The study was performed to analyze the impact of seed pretreatment by static magnetic field (SMF) of 200 mT for 1 h on photosynthetic performance of soybean (Glycine max) seedlings under ambient (_aUV-B) and supplemental ultraviolet-B (_a+sUV-B) stress. Ambient and supplemental UV-B were found to decrease the plant growth, chlorophyll concentration, PSII efficiency, selected JIP-test parameters such as F_v/F_m, φEo, ΔV(I–P), PI_ABS, PI_total, and rate of photosynthesis in the leaves of soybean seedlings emerged from untreated (UT) seeds. _aUV-B and _a+sUV-B were observed to increase the synthesis of UV-B-absorbing substances (UAS), reactive oxygen species (ROS) like superoxide radical (O₂^·−) and hydrogen peroxide (H₂O₂), antioxidants like ascorbic acid and α-tocopherol and decrease the nitrate reductase (NR) activity; subsequently, it results in a decreased rate of photosynthesis, biomass accumulation, and yield. However, our results provided evidence that SMF pretreatment increased the tolerance of soybean seedlings to UV-B radiation by increased NO content and NR activity; higher efficiency of PSII, higher values of φEo, ΔV(I–P), PI_ABS, and PI_total, decreased intercellular CO₂ concentration, lower amount of UAS, ROS, and antioxidants that consequently improve the yield of soybean plants under _aUV-B as well as _a+sUV-B stress. Thus, our results suggested that SMF pretreatment mitigates the adverse effects of UV-B stress by the enhancement in photosynthetic performance along with higher NO content which may be able to protect the plants from the deleterious effects of oxidative stress caused by UV-B irradiation.

本研究旨在分析 200 mT 静磁场 (SMF) 预处理种子 1 h 对大豆 ( Glycine max ) 幼苗在环境 ( _a UV-B) 和补充紫外线 -B ( _a+)下光合性能的影响。 _UV -B）压力。发现环境和补充 UV-B 会降低植物生长、叶绿素浓度、PSII 效率，选定的 JIP 测试参数，如F _v / F _m 、 φ Eo、Δ V ( I – P )、PI _ABS 、 PI_总量、未经处理（UT）种子的大豆幼苗叶子的光合作用速率。 _a UV-B 和_a+s UV-B 被观察到增加了 UV-B 吸收物质 (UAS)、活性氧 (ROS) 如超氧自由基 (O ₂ ^·− ) 和过氧化氢 (H ₂ O) 的合成₂ ）、抗坏血酸和α-生育酚等抗氧化剂，降低硝酸还原酶（NR）活性；随后，它会导致光合作用、生物量积累和产量下降。然而，我们的结果证明，SMF 预处理通过增加 NO 含量和 NR 活性来提高大豆幼苗对 UV-B 辐射的耐受性； PSII 效率更高， φ Eo、Δ V ( I – P )、PI _ABS和 PI_总值更高，细胞间 CO ₂浓度降低，UAS、ROS 和抗氧化剂含量降低，从而提高了大豆植株的产量_a UV-B 以及_a+s UV-B 压力。 因此，我们的结果表明，SMF 预处理通过增强光合作用性能和更高的 NO 含量来减轻 UV-B 胁迫的不利影响，这可能能够保护植物免受 UV-B 照射引起的氧化胁迫的有害影响。