School of Environmental Science and Engineering, Shaanxi University of Science & Technology, Xi'an, 710021, People's Republic of China.
Environ Sci Pollut Res Int. 2021 Oct;28(37):51854-51864. doi: 10.1007/s11356-021-14252-3. Epub 2021 May 15.
In the present study, a hydroponic experiment was performed to evaluate the effect of exogenous silicon (Si) and methyl jasmonate (MeJA) on the mitigation of Cd toxicity in tomato seedlings. The results revealed that Cd-stressed plants exhibited growth inhibition, increased lipid peroxidation, and impaired photosynthetic pigment accumulation. However, Si and MeJA applied alone or in combination significantly ameliorated the above-mentioned adverse effects induced by Cd. Among all treatments, Cd+Si+MeJA treatment elevated the dry mass of roots, stems, and leaves by 317.39%, 110.85%, and 119.71%, respectively. The chlorophyll a, chlorophyll b, and carotenoid contents in Cd+Si+MeJA-treated group were dramatically elevated (p < 0.05). Meanwhile, the malondialdehyde content in roots and shoots were reduced by 32.24% and 69.94%, respectively. The Si and MeJA applied separately or in combination also resulted in a prominent decrease of Cd influxes in tomato roots; therefore, a reduction of Cd content in tomato tissues were detected, and the Cd concentration in tomato roots were decreased by 27.19%, 25.18%, and 17.51% in Cd+Si, Cd+MeJA and Cd+Si+MeJA-treated plants, respectively. Moreover, in Cd+Si+MeJA-treated group, the percentage of Cd in cell wall fraction was enhanced while that in organelle fraction was decreased as compared with Cd-stressed plants. Collectively, our findings indicated that Si and MeJA application provide a beneficial role in enhancing Cd tolerance and reducing Cd uptake in tomato plants.
在本研究中，进行了水培实验以评估外源硅（Si）和茉莉酸甲酯（MeJA）对减轻番茄幼苗镉毒性的影响。结果表明，镉胁迫下的植物表现出生长抑制、脂质过氧化增加和光合色素积累受损。然而，Si 和 MeJA 单独或联合施用可显著改善 Cd 引起的上述不利影响。在所有处理中，Cd+Si+MeJA 处理分别使根、茎和叶的干质量增加了 317.39%、110.85%和 119.71%。Cd+Si+MeJA 处理组的叶绿素 a、叶绿素 b 和类胡萝卜素含量显著升高（p<0.05）。同时，根和茎中的丙二醛含量分别降低了 32.24%和 69.94%。Si 和 MeJA 单独或联合施用也导致番茄根系中 Cd 流入量显著减少；因此，检测到番茄组织中的 Cd 含量降低，Cd+Si、Cd+MeJA 和 Cd+Si+MeJA 处理的番茄根中的 Cd 浓度分别降低了 27.19%、25.18%和 17.51%。此外，在 Cd+Si+MeJA 处理组中，与镉胁迫植株相比，细胞壁部分的 Cd 百分比增加，而细胞器部分的 Cd 百分比降低。综上所述，我们的研究结果表明，Si 和 MeJA 的应用在提高番茄对 Cd 的耐受性和减少 Cd 吸收方面发挥了有益作用。
