DataSheet_1_Heterologous overexpression of Apocynum venetum flavonoids synthetase genes improves Arabidopsis thaliana salt tolerance by activating the IAA and JA biosynthesis pathways.pdf

Salt stress is a serious abiotic stress that primarily inhibits plant growth, resulting in severe yield losses. Our previous research found that flavonoids play important roles in A. venetum salt stress tolerance. In response to salt stress, we noted that the flavonoid content was depleted in A. venetum. However, the detailed mechanism is still not clear. In this study, the expression patterns of three flavonoids synthetase genes, AvF3H, AvF3’H, and AvFLS were systemically analyzed under salt stress in A. venetum seedlings. The salt tolerance of transgenic Arabidopsis plants was improved by heterologous overexpression of these synthetase genes. The NBT and DAB staining results as well as H2O2 and O2•- content analysis revealed that under salt stress, ROS molecules were reduced in transgenic plants compared to WT plants, which corresponded to the activation of the antioxidant enzyme system and an increase in total flavonoid content, particularly rutin, eriodictyol, and naringerin in transgenic plants. External application of flavonoids reduced ROS damage in WT plants just like what we observed in the transgenic plants (without the external application). Additionally, our transcriptome analysis demonstrated that auxin and jasmonic acid biosynthesis genes, as well as signaling transduction genes, were primarily activated in transgenic plants under salt stress, leading to activation of the cell wall biosynthesis or modification genes that promote plant growth. As a result, we investigated the mechanism through flavonoids enhance the salt tolerance, offering a theoretical foundation for enhancing salt tolerance in plants.

盐胁迫作为一种严重的非生物胁迫，主要抑制植物生长，导致严重的产量损失。本研究的前期研究发现，黄酮类化合物在A. venetum的盐胁迫耐受性中发挥着重要作用。在应对盐胁迫的过程中，我们观察到A. venetum中的黄酮含量有所减少，但其详细机制尚不明确。本研究系统分析了在盐胁迫条件下A. venetum幼苗中三种黄酮合成酶基因（AvF3H、AvF3’H和AvFLS）的表达模式。通过异源过表达这些合成酶基因，转基因拟南芥植物的耐盐性得到了提升。NBT和DAB染色结果以及H2O2和O2•-含量分析显示，与野生型植物相比，转基因植物在盐胁迫下ROS分子的含量降低，这与抗氧化酶系统的激活和总黄酮含量的增加相对应，特别是在转基因植物中，槲皮素、橙黄酮和柚皮苷的含量增加。外源应用黄酮类化合物同样能够减少野生型植物中的ROS损伤，这与我们在转基因植物中观察到的结果一致（未进行外源应用）。此外，我们的转录组分析表明，在盐胁迫条件下，转基因植物中生长素和茉莉酸生物合成基因，以及信号转导基因主要被激活，进而激活了细胞壁生物合成或修饰基因，这些基因的激活促进了植物的生长。因此，本研究探讨了黄酮类化合物增强植物耐盐性的机制，为提高植物耐盐性提供了理论依据。