Response of regulation of resistance genes, reactive oxygen species, and antioxidant enzymes to salicylic acid treatments in drought tolerant rice

M. Ubaidillah¹², F. Oktaviani², M.A. Mufadilah¹, S. Avivi¹, N. Thamrin¹, A. Indrawati¹, A.N. Puspito², K.M. Kim³ and S. Hartatik¹*

¹1University of Jember, Faculty of Agriculture, Study Program of Agronomy,
Jember Regency, East Java 6812, Indonesia
²University of Jember, Faculty of Agriculture, Study Program of Magister Biotechnology, Jember Regency, East Java 6812, Indonesia
³Division of Plant Biosciences, School of Applied BioSciences, College of Agriculture and Life Science, Kyungpook National University, Daegu, South Korea
*Correspondence: srihartatik.faperta@unej.ac.id

Abstract:

Drought is one of the most important issues in crop production which may disrupt physiological processes and biochemical metabolism in rice plants, including the emergence of plant resistance gene expression such as OsAB13 and OsLEA, the formation of ROS (Reactive Oxygen Species), namely hydrogen peroxide (H₂O₂), as well as the emergence of gene expression related to antioxidant enzyme activity such as OsAPX1, OsCATA, Mn-SOD, Cu/Zn-SOD, and APX Cytosolic. Besides the emergence of plant resistance gene expression, ROS, and changes in gene expression related to antioxidant enzymes, rice plants also produce salicylic acid which acts as an endogenous signal to activate plant resistance gene responses and can encourage plant resistance responses such as antioxidant enzyme activity. The treatments in this study included: control, 15% PEG 6000, 15% PEG 6000 + SA 1 mM, and SA 1 mM. The results showed that the interaction between treatments and rice plant varieties significantly affected plant height, root length, total chlorophyll, and H₂O₂ content. The expression of the OsAPX1, OsCATA, Mn-SOD, and Cu/Zn-SOD genes increased in the 15% PEG 6000 treatment compared to the control. In the 15% PEG 6000 + SA 1 mM treatment, there was an increase in gene expression of APX Cytosolic, Cu/Zn-SOD, and OsCATA compared to the 15% PEG 6000 treatment. The OsLEA is expressed in Siakraya and Sertani 1 as an indicator of resistance to drought stress, and the OsAB13 is expressed in Indragiri, Sertani 1, and Siakraya varieties as an indicator of resistance to drought stress.

Key words:

and rice plants, antioxidant enzymes, drought stress, reactive oxygen species, resistance genes