Guo Jian, Qu Lingling, Wei Qi, Lu Dalei
Jiangsu Key Laboratory of Crop Genetics and Physiology/Jiangsu Key Laboratory of Crop Cultivation and Physiology/Agricultural College, Yangzhou University, Yangzhou, China.
Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, Yangzhou University, Yangzhou, China.
Front Plant Sci. 2022 Nov 4;13:988172. doi: 10.3389/fpls.2022.988172. eCollection 2022.
Waxy maize has many excellent characteristics in food and nonfood industries. However, post-silking low temperature (LT) has severe limitations on its grain yield and quality. In this study, field and pot trials were conducted to investigate the effects of post-silking LT on the physiological, biochemical, and functional characteristics of two waxy maize grains. The field and pot trials were performed with sowing date and artificial climate chamber, respectively, for LT treatment from silking stage to maturity. Results in pot trial were used to explain and validate the findings in field trial. Compared with the ambient treatment, the LT treatment significantly reduced kernel weight during the grain filling stage ( < 0.05). LT treatment in both environments resulted in an average decrease in dry weight of SYN5 and YN7 at maturity by 36.6% and 42.8%, respectively. Enzymatic activities related to starch and protein biosynthesis decreased under the LT treatment during the filling stage, accompanied by a decrease in the accumulation amounts and contents of soluble sugar and starch, and a decrease in protein accumulation amount. Meanwhile, the contents of abscisic acid, indole-3-acetic acid, and gibberellin 3 in grains decreased under the LT treatment during the filling stage. Peak, trough, breakdown, final, and setback viscosities of grains decreased by LT. LT treatment decreased the gelatinization enthalpy of grains and increased the retrogradation percentage. In conclusion, post-silking LT stress altered the content of grain components by inhibiting the production of phytohormones and down-regulating the enzymatic activities involved in starch and protein metabolism, which resulted in the deterioration of grain pasting and thermal properties.
糯玉米在食品和非食品工业中具有许多优良特性。然而，抽丝后低温对其籽粒产量和品质有严重限制。本研究通过田间试验和盆栽试验，研究抽丝后低温对两种糯玉米籽粒生理、生化和功能特性的影响。田间试验和盆栽试验分别通过播种期和人工气候箱进行，对抽丝期至成熟期进行低温处理。盆栽试验结果用于解释和验证田间试验结果。与常温处理相比，低温处理显著降低了灌浆期的粒重（<0.05）。两种环境下的低温处理均导致SYN5和YN7成熟时干重平均分别下降36.6%和42.8%。灌浆期低温处理下与淀粉和蛋白质生物合成相关的酶活性降低，同时可溶性糖和淀粉的积累量和含量下降，蛋白质积累量减少。同时，灌浆期低温处理下籽粒中脱落酸、吲哚-3-乙酸和赤霉素3的含量降低。低温使籽粒的峰值、低谷、崩解、最终和回生粘度降低。低温处理降低了籽粒的糊化焓，增加了回生百分比。总之，抽丝后低温胁迫通过抑制植物激素的产生和下调参与淀粉和蛋白质代谢的酶活性，改变了籽粒成分的含量，导致籽粒糊化和热性质恶化。
