is for subsistence or economic outcomes. The plant response to salinity consists of numerous processes that must function in coordination to alleviate both cellular hyperosmolarity and ion disequilibrium. Salt tolerance and yield stability are complex genetic traits that are difficult to establish in crops since salt stress may occur as a catastrophic episode, be imposed continuously or intermittently and become gradually more severe at any stage during development. Molecular biology research has provided new insight into the plant response to salinity and identified genetic determinants that effect salt tolerance. Recent confirmation that many salt tolerance determinants are ubiquitous in plants has led to the use of genetic models, like Arabidopsis thaliana, to further dissect the plant salt stress response. Since many of the most fundamental salt tolerance determinants are those that mediate cellular ion homeostasis, this review will focus primarily on the functional essentiality of ion homeostasis mechanisms in plant salt tolerance. The transport systems that facilitate cellular capacity to utilize Na⁺ for osmotic adjustment and growth and the role of the Salt-Overly-Sensitive (SOS) signal transduction pathway in the regulation of ion homeostasis and salt tolerance will be particularly emphasized. The objective of this review was to identify “What molecular mechanism is adapted by plants during salt stress tolerance?” A conclusion have been presented that integrates cellular based stress signaling and ion homeostasis mechanisms into a functional paradigm for whole plants and defines biotechnology strategies for enhancing salt tolerance of crops.

Key words: Hyper-osmolarity, ion disequilibrium, Arabidopsis thaliana, homeostasis, catastrophic episode.