College of Enology, Northwest A&F University, No. 22 Xinong Road, Yangling, Shaanxi, 712100, China.
College of Enology, Northwest A&F University, No. 22 Xinong Road, Yangling, Shaanxi, 712100, China; China Wine Industry Technology Institute, Room 1606, Zhongguancun Innovation Center, Yinchuan, Ningxia, 750021, China.
Plant Physiol Biochem. 2022 Oct 15;189:1-13. doi: 10.1016/j.plaphy.2022.07.031. Epub 2022 Aug 23.
Sugar synthesis from photosynthesis and its utilization through sugar metabolism jointly determine leaf sugar content, and in contrast, excess sugar represses leaf photosynthesis. Although plant photosynthesis is affected by leaf sugar metabolism, the relationship between sugar metabolism and photosynthetic capacity of different grape genotypes remains unclear. In this study, two grape (Vitis vinifera L.) genotypes 'Riesling' (RI, high sugar content in leaf) and 'Petit Manseng' (PM, low sugar content in leaf) were used to evaluate the relationship between sugar metabolism and photosynthesis. Sugar content, chlorophyll content, photosynthetic parameters, enzyme activity, and gene expression related to sucrose metabolism in leaves were measured, and the correlations between photosynthesis and sugar metabolism were assessed. The contents of sucrose and glucose were significantly higher in RI leaves than in PM leaves, while the fructose content pattern was reversed. Cell wall invertase activity for sucrose hydrolysis and the transcript levels of VvCWINV, VvHTs, VvTMT1, VvFKs, and VvHXK2 were also higher in RI leaves than in PM leaves, whereas that of VvHXK1 mediating glucose phosphorylation, was lower in RI leaves than in PM leaves. Net photosynthetic rate, stomatal conductance, transpiration rate, and chlorophyll content were lower in RI leaves than in PM leaves and negatively correlated with glucose content, and the transcript levels of VvCWINV, VvHTs, VvTMT1, and VvHXK2. In conclusion, this study indicates that leaf sugar metabolism and transport are related to photosynthesis in Vitis vinifera L., which provides a theoretical basis for improving grape photosynthesis.
光合作用合成的糖及其通过糖代谢的利用共同决定了叶片糖含量，相反，过量的糖会抑制叶片光合作用。尽管植物光合作用受到叶片糖代谢的影响，但不同葡萄基因型的糖代谢与光合作用能力之间的关系尚不清楚。在本研究中，使用两个葡萄（Vitis vinifera L.）基因型‘雷司令’（RI，叶片中糖含量高）和‘小芒森’（PM，叶片中糖含量低）来评估糖代谢与光合作用之间的关系。测量了叶片中糖含量、叶绿素含量、光合作用参数、与蔗糖代谢相关的酶活性和基因表达，并评估了光合作用与糖代谢之间的相关性。RI 叶片中的蔗糖和葡萄糖含量明显高于 PM 叶片，而果糖含量的模式则相反。蔗糖水解的细胞壁转化酶活性和 VvCWINV、VvHTs、VvTMT1、VvFKs 和 VvHXK2 的转录水平也在 RI 叶片中高于 PM 叶片，而介导葡萄糖磷酸化的 VvHXK1 在 RI 叶片中的活性则低于 PM 叶片。RI 叶片的净光合速率、气孔导度、蒸腾速率和叶绿素含量均低于 PM 叶片，且与葡萄糖含量呈负相关，同时 VvCWINV、VvHTs、VvTMT1 和 VvHXK2 的转录水平也呈负相关。综上所述，本研究表明，葡萄叶片糖代谢和转运与光合作用有关，为提高葡萄光合作用提供了理论依据。
