Department of Botany, Government College University Faisalabad, 38000, Faisalabad, Pakistan.
Department of Botany, Government College University Faisalabad, 38000, Faisalabad, Pakistan.
Chemosphere. 2022 Dec;308(Pt 3):136523. doi: 10.1016/j.chemosphere.2022.136523. Epub 2022 Sep 19.
Plants essentially require manganese (Mn) for their normal metabolic functioning. However, excess Mn in the cellular environment is detrimental to plant growth, development, and physio-biochemical functions. Taurine (TAU) is an amino acid with potent antioxidant and anti-inflammatory properties in animals and humans. However, no previous study has investigated the potential of TAU in plant metal stress tolerance. The current study provides some novel insights into the effect of TAU in modulating the defense system of Trifolium alexandrinum plants under Mn toxicity. Manganese toxicity resulted in higher oxidative stress and membrane damage through increased superoxide radical, hydrogen peroxide, malondialdehyde, and methylglyoxal generation alongside enhanced lipoxygenase (LOX) activity. Mn toxicity also resulted in limited uptake of potassium (K), phosphorus (P), calcium (Ca), and increased the accumulation of Mn in both leaf and roots. However, TAU circumvented the Mn-induced oxidative stress by upregulating the activities of antioxidant enzymes (ascorbate peroxidase, peroxidase, catalase, glutathione reductase, glutathione-S-transferase, and superoxide dismutase) and levels of ascorbic acid, proline, anthocyanins, phenolics, flavonoids and glutathione (GSH). Taurine conspicuously improved the growth, photosynthetic pigments, hydrogen sulphide (HS), and nitric oxide (NO) levels of Mn stressed plants. Taurine also improved the uptake of K, Ca, P and reduced the Mn content in stressed plants. Overall, exogenous taurine might be a suitable strategy to combat Mn stress in T. alexandrinum plants but applications at field levels for various crops and metal toxicities and economic suitability need to be addressed before final recommendations.
植物的正常新陈代谢基本需要锰(Mn)。然而,细胞环境中过量的 Mn 对植物的生长、发育和生理生化功能有害。牛磺酸(TAU)是一种在动物和人类中具有强大抗氧化和抗炎特性的氨基酸。然而,以前没有研究调查 TAU 在植物金属胁迫耐受中的潜力。本研究为 TAU 在调节 Mn 毒性下三叶草植物防御系统中的作用提供了一些新的见解。Mn 毒性通过增加超氧自由基、过氧化氢、丙二醛和甲基乙二醛的产生以及增强脂氧合酶(LOX)活性,导致更高的氧化应激和膜损伤。Mn 毒性还导致钾(K)、磷(P)、钙(Ca)的吸收受限,并增加了叶片和根部 Mn 的积累。然而,TAU 通过上调抗氧化酶(抗坏血酸过氧化物酶、过氧化物酶、过氧化氢酶、谷胱甘肽还原酶、谷胱甘肽-S-转移酶和超氧化物歧化酶)的活性和抗坏血酸、脯氨酸、花青素、酚类、类黄酮和谷胱甘肽(GSH)的水平来规避 Mn 诱导的氧化应激。牛磺酸显著改善了 Mn 胁迫植物的生长、光合色素、硫化氢(HS)和一氧化氮(NO)水平。牛磺酸还增加了 K、Ca、P 的吸收,并降低了胁迫植物中的 Mn 含量。总的来说,外源性牛磺酸可能是一种对抗 T. alexandrinum 植物 Mn 胁迫的合适策略,但在提出最终建议之前,需要在各种作物和金属毒性以及经济适用性方面在田间水平上进行应用。