Salicylic Acid: Physiological Roles in Plants
Since ancient times, salicylic acid has been in use by humans because of its therapeutic properties. Salicylic acid, chemically known as 2-hydroxy benzoic acid is one of a diverse group of phenolic compounds, consisting of an aromatic ring bearing a hydro
- PDF / 1,747,063 Bytes
- 16 Pages / 439.37 x 666.142 pts Page_size
- 98 Downloads / 216 Views
Salicylic Acid: Physiological Roles in Plants Mohammad Yusuf, Shamsul Hayat, Mohammed Nasser Alyemeni, Qazi Fariduddin and Aqil Ahmad
Abstract Since ancient times, salicylic acid has been in use by humans because of its therapeutic properties. Salicylic acid, chemically known as 2-hydroxy benzoic acid is one of a diverse group of phenolic compounds, consisting of an aromatic ring bearing a hydroxyl group or its functional derivative, which is synthesized by plants. Salicylic acid biosynthetic pathway in plants has two distinct pathways, the isochorismate (IC) pathway and the phenylalanine ammonia-lyase (PAL) pathway. Moreover, salicylic acid plays exclusive role in plant growth, thermogenesis, flower induction and uptake of ions. It affects ethylene biosynthesis, stomatal movement and also reverses the effects of ABA on leaf abscission. In addition to this, it also enhances the level of photosynthetic pigments, photosynthetic rate and modifies the activity of some of the important enzymes as well. This chapter provides the reader with a comprehensive coverage to above aspects more exclusively with future prospects. Keywords Growth
Photosynthesis Salicylic acid Senescence Yield
1 Introduction Since ancient times, plants and their extracts have been used for their therapeutic properties. World Health Organization estimated that approximately 75–80 % of the world’s population uses plant medicines either in part or entirely. Ancient M. Yusuf S. Hayat (&) Q. Fariduddin A. Ahmad Plant Physiology Section, Department of Botany, Aligarh Muslim University, Aligarh 202002, India e-mail: [email protected] S. Hayat M. N. Alyemeni Department of Botany and Microbiology, College of Science, King Saud University, Riyadh 11451, Saudi Arabia
S. Hayat et al. (eds.), Salicylic Acid, DOI: 10.1007/978-94-007-6428-6_2, Ó Springer Science+Business Media Dordrecht 2013
15
16
M. Yusuf et al.
Egyptians, for example, chewed willow bark to relieve fever and headaches. Thousands of years later, scientists discovered that the bark contains salicylic acid, the active ingredient used to make aspirin. In the year 1928, John Buchner isolated salicyl alcohol glucoside (Salicine) from willow bark that was later name as Salicylic Acid (hereafter SA) by Rafacle Piria in the year 1938. SA, chemically known as 2-hydroxy benzoic acid is one of a diverse group of phenolic compounds, consisting of an aromatic ring bearing a hydroxyl group or its functional derivative, which is synthesized by plants. Plant phenolics were categorised as secondary metabolites and relatively treated as of low importance in plant metabolism but due to the passage of time this concept changed with the discovery that phenolics play important roles in plant metabolism. For example, phenolics are involved in lignin biosynthesis; others serve as allelopathic compounds, regulate plant responses to abiotic stimuli, or play critical roles in plant disease resistance either by functioning as preformed or inducible antimicrobial defence compounds termed phytoalex
Data Loading...
