Analisis Respon Cekaman Salinitas Terhadap Kemampuan Regenerasi Kalus, Ekspresi Gen Enzim Antioksidan dan Metabolit pada Tanaman Padi (Oryza sativa L.)

Abstract

Salinity is one of the abiotic stresses with high levels of salt in the soil, posing a challenge to crop cultivation, especially for rice plants. Rice is a staple crop grown extensively and serves as a source of carbohydrates for a significant portion of the world's population, including Indonesia. Salinity impacts plants by reducing yields due to inhibited growth and development of rice plants. Each plant responds differently to salinity stress, with genetic resilience being advantageous in enhancing plant tolerance to stress. Plant defense responses involve several mechanisms to sustain plant survival against salinity stress, including regulation by antioxidant enzyme genes (OsCATA, CAT, Mn-SOD, Cu/Zn SOD, Cytosolic APX, OsAPX1, and GPX), as well as metabolite genes such as GABA (GABA-T) and increased essential amino acids like proline (P5CS). This study aims to understand responses to salinity stress at the cellular level through in vitro culture to confirm characteristics of callus regeneration ability, expression of antioxidant enzyme genes, and metabolites in rice plants of the Cigeulis variety. Based on the findings, salinity treatment impacts plants as observed from the formation of greenspot and browning, regeneration stages, and embryogenic levels. The results of the gene expression characteristics showed that the IR64 rice variety, when treated with salinity, activated antioxidant enzyme genes and metabolites including Mn-SOD, CAT, OsCATA, Cytosolic APX, OsAPX1, GPX, GABA-T and P5CS, while the Cigeulis rice variety only activated Mn-SOD.