Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, School of Life Sciences, South China Normal University, Guangzhou, 510631, China.
College of Life Science, Zhao Qing University, Zhaoqing, 526061, China.
Chemosphere. 2020 Jun;249:126540. doi: 10.1016/j.chemosphere.2020.126540. Epub 2020 Mar 18.
Hybridization is common between invasive and native species and may be accompanied by invasive evolution. The hybrid of Sphagneticola trilobata (alien invasive species) and Sphagneticola calendulacea (indigenous congener) was found in South China. According to previous studies, the hybrid performed weak environmental adaptability in comparison with parents. However, based on the results from this study, the hybridization significantly improved the tolerance of the hybrid to cadmium (Cd) stress (200 μmol L). Under Cd stress, the hybrid lines showed lowest level of oxidative damage and the highest level of photosynthetic efficiency. Compared with the parents, the hybrid utilized more active detoxification strategies, such as the cell walls of the leaves and roots adsorbed 88% and 95% Cd, respectively, reducing the amount of Cd entering cells; moreover, most of the Cd that entered cells was transformed into less toxic chemical forms through the reduction of the highly toxic chemical forms; furthermore, it accumulated a large number of phytochelatins to bind Cd and reduced the damage of organelles by Cd. The results demonstrate that hybridization between S. trilobata and S. calendulacea improved the adaptability of the new hybrid species to Cd stress and may pose a greater threat to the survival of the native parent species in the presence of serious water and soil pollution.
杂交在入侵种和本地种之间很常见，并且可能伴随着入侵种的进化。在中国南方发现了三叶鬼针草（外来入侵种）和金纽扣（本地同种）的杂交种。根据之前的研究，与亲本相比，杂种在环境适应性方面表现出较弱的能力。然而，根据本研究的结果，杂交显著提高了杂种对镉（Cd）胁迫的耐受性（200μmol/L）。在 Cd 胁迫下，杂种系表现出最低水平的氧化损伤和最高水平的光合作用效率。与亲本相比，杂种利用了更多的主动解毒策略，例如叶片和根部细胞壁分别吸附了 88%和 95%的 Cd，从而减少了进入细胞的 Cd 量；此外，进入细胞的大部分 Cd 通过将高毒性化学形式还原为毒性较低的化学形式而转化为毒性较低的化学形式；此外，它积累了大量的植物螯合肽来结合 Cd，并减少 Cd 对细胞器的损伤。结果表明，三叶鬼针草和金纽扣之间的杂交提高了新杂种对 Cd 胁迫的适应能力，并且在严重的水和土壤污染存在的情况下，可能对本地亲本地种的生存构成更大的威胁。
