Abstract
Abstract Increasing salinity in irrigation water and soil represents a crucial problem against plant growth and development especially the agricultural crops. A number of plants own the ability to adapt to salt by recruiting a set of genes that are expressed and regulated under salt stress conditions. Using the model plant; Arabidopsis in studying gene function and regulation has a great importance in plant biotechnology. This research mainly aims to estimate the level of salt stress resistance of Arabidopsis plants by measuring plant canopy temperature. After adaptation to salt stress, Columbia 0 ‘wild type’ and sus1 mutant of the gene sucrose synthase ‘SUS1’ plants were grown to the appropriate stage and then treated with NaCl solution at 0.0, 100 & 200 mM. Plant canopy temperature, plant morphological changes, plant survival, and leave chlorophyll content were estimated. The results showed that there were no significant differences between the wild type and the mutant in plant temperature and plant survival. The morphology of sus1 mutant plants was severely affected by salinity at 100 mM NaCl after 7 days comparing to wild type which may indicate a function of the SUS1 gene in salt stress response. Leave content of chlorophyll a, b, and total chlorophyll was significantly increased in both Columbia 0 and sus1 plants when treated with 200 mM NaCl comparing to 0.0 and 100 mM but Columbia 0 plants preserved higher amount of chlorophyll comparing to sus1. Having found a less amount of chlorophyll in leaves in the mutant might be refereed to presences of a T-DNA within the SUS1 gene sequence which knocked out the gene, and thus may indicate a role of SUS1 gene in chlorophyll synthesis. More investigations are needed to confirm the possible leaf structural changes that allow plants to preserve more chlorophyll under higher salt levels and also, the possible function of the SUS1 gene in chlorophyll synthesis. Keywords: T-DNA, salt stress, thermal imaging, chlorophyll, Arabidopsis