Metabolic Rewiring of the Shikimate Pathway Enables Rose‐Scented Rice
Xiaoqing Cui, Wenhao Yao, Honglin Yang, Yangning Ou, Keyi Chen, Yifei Qin, Chengxuan Li, Boxi Zhu, Wenyi Wang, Jiayang Li, Mengyun Xu, Jian WuABSTRACT
Rice fragrance is a key determinant of grain quality, yet the aroma profile of cultivated rice is highly uniform and largely dominated by the popcorn‐like compound 2‐acetyl‐1‐pyrroline. Here we expanded the aromatic repertoire of rice by engineering a rose‐like fragrance through reconstruction of the phenylalanine‐derived 2‐phenylethanol (2‐PE) pathway in the endosperm. To increase phenylalanine precursor supply, we co‐expressed an engineered G211R/G212S variant of the rice 3‐deoxy‐D‐arabino‐heptulosonate 7‐phosphate synthase isoform OsDHS2 ( LOC_Os08g37790 ; mOsDHS2) with heterologous phenylacetaldehyde synthase (PAAS) and phenylacetaldehyde reductase (PAR) in the endosperm. As a result, the engineered grains accumulated up to 2014 μg/kg 2‐PE, conferring a distinct rose‐like aroma. Unexpectedly, metabolic rewiring also reshaped grain composition, resulting in nearly doubled soluble protein content and increased levels of several vitamin B6‐related metabolites, including the active coenzyme forms pyridoxal 5′‐phosphate and pyridoxamine 5′‐phosphate. These findings reveal extensive associated metabolic coordination between aromatic amino acid pathways and central seed metabolism. Our work establishes a strategy for creating designer fragrances in staple crops while simultaneously improving nutritional traits, providing a versatile platform for producing high‐value metabolites in cereal grains.