Downregulation of badh2 gene is responsible for aroma in Kon Joha rice (Oryza sativa L.) of Assam

The primary cause of aroma in rice grains is the reduced expression of the badh2 gene, which leads to an accumulation of 2-acetyl-1-pyrroline. However, the existence of different mutations in this gene and a few other alternative pathways for 2-acetyl-1-pyrroline biosynthesis have also been suggested. Kon Joha (KJ) is a unique but lesser-studied joha aromatic rice that comes from Assam, an Indian state in the Northeast. In this work, we used differential gene expression profiling to determine the genetic basis of fragrance in KJ. According to our findings, the primary cause of fragrance in Kon Joha is the downregulation of the badh2 gene. Furthermore, we propose two additional genes from the amine metabolic pathway as potential candidates for fragrance in Kon Joha rice based on GO-terms and pathway enrichment analysis. Further studies must focus on determining the exact nature of the mutation in badh2 gene and validate the reported candidate genes.