College of Life Sciences, Henan Normal University, Xinxiang, 453007, Henan, China.
College of Life Sciences, Henan Normal University, Xinxiang, 453007, Henan, China; State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, 100101, China.
Plant Sci. 2019 Oct;287:110169. doi: 10.1016/j.plantsci.2019.110169. Epub 2019 Jun 13.
During the grain filling stage, high light (HL) usually results in premature leaf senescence and significant yield loss in wheat. To explore the responses of sugar metabolism and the association of sugar accumulation and leaf senescence in HL, the activity and gene expression of sugar metabolism-related enzymes were analyzed when two wheat cultivars Triticum aestivum L. Xiaoyan 54 (XY54, HL tolerant) and Jing 411 (J411, HL sensitive) were transferred from low light (LL) to HL for 28 d. The results showed that the CO assimilation rate, quantity of Rubisco and chlorophyll binding proteins decreased substantially for both cultivars in HL. However, the content of fructose, sucrose, and starch increased dramatically. In addition, the activity of hexokinase, pyruvate kinase, sucrose phosphate synthase, sucrose synthase, and alkaline/neutral invertase increased significantly while the expression of most of the sugar metabolism-related genes were repressed by long-term HL. Correlation analysis revealed that sugar content and sucrose phosphate synthase activity were negatively while the expression of most sugar metabolism-related genes were positively correlated with chlorophyll content during HL treatment. Comparatively, the HL tolerant cultivar XY54 accumulated less sugars than the HL sensitive cultivar J411, suggesting that sugar metabolism may be the regulation target for wheat improvement to cope with HL stress.
在灌浆期，高光（HL）通常会导致小麦过早衰老和产量显著损失。为了探讨 HL 下糖代谢的响应以及糖积累与叶片衰老的关系，当两个小麦品种 Triticum aestivum L. Xiaoyan 54（XY54，HL 耐性）和 Jing 411（J411，HL 敏感）从低光（LL）转移到 HL 28 天时，分析了糖代谢相关酶的活性和基因表达。结果表明，两个品种在 HL 下 CO 同化率、Rubisco 数量和叶绿素结合蛋白大幅下降。然而，果糖、蔗糖和淀粉的含量显著增加。此外，己糖激酶、丙酮酸激酶、蔗糖磷酸合成酶、蔗糖合酶和碱性/中性转化酶的活性显著增加，而大多数糖代谢相关基因的表达在长期 HL 下受到抑制。相关性分析表明，在 HL 处理期间，糖含量和蔗糖磷酸合成酶活性与叶绿素含量呈负相关，而大多数糖代谢相关基因的表达与叶绿素含量呈正相关。相比之下，HL 耐性品种 XY54 积累的糖比 HL 敏感品种 J411 少，这表明糖代谢可能是小麦改良以应对 HL 胁迫的调控目标。
