The role of chitosan priming in induction of GABA shunt pathway during wheat (Triticum durum L.) Seed germination under salt stress

Title : The role of chitosan priming in induction of GABA shunt pathway during wheat (Triticum durum L.) Seed germination under salt stress

Abstract:

Soil salinity leads to a reduction in plant growth, germination, relative water content, and reduces production of wheat plants worldwide. Chitosan showed a positive effect on plant growth, development and improve plant stress tolerance. The current study aimed to examine the effect of different chitosan concentrations on gamma-aminobutyric acid (GABA) shunt pathway in germinating seeds of wheat (Triticum durum L.) under salt stress through the characterization of seed germination pattern, seed moisture content, GABA shunt metabolite level (GABA, glutamate and alanine), the level of oxidative damage in term of measuring malondialdehyde (MDA) accumulation level and the GAD mRNA transcription level in response NaCl treatments. Pre-treatment of wheat seeds with chitosan improved germination by enhancing germination percentage, seedling length, seedling fresh and dry weights, especially under salt stress. Data showed an increase in GABA shunt and their metabolites (alanine and glutamate), MDA content and mRNA transcription level, and a decrease in germination percentage, seedling length, seedling fresh and dry weights for both untreated and chitosan treated seeds under salt stress. Our results suggest that the elevation of GABA level in chitosan-treated seeds was to maintain the metabolic stability under salt stress. In addition, MDA content increased in chitosan-treated seeds as NaCl concentration increased. However, the increase was slightly lower than the MDA level in untreated seeds which confirmed that chitosan activates GAD mRNA expression that leads to activate GABA shunt which is involved in the reduction of membrane damage and activation of reactive oxygen species scavenging systems under salt stress. Consequently, this study demonstrated that chitosan significantly enhanced the accumulation of GABA and amino acids metabolism to maintain the C:N metabolic balance and improved salt tolerance in wheat seeds during seed germination.

Biography:

Nisreen AL-Quraan graduated in 1998 with Bachelor of Science degree from theDepartment of Biological Sciences, Yarmouk University, Jordan. She joined the graduate program in the Department of Biological sciences, Yarmouk University and received her Master of Science degree in Plant Biochemistry and Molecular biology in 2001. After completion of her MS, she worked as research and teaching assistant for two years in the Department of Biological Sciences, Yarmouk University, Jordan. On May, 2004 she joined the Department of Biological Sciences, Auburn University, Alabama, USA to pursue her PhD degree in Plant Biochemistry and Molecular Biology working on the plant abiotic stress interaction and the role of GABA shunt pathway in plant stress tolerance. She obtained her PhD Degree in August, 2008 from Auburn University, Alabama, USA. Since September 2008, Nisreen AL-Quraan has been working as a professor in plant biochemistry and molecular biology at Jordan University of Science and Technology, JORDAN. Her research is focusing on investigating the pathways that enable plants to adapt and tolerate harsh biotic and Abiotic stress conditions. She is interested in understanding the role of GABA shunt metabolic pathway that is activated in response to the interactions between plants and its environments.