State Key Laboratory for Conservation and Utilization of Subtropical Agricultural Bioresources, College of Agriculture, South China Agricultural University, Guangzhou 510642, China.
Scientific Observing and Experimental Station of Crop Cultivation in South China, Ministry of Agriculture, Guangzhou 510642, China.
J Agric Food Chem. 2024 May 8;72(18):10521-10530. doi: 10.1021/acs.jafc.3c08637. Epub 2024 Apr 24.
2-Acetyl-1-pyrroline (2-AP) is a key volatile organic compound in fragrant rice aroma. However, the effects of temperature on 2-AP biosynthesis in fragrant rice and its regulation mechanism have been rarely reported. In the present study, three fragrant rice varieties were used as plant materials, and four temperature treatments during the grain-filling stage, i.e., (T1) 22/17 °C, (T2) 27/22 °C, (T3) 32/27 °C, and (T4) 37/32 °C, were adopted. The results showed that grain contents of 2-AP, proline, and γ-aminobutyric acid (GABA) significantly ( < 0.05) increased with decreased temperature, while the lowest and highest 2-AP contents were recorded in the T4 and T1 treatments, respectively. Higher pyrroline-5-carboxylic acid (P5C) content was recorded in low-temperature treatments (T1 and T2) than in high-temperature treatments (T3 and T4). The transcript levels of genes , , and significantly ( < 0.05) decreased with decreased temperature. Lower transcript levels of genes , , , , and were recorded in low-temperature treatments (T1 and T2) than in high-temperature treatments (T3 and T4). In conclusion, low temperature increased 2-AP content and high temperature decreased 2-AP content in fragrant rice. We deduced that temperature regulated 2-AP biosynthesis through the metabolism of proline and GABA.
2-乙酰基-1-吡咯啉（2-AP）是香米香气中的关键挥发性有机化合物。然而，温度对香米中 2-AP 生物合成的影响及其调控机制鲜有报道。本研究以三个香米品种为材料，在灌浆期采用四个温度处理，即（T1）22/17℃、（T2）27/22℃、（T3）32/27℃和（T4）37/32℃。结果表明，2-AP、脯氨酸和γ-氨基丁酸（GABA）的含量随温度降低而显著增加（<0.05），而 2-AP 含量最低和最高的分别出现在 T4 和 T1 处理中。在低温处理（T1 和 T2）中，吡咯啉-5-羧酸（P5C）的含量高于高温处理（T3 和 T4）。基因、、和的转录水平随温度降低而显著降低（<0.05）。在低温处理（T1 和 T2）中，基因、、、和的转录水平低于高温处理（T3 和 T4）。综上所述，低温增加了香米中 2-AP 的含量，高温降低了香米中 2-AP 的含量。我们推断，温度通过脯氨酸和 GABA 的代谢来调节 2-AP 的生物合成。
