Sothern Regional Collaborative Innovation Center for Grain and Oil Crops (CICGO), Hunan Agricultural University, Changsha, 410128, China.
Sci Rep. 2019 Feb 25;9(1):2700. doi: 10.1038/s41598-019-38883-2.
Amino acid content in grains is an important nutritional quality trait in rice. High temperature can affect rice quality by accelerating grain filling. However, there is limited information available on the influence of high temperature on amino acid content in rice grains, especially under natural conditions. In this study, grain-filling traits and amino acid content in the grain of two rice cultivars (Luliangyou 996 and Lingliangyou 268) were compared between two years (2016 and 2017) with contrasting temperatures during the early grain-filling period under field conditions. Average daily mean temperature during the period of 0-5 days after full heading in 2016 (30.1 °C) was 5.4 °C higher than that in 2017. Initial, maximum, and mean grain-filling rates were 42-307% higher in 2016 than in 2017 for Luliangyou 996 and Lingliangyou 268. The time taken to reach the maximum grain-filling rate and active grain-filling duration were 6.3-10.7 d shorter in 2016 compared to 2017 for Luliangyou 996 and Lingliangyou 268. Grain weight was equal to or significantly higher in 2016 than in 2017 for Luliangyou 996 and Lingliangyou 268. N accumulation and N content in the grain were significantly lower in 2016 than in 2017 for both cultivars. The grain contents of all detected amino acids, except for methionine in Luliangyou 996, were significantly lower in 2016 than in 2017. Our study suggests that high temperature during the early grain-filling period can result in an accelerated grain-filling process, reduced N accumulation and content in rice grains, and consequently reduced amino acid content in the grain.
谷物中的氨基酸含量是稻米重要的营养品质性状。高温可以通过加速灌浆来影响稻米品质。然而，关于高温对稻米籽粒中氨基酸含量的影响，特别是在自然条件下的影响，信息有限。在本研究中，比较了两个水稻品种（绿两优 996 和陵两优 268）在 2016 年和 2017 年两个年份的田间条件下，在灌浆早期高温期（抽穗后 0-5 天）的粒型特征和籽粒氨基酸含量。2016 年的平均日平均气温（30.1°C）比 2017 年高 5.4°C。绿两优 996 和陵两优 268 在 2016 年的初始、最大和平均灌浆速率分别比 2017 年高 42-307%。绿两优 996 和陵两优 268 在 2016 年达到最大灌浆速率和活跃灌浆持续时间分别比 2017 年少 6.3-10.7d。2016 年的籽粒重量与 2017 年相等或显著高于 2017 年。两个品种的氮积累量和籽粒氮含量在 2016 年均显著低于 2017 年。除绿两优 996 中的蛋氨酸外，所有检测到的氨基酸在 2016 年的含量均显著低于 2017 年。本研究表明，灌浆早期高温会导致灌浆过程加速，水稻籽粒中氮积累和含量减少，进而导致籽粒中氨基酸含量降低。
