Nejamkin Andrés, Del Castello Fiorella, Lamattina Lorenzo, Correa-Aragunde Natalia, Foresi Noelia
Instituto de Investigaciones Biológicas-CONICET, Universidad Nacional de Mar del Plata, Mar del Plata, Argentina.
Antioxid Redox Signal. 2025 Feb;42(4-6):280-291. doi: 10.1089/ars.2022.0210. Epub 2023 Sep 29.
Nitrogen (N) is a necessary nutrient for plant development and seed production, with nitrate (NO) serving as the primary source of N in soils. Although several molecular players in plant responses to NO signaling were unraveled, it is still a complex process with gaps that require further investigation. The aim of our study is to analyze the role of nitric oxide (NO) in the primary nitrate response (PNR). Using a combination of genetic and pharmacological approaches, we demonstrate that NO is required for the expression of the NO-regulated genes nitrate reductase 1 (), nitrite reductase (), and nitrate transporters (nitrate transporter 1.1 [] and nitrate transporter 2.1 []) in Arabidopsis. The PNR is impaired in the Arabidopsis mutant , defective in NO production. Our results also show that (), involved in NO homeostasis, is rapidly induced during PNR in wild type (wt) but not in the mutants of the nitrate transceptor NTR1.1 and the transcription factor nodule inception-like protein 7 (NLP7), suggesting that the NRT1.1-NLP7 cascade modulates gene expression. Biotin switch experiments demonstrate that NLP7, the PNR-master regulator, is S-nitrosated . Depletion of NO during PNR intensifies the decrease in reactive oxygen species levels and the rise of catalase (CAT) and ascorbate peroxidase (APX) enzyme activity. NO, a by-product of NO metabolism and a well-characterized signal molecule in plants, is an important player in the PNR.
氮（N）是植物生长发育和种子生产所必需的营养元素，硝酸盐（NO₃⁻）是土壤中氮的主要来源。尽管已经揭示了植物对NO₃⁻信号响应中的几个分子参与者，但这仍然是一个复杂的过程，存在需要进一步研究的空白。我们研究的目的是分析一氧化氮（NO）在初级硝酸盐响应（PNR）中的作用。通过结合遗传和药理学方法，我们证明在拟南芥中，NO是NO₃⁻调节基因硝酸还原酶1（NIA1）、亚硝酸还原酶（NIR）和硝酸盐转运蛋白（硝酸盐转运蛋白1.1 [NRT1.1]和硝酸盐转运蛋白2.1 [NRT2.1]）表达所必需的。在拟南芥突变体中，PNR受损，该突变体在NO产生方面存在缺陷。我们的结果还表明，参与NO稳态的NIA1在野生型（wt）的PNR过程中迅速被诱导，但在硝酸盐转运受体NTR1.1和转录因子结节起始样蛋白7（NLP7）的突变体中则没有，这表明NRT1.1-NLP7级联调节NIA1基因表达。生物素转换实验表明，PNR的主要调节因子NLP7被S-亚硝基化。在PNR过程中NO的消耗加剧了活性氧水平的降低以及过氧化氢酶（CAT）和抗坏血酸过氧化物酶（APX）酶活性的升高。NO，作为NO代谢的副产物以及植物中一个特征明确的信号分子，是PNR中的一个重要参与者。
