College of Agriculture, Guizhou University, Guiyang, 550025, China.
Key Laboratory of Molecular Breeding for Grain and Oil Crops in Guizhou Province, Guiyang, 550025, China.
BMC Plant Biol. 2024 Sep 10;24(1):850. doi: 10.1186/s12870-024-05551-1.
This study evaluated the responses of sweet potatoes to Cadmium (Cd) stress through pot experiments to theoretically substantiate their comprehensive applications in Cd-polluted agricultural land. The experiments included a CK treatment and three Cd stress treatments with 3, 30, and 150 mg/kg concentrations, respectively. We analyzed specified indicators of sweet potato at different growth periods, such as the individual plant growth, photosynthesis, antioxidant capacity, and carbohydrate Cd accumulation distribution. On this basis, the characteristics of the plant carbon metabolism in response to Cd stress throughout the growth cycle were explored. The results showed that T2 and T3 treatments inhibited the vine growth, leaf area expansion, stem diameter elongation, and tuberous root growth of sweet potato; notably, T3 treatment significantly increased the number of sweet potato branches. Under Cd stress, the synthesis of chlorophyll in sweet potato was significantly suppressed, and the Rubisco activity experienced significant reductions. With the increasing Cd concentration, the function of PS II was also affected. The soluble sugar content underwent no significant change in low Cd concentration treatments. In contrast, it decreased significantly under high Cd concentrations. Additionally, the tuberous root starch content decreased significantly with the increase in Cd concentration. Throughout the plant growth, the activity levels of catalase, peroxidase, and superoxide dismutase increased significantly in T2 and T3 treatments. By comparison, the superoxide dismutase activity in T1 treatment was significantly lower than that of CK. With the increasing application of Cd, its accumulation accordingly increased in various sweet potato organs. The the highest bioconcentration factor was detected in absorbing roots, while the tuberous roots had a lower bioconcentration factor and Cd accumulation. Moreover, the transfer factor from stem to petiole was the highest of the potato organs. These results demonstrated that sweet potatoes had a high Cd tolerance and a restoration potential for Cd-contaminated farmland.
本研究通过盆栽试验评价了甘薯对镉（Cd）胁迫的响应，从理论上为其在 Cd 污染农田的综合应用提供了依据。试验包括 CK 处理和 3、30 和 150mg/kg 浓度的 3 个 Cd 胁迫处理，分析了甘薯不同生长时期的个体生长、光合作用、抗氧化能力和碳水化合物 Cd 积累分布等特定指标。在此基础上，探讨了植物碳代谢对整个生长周期 Cd 胁迫的响应特征。结果表明，T2 和 T3 处理抑制了甘薯藤生长、叶面积扩张、茎径伸长和块根生长；T3 处理显著增加了甘薯分枝数。在 Cd 胁迫下，甘薯叶绿素合成受到明显抑制，Rubisco 活性显著降低。随着 Cd 浓度的增加，PS II 功能也受到影响。低 Cd 浓度处理下，可溶性糖含量无明显变化；而在高 Cd 浓度下，其含量显著降低。此外，块根淀粉含量随 Cd 浓度的增加而显著下降。在整个植物生长过程中，T2 和 T3 处理下过氧化氢酶、过氧化物酶和超氧化物歧化酶的活性水平显著升高。相比之下，T1 处理中超氧化物歧化酶的活性明显低于 CK。随着 Cd 的不断应用，其在各种甘薯器官中的积累也相应增加。吸收根的生物浓缩系数最高，而块根的生物浓缩系数和 Cd 积累量较低。此外，茎到叶柄的转移系数是块根器官中最高的。这些结果表明，甘薯具有较高的 Cd 耐受性和修复 Cd 污染农田的潜力。
