Agronomic, Transcriptomic and Metabolomic Expression Analysis of Aroma Gene (badh2) under Different Temperature Regimes in Rice

摘要

Aroma of rice is controlled by the badh2 gene and its expression is highly influenced by the environmental factors, genotypic condition and cultivation practice. The effects of environmental factors such as salinity, water, aging, heat, cold and shading on 2AP concentration or badh2 gene expression or agronomic traits were investigated individually but the effects of the optimum temperature (20°C to 30°C) were not studied extensively. Therefore, this study investigated the consequences of three different temperatures (ambient or 28.29 ± 0.91°C, 25°C and 20°C) on agronomic performance, badh2 gene expression, 2AP concentration and phenotypic aroma score of five aromatic and a non-aromatic (control) rice genotype. The agronomic performance such as the flowering days (121.60), days to maturity (151.20), plant height (119.80 cm), panicle length (34.80 cm), fertile grain per panicle (151.40), 1000 grain weight (32.67 g) and grain yield per plant (76.73 g) were higher at 25°C temperature compared to the ambient and 20°C temperature. The maximum down-regulation of badh2 gene (-12.20 ± 0.01 fold), the highest concentration of 2AP (0.14 ± 0.02 ppm) and the excellent phenotypic aroma score (score 4) was also observed at 25°C temperature. Hence, the badh2 gene expression level and 2AP concentration were influenced by the temperature, which also regulated the phenotypic expression of aroma and agronomic performance of aromatic rice. This information will enlighten the consequences of optimum temperature and the possible reasons of variation in aroma quality of rice, which could open the possibility of high quality aromatic rice production around the globe..