Aromatic rice belongs to a small but important sub-group of rice, which is highly regarded for its excellent aroma and superior grain quality. Aromatic rice, especially Basmati- and Jasmine-type rice, is being traded at a high price in the local and global markets. Genetically, rice aroma is a phenotypical expression of spontaneous recessive mutations of the OsBadh2 gene (also known as fgr/badh2/osbadh2/os2AP gene). These mutations inhibit the flow of γ-aminobutyraldehyde (GAB-ald) to γ-aminobutyric acid (GABA), and consequently, the accumulated GAB-ald is diverted to a potent flavour component 2-acetyl-1-pyrroline (2AP) by a non-enzymatic reaction with methylglyoxal. The natural incidence of non-functional osbadh2 mutation along with selection and nursing by the farmer from the ancient time makes rice aroma as a prominent natural gift. As GABA and methylglyoxal play significant roles in stress tolerance, and their biosynthesis is strictly regulated in rice plants, the accumulation of 2AP in aromatic rice depends on the interaction of various genetic and environmental factors, and its production may come at some costs of sacrificing tolerance. This review focused on some potential underlying genes in the 2AP and GABA biosynthesis pathways, and analyzed most aspects of aroma formation in rice, and summarized the molecular mechanism of aroma production together with its genetic and non-genetic influencing factors. The present review also stated approaches to produce high-quality aromatic rice via developing novel cultivars and with good agronomic knowledge-based practice.

香米属于一小部分重要的米类，以其出色的香气和优质的谷物而备受推崇。芳香米，尤其是印度香米和茉莉香米，在本地和全球市场上都以高价交易。从基因上讲，稻香是OsBadh2基因（也称为fgr / badh2 / osbadh2 / os2AP基因）的自发性隐性突变的表型表达。这些突变抑制的流动γ -aminobutyraldehyde（GAB-ALD）到γ-氨基丁酸（GABA），因此，通过与甲基乙二醛的非酶反应将积累的GAB-ald转移到有效的风味成分2-乙酰基-1-吡咯啉（2AP）中。非功能性osbadh2的自然发生率从远古时代开始，农民就进行了选择和护理，从而使大米的香气成为重要的天然礼物。由于GABA和甲基乙二醛在胁迫耐受性中起着重要作用，并且它们的生物合成在水稻植物中受到严格调节，因此芳香族水稻中2AP的积累取决于各种遗传和环境因素的相互作用，其产生可能以牺牲耐受性为代价。这篇综述着重于2AP和GABA生物合成途径中潜在的潜在基因，并分析了稻米香气形成的大多数方面，总结了香气产生的分子机制以及其遗传和非遗传影响因素。