Effect of Iron stress on Selected Physiological and Spectral parameter on four Rice varieties (Oryza sativa L.)

Iron toxicity is an abiotic stress coming with high concentrations of Fe2+ in the soil solution which is a wellrecognized problem of rice (Oryza sativa L.) cultivation in lowland. Rice varieties differ widely in their ability to tolerate excess iron. The present study was undertaken with four rice varieties viz. Dhruba, Sampriti, Dhiren, and Puspa. The objective is to study the influence of high applied Fe2+ concentrations on the growth, chlorophyll content, and antioxidant enzyme activities. The spectral reflectivity and absorption of different chemical bonding through Fourier transform infrared spectroscopy (FTIR) of four rice varieties was also analyzed. Seven-day-old rice seedlings treated with Ferrous sulphate and subjected to 100 ppm to 750 ppm for further 14-day iron stress were used to analyze their morphological and biochemical responses. Besides, Fourier transform infrared spectral reflection was attributed in root and shoot part. Results indicated shoot growth and chlorophyll content decreased in 750 ppm in all the selected rice varieties of interest. On the contrary, the catalase activity, protein content, and lipid peroxidation increased in these varieties. However, the expression of high amount of CAT activity in Sampriti variety and high amount of SOD activity in Dhruba variety led to tolerance in iron stress in comparison to other two varieties of interest. FTIR revealed steep band stretching of various functional groups of different compounds in both the root and shoot parts of all the varieties. Results revealed that the change of antioxidant expression and FTIR spectra were attributed to the effect of iron toxicity on rice plants.