Machado Joana, Vasconcelos Marta W, Soares Cristiano, Fidalgo Fernanda, Heuvelink Ep, Carvalho Susana M P
GreenUPorto-Sustainable Agrifood Production Research Centre/Inov4Agro, DGAOT, Faculty of Sciences, University of Porto, Campus de Vairão, Rua da Agrária 747, 4485-646 Vairão, Portugal.
CBQF-Centro de Biotecnologia e Química Fina-Laboratório Associado, Escola Superior de Biotecnologia, Universidade Católica Portuguesa, Rua Diogo Botelho 1327, 4169-005 Porto, Portugal.
Antioxidants (Basel). 2023 Feb 4;12(2):375. doi: 10.3390/antiox12020375.
This study aims to perform a broad analysis of the antioxidant (AOX) responses of young tomato plants exposed to single and combined mild nitrogen (N) and water deficits through the evaluation of oxidative biomarkers, non-enzymatic and enzymatic AOX components. 'Micro-Tom' seedlings were subjected to four treatments: control (CTR; 100%N + 100%W), N deficit (N; 50%N), water deficit (W; 50%W), and combined deficits (N + W; 50%N + 50%W). An enhancement of several non-enzymatic and enzymatic components was found in plants subjected to N + W deficit, which presented higher anthocyanins accumulation (up to 103%) as well as higher levels of superoxide dismutase (SOD) transcripts at root level and of ascorbate peroxidase (APX) and catalase (CAT) transcripts at shoot level. This increase in the gene expression was also translated in augmented SOD (up to 202%), APX (up to 155%) and CAT (up to 108%) activity compared to CTR plants and the single deficits. Overall, tomato plants were able to employ defense strategies to cope with this combined deficit, as demonstrated by the higher total AOX capacity (up to 87%) compared to the single deficits, which contributed to the maintenance of their redox homeostasis, with unchanged values of lipid peroxidation and hydrogen peroxide compared with CTR plants.
本研究旨在通过评估氧化生物标志物、非酶促和酶促抗氧化成分，对暴露于单一和复合轻度氮（N）和水分亏缺的番茄幼苗的抗氧化（AOX）反应进行广泛分析。“微型番茄”幼苗接受了四种处理：对照（CTR；100%N + 100%W）、氮亏缺（N；50%N）、水分亏缺（W；50%W）和复合亏缺（N + W；50%N + 50%W）。在遭受N + W亏缺的植株中发现几种非酶促和酶促成分增强，其花青素积累更高（高达103%），根部超氧化物歧化酶（SOD）转录本以及地上部抗坏血酸过氧化物酶（APX）和过氧化氢酶（CAT）转录本水平更高。与对照植株和单一亏缺相比，这种基因表达的增加还转化为SOD（高达202%）、APX（高达155%）和CAT（高达108%）活性增强。总体而言，番茄植株能够采用防御策略来应对这种复合亏缺，与单一亏缺相比，其总AOX能力更高（高达87%），这有助于维持其氧化还原稳态，与对照植株相比，脂质过氧化和过氧化氢值未发生变化。
