Xie Wenjun, Ashraf Umair, Zhong Dating, Lin Rongbin, Xian Peiqi, Zhao Tong, Feng Huoyi, Wang Shuli, Duan Meiyang, Tang Xiangru, Mo Zhaowen
College of Agriculture South China Agricultural University Guangzhou China.
Department of Botany Division of Science and Technology University of Education Lahore, Punjab Pakistan.
Food Sci Nutr. 2019 Oct 22;7(11):3784-3796. doi: 10.1002/fsn3.1240. eCollection 2019 Nov.
The 2-acetyl-1-pyrroline (2AP) is a key aroma compound in fragrant rice. The present study assessed the γ-aminobutyric acid (GABA) and nitrogen (N) application induced regulations in the biochemical basis of rice aroma formation. Four N levels, that is, 0, 0.87, 1.75, and 2.61 g/pot, and two GABA treatments, that is, 0 mg/L (GABA0) and 250 mg/L (GABA250), were applied to three fragrant rice cultivars, that is, Yuxiangyouzhan, Yungengyou 14, and Basmati-385. Results showed that GABA250 increased 2AP, Na, Mn, Zn, and Fe contents by 8.44%, 10.95%, 25.70%, 11.14%, and 43.30%, respectively, under N treatments across cultivars. The GABA250 further enhanced the activities of proline dehydrogenase (PDH), ornithine aminotransferase (OAT) (both at 15 days after heading (d AH), and diamine oxidase (DAO) (at maturity) by 20.36%, 11.24%, and 17.71%, respectively. Significant interaction between GABA and N for Mn, Zn, and Fe contents in grains, proline content in leaves, GABA content in leaves at 15 d AH and maturity stage (MS), Δ1-pyrroline-5-carboxylic acid (P5C) contents in leaves at 15 d AH, and Δ1-pyrroline-5-carboxylate synthase (P5CS), PDH, and OAT activities in leaves at MS was noted. Moreover, the 2AP contents in grains at MS showed a significant and positive correlation with the proline contents in the leaves at 15d AH. In conclusion, GABA250 enhanced the 2AP, Na, Mn, Zn, and Fe contents, as well as the enzyme activities involved in 2AP biosynthesis. Exogenous GABA and N application improved the 2AP contents and nutrient uptake in fragrant rice.
2-乙酰基-1-吡咯啉（2AP）是香稻中的一种关键香气化合物。本研究评估了γ-氨基丁酸（GABA）和氮（N）的施用对水稻香气形成生化基础的调控作用。对三个香稻品种，即玉香油占、云粳优14和巴斯马蒂-385，施加了四个氮水平，即0、0.87、1.75和2.61克/盆，以及两种GABA处理，即0毫克/升（GABA0）和250毫克/升（GABA250）。结果表明，在各品种的氮处理下，GABA250使2AP、钠、锰、锌和铁含量分别增加了8.44%、10.95%、25.70%、11.14%和43.30%。GABA250还使脯氨酸脱氢酶（PDH）、鸟氨酸转氨酶（OAT）（均在抽穗后15天（d AH））和二胺氧化酶（DAO）（在成熟期）的活性分别进一步提高了20.36%、11.24%和17.71%。在籽粒中的锰、锌和铁含量、叶片中的脯氨酸含量、抽穗后15天和成熟期（MS）叶片中的GABA含量、抽穗后15天叶片中的Δ1-吡咯啉-5-羧酸（P5C）含量以及成熟期叶片中的Δ1-吡咯啉-5-羧酸合酶（P5CS）、PDH和OAT活性方面，发现GABA和氮之间存在显著的交互作用。此外，成熟期籽粒中的2AP含量与抽穗后15天叶片中的脯氨酸含量呈显著正相关。总之，GABA250提高了2AP、钠、锰、锌和铁的含量以及参与2AP生物合成的酶活性。外源施用GABA和氮提高了香稻中的2AP含量和养分吸收。
