Dipartimento di Biologia, Università di Napoli "Federico II", Complesso Universitario di Monte Sant'Angelo, Via Cinthia, Napoli 80126, Italy.
Department of Plant Physiology, Faculty of Sciences, University of Granada, 18071 Granada, Spain.
Plant Sci. 2022 Jun;319:111259. doi: 10.1016/j.plantsci.2022.111259. Epub 2022 Mar 17.
An adequate availability of Zinc (Zn) is crucial for plant growth and development given the essentiality of this element. Thus, both Zn deficiency and Zn toxicity can limit crop yields. In plants, the responses to Zn imbalances involve important physiological aspects such as reactive oxygen species (ROS) accumulation, phytohormone balance, tricarboxylic acid cycle (TCA) metabolism, and organic acids (OAs) accumulation. However, a way to improve tolerance to stresses such as those produced by nutritional imbalances is the application of beneficial elements such as silicon (Si). In this study, we grew barley plants in hydroponics under Zn deficiency and toxicity conditions, applying Si in the form of CaSiO in order to assess its effectiveness against Zn imbalances. Parameters related to plant growth, oxidative stress, TCA enzyme activities, phytohormones and OAs accumulation were analyzed. Both Zn deficiency and toxicity reduced leaf biomass, increased ROS accumulation, and affected phytohormone and OAs concentrations and TCA enzyme activities. CaSiO treatment was effective in counteracting these effects enhancing Zn accumulation under Zn deficient conditions and limiting its accumulation under toxic conditions. In addition, this treatment decreased ROS levels, and improved ascorbate/glutathione and phytohormonal responses, citrate synthase activity, and malate/oxalate ratio. Therefore, this study enhanced the notion of the efficacy of CaSiO in improving tolerance to Zn imbalances.
由于锌（Zn）是植物生长和发育所必需的，因此其充足的供应对植物至关重要。因此，锌缺乏和锌毒性都会限制作物产量。在植物中，对锌失衡的反应涉及到重要的生理方面，如活性氧（ROS）积累、植物激素平衡、三羧酸（TCA）循环代谢和有机酸（OAs）积累。然而，提高对营养失衡等胁迫的耐受性的一种方法是应用有益元素，如硅（Si）。在这项研究中，我们在水培条件下用 CaSiO3 的形式向大麦植株施加硅，以评估其对锌失衡的有效性。分析了与植物生长、氧化应激、TCA 酶活性、植物激素和有机酸积累相关的参数。锌缺乏和毒性都降低了叶片生物量，增加了 ROS 积累，并影响了植物激素和有机酸浓度以及 TCA 酶活性。CaSiO3 处理有效地抵消了这些影响，在缺锌条件下促进了 Zn 的积累，在毒性条件下限制了其积累。此外，这种处理降低了 ROS 水平，改善了抗坏血酸/谷胱甘肽和植物激素反应、柠檬酸合酶活性以及苹果酸/草酸比。因此，这项研究增强了 CaSiO3 提高对锌失衡的耐受性的功效的概念。
