Iwuala Emmanuel, Olajide Olubunmi, Abiodun Isaika, Odjegba Victor, Utoblo Obaiya, Ajewole Tolulope, Oluwajobi Ayoola, Uzochukwu Sylvia
Department of Plant Science and Biotechnology, Federal University Oye Ekiti, Nigeria.
Department of Landscape and Horticulture, Ekiti State University, Ekiti, Nigeria.
Heliyon. 2024 Jan 30;10(3):e25514. doi: 10.1016/j.heliyon.2024.e25514. eCollection 2024 Feb 15.
Cadmium (Cd) stress is a significant environmental pollutant that can negatively impact crop yield and growth, and is a serious global issue. However, silicon (Si) has been shown to have a potential function in alleviating the effects of several abiotic stress conditions on crops, including Cd stress. This study investigated the effectiveness of applying silicon to soil as a method for reducing cadmium toxicity in pearl millet (IP14599) seedlings. Seeds of IP14599 were treated with Si + Cd element which cumulated to a combination of 9 treatments. Different Cd concentration of (0, 200, and 300 mg/kg-) was taken and manually mixed into a sieved soil prior to planting and Si (0, 100 and 200 mg/kg-) was selectively introduced till after attaining 12 days of seedling emergence. The physiochemical parameters of Cd stressed plants investigated includes chlorophyll, gas exchange attributes, proline, relative water contents, malondialdehyde (MDA) content and antioxidant enzymes (superoxide dismutase (SOD),catalase (CAT), ascorbate peroxidase (APX), peroxidase (POD). Our result revealed that the metal (Cd) caused serious oxidative impairment thereby reducing photosynthetic performance, increased activity of MDA and Cd content in the roots and leaves of IP14599.In addition, Si increased the growth pattern and antioxidant defense action thereby mitigating the Cd toxicity. The results revealed that at Si 200, Si significantly increased the chlorophyll, carotenoids and plant height at 122 %, 69 % and 128 % under the Cd 200 and Cd 300 mg/kg- treatment, respectively. The single treatment at Si100 and Si 200 decreased ROS by 29 %, and 37 % respectively and MDA decreased by 33 % and 43 % in contrast to Cd 200 and 300 treatments, respectively. However, Si200 showed significant increase in the activities of APX 97 %, SOD by 89 %, CAT 35 % and POD 86 % as compared to single Si, Cd or combine Cd + Si treatment. Also, a gradual decline in Cd level in both the leaf and root was present when exposed to high concentrations of Si at Si200 and 300 mg/kg-. Our findings revealed that Si might significantly increase the capacity to tolerate Cd stress in crop plants. Therefore, the study revealed that Si has the potential to alleviate Cd-induced toxicity by reducing Cd assimilation and enhancing the growth attributes of IP14599 plants.
镉（Cd）胁迫是一种严重的环境污染物，会对作物产量和生长产生负面影响，是一个严峻的全球性问题。然而，硅（Si）已被证明在减轻包括镉胁迫在内的几种非生物胁迫条件对作物的影响方面具有潜在作用。本研究调查了向土壤中施用硅作为降低珍珠粟（IP14599）幼苗镉毒性方法的有效性。IP14599种子用硅 + 镉元素处理，累积形成9种处理组合。在种植前，将不同镉浓度（0、200和300 mg/kg）人工混入过筛土壤中，并在幼苗出土12天后选择性地施加硅（0、100和200 mg/kg）。所研究的镉胁迫植物的生理化学参数包括叶绿素、气体交换属性、脯氨酸、相对含水量、丙二醛（MDA）含量和抗氧化酶（超氧化物歧化酶（SOD）、过氧化氢酶（CAT）、抗坏血酸过氧化物酶（APX）、过氧化物酶（POD））。我们的结果表明，金属（Cd）造成了严重的氧化损伤，从而降低了光合性能，增加了IP14599根和叶中MDA的活性以及镉含量。此外，硅增加了生长模式和抗氧化防御作用，从而减轻了镉毒性。结果表明，在镉浓度为200和300 mg/kg处理下，施硅量为200时，硅分别使叶绿素、类胡萝卜素和株高显著增加了122%、69%和128%。与镉浓度为200和300 mg/kg的处理相比，单独施用硅100和硅200分别使活性氧减少了29%和37%，MDA分别减少了33%和43%。然而，与单独施硅、镉或镉 + 硅组合处理相比，硅200使APX活性显著增加了97%，SOD增加了89%，CAT增加了35%，POD增加了86%。此外，当施硅量为200和300 mg/kg时，叶片和根系中的镉含量均逐渐下降。我们的研究结果表明，硅可能会显著提高作物对镉胁迫的耐受能力。因此，该研究表明，硅有可能通过减少镉的吸收和增强IP14599植物的生长属性来减轻镉诱导的毒性。
