Transcription Factor OsbZIP60-like Regulating Gene and 2-Acetyl-1-pyrroline (2-AP) Biosynthesis in Aromatic Rice.

The most important volatile in determining the aroma of fragrant rice is 2-Acetyl-1-pyrroline (2-AP); however, the transcriptional regulation mechanism of 2-AP biosynthesis in fragrant rice is still unclear. In this study, knockout mutant lines and over-expression lines were constructed by the genetic transformation of the Indica rice cultivar, i.e., 'Zhonghua11', which knocks out to produce fragrance in aromatic rice. The gene was also identified as a key gene in the 2-AP biosynthesis pathway of aromatic rice. The promoter was used as bait, and the OsbZIP60-like transcription factor was screened by yeast one-hybrid assays. The OsbZIP60-like transcription factor specifically bound to the gene. The dual luciferase reporting system found that the OsbZIP60-like transcription factor promoted the transcriptional activation of . Compared with the wild type, gene expression was significantly down-regulated in the -like mutant and resulted in a substantial reduction in 2-AP biosynthesis. Moreover, the gene expression was significantly up-regulated in -like over-expressed plants, and the 2-AP concentrations were also increased, whereas the -like mutants were found to be sensitive to Zn deficiency. Overall, the OsbZIP60-like transcription factor promoted the 2-AP accumulation. This study provides a theoretical basis for the transcriptional regulation mechanism of 2-AP biosynthesis and explores the function of the OsbZIP transcription factor in fragrant rice.