Herein, we designed and prepared a magnesium and nitrogen co-doped carbon dots (Mg,N-CDs) for plant photosynthesis, in which Mg and N were in carbonate-like and graphite N forms with 5.38% and 3.83% contents, respectively. During a 1-h incubation with chloroplast suspension, Mg,N-CDs entered chloroplasts and transferred energy to them under a xenon lamp, which increased their photosynthetic activity to reduce DCPIP and ferricyanide by up to 52.48% and 41.86%, respectively. After 16 days of foliar spraying, Mg,N-CDs at 300 μg·mL⁻¹ up-regulated the gene expressions of enzymes (15.26–115.02%) related to chlorophyll synthesis and metabolism in rice plants, increasing chlorophyll a and chlorophyll b contents by 14.39% and 26.54%, respectively. The rice seedlings treated with Mg,N-CDs at 300 μg·mL⁻¹ exhibited 109.54%, 104.48%, and 127.16% higher photosynthetic activity, electron transport rate, and photosynthetic efficiency relative to the control, respectively. Moreover, Mg,N-CDs also increased the RuBisCO activity of rice plants by 46.62%. With the energy transformation and physiological regulation, Mg,N-CDs (300 μg·mL⁻¹) increased the height and fresh biomass of rice plants by 22.34% and 70.60%, respectively, through the overall improvement of photosynthesis. This study suggests the great potential of Mg,N-CDs in increasing global agricultural production in the future.

在这里，我们设计并制备了用于植物光合作用的镁和氮共掺杂碳点（Mg，N-CDs），其中Mg和N呈碳酸盐状，石墨N形式的含量分别为5.38％和3.83％。在与叶绿体悬浮液孵育1小时的过程中，Mg，N-CDs在氙气灯下进入叶绿体并向其传递能量，这增加了它们的光合活性，分别降低了DCPIP和铁氰化物达52.48％和41.86％。叶面喷施16天后，300μg·mL ^-1的Mg，N-CDs上调了水稻叶片中与叶绿素合成代谢相关的酶的基因表达（15.26–115.02％），增加了叶绿素a和叶绿素b的表达。含量分别为14.39％和26.54％。Mg，N-CDs 300μg·mL ^-1处理的水稻幼苗的光合活性，电子传递速率和光合效率分别比对照高109.54％，104.48％和127.16％。此外，Mg，N-CDs也使水稻植株的RuBisCO活性提高了46.62％。通过能量转化和生理调节，通过光合作用的整体改善，Mg，N-CDs（300μg·mL ^-1）分别使稻株的株高和新鲜生物量分别提高了22.34％和70.60％。这项研究表明，Mg，N-CDs在未来增加全球农业产量方面具有巨大潜力。