Low light intensity is always the important factor that influences the growth and development of Brassica pekinesis during winter seasons. We have found out that appropriate ammonium/nitrate ratio mitigated low light intensity in the previous study. In the present study, the nitrogen metabolism and proteomic responses of Brassica pekinensis to light intensities and ammonium/nitrate were further investigated to find out the mitigation mechanism. The activities of nitrate reductase (NR) and glutamine synthetase (GS) and the relative expression of GS1 as well as the content of nitric oxide (NO) were significantly higher in the NH4+:NO3− (15:85) treatment than in the NH4+:NO3− (0:100) treatment under normal light intensity. However, under low light intensity condition, the activities of NR and GS and relative expression of NR as well as the NO level in seedlings fertilized with NH4+:NO3− (10:90) were significantly higher compared with those fertilized with NH4+:NO3− (0:100). In addition, we found thirty-six protein spots, which exhibited significant changes in abundance using similarity searches across the uniprot database of Brassica. The proteins identified were classified into ten functional groups including photosynthesis, carbon and energy metabolism, stress/defense, protein folding, and modification and degradation response. We concluded that appropriate ammonium nitrate ratio improves the tolerance of mini Chinese cabbage seedlings to low light intensity by regulating the nitrogen metabolism and expression levels of some key proteins.

中文翻译：

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适当的铵盐/硝酸盐通过调节氮代谢和关键蛋白质的表达水平减轻白菜的低光胁迫

冬季光照强度低一直是影响白菜生长发育的重要因素。在之前的研究中，我们发现适当的铵盐/硝酸盐比率可以减轻低光强度。在本研究中，进一步研究了白菜对光强度和铵盐/硝酸盐的氮代谢和蛋白质组学响应，以找出缓解机制。NH4+:NO3−(15:85)处理中硝酸还原酶(NR)和谷氨酰胺合成酶(GS)的活性、GS1的相对表达量和一氧化氮(NO)含量均显着高于NH4+处理:NO3− (0:100) 在正常光强度下处理。但在低光照条件下，与NH4+:NO3− (0:100) 施肥的幼苗相比，NH4+:NO3− (10:90) 的幼苗中NR 和GS 的活性和NR 的相对表达以及NO 水平显着升高。此外，我们发现了 36 个蛋白质点，它们在芸苔属的 uniprot 数据库中使用相似性搜索表现出显着的丰度变化。鉴定出的蛋白质分为十个功能组，包括光合作用、碳和能量代谢、应激/防御、蛋白质折叠以及修饰和降解反应。我们得出结论，适当的硝酸铵比例通过调节氮代谢和一些关键蛋白质的表达水平来提高小白菜幼苗对弱光的耐受性。90) 显着高于那些用 NH4+:NO3− (0:100) 施肥的人。此外，我们发现了 36 个蛋白质点，它们在芸苔属的 uniprot 数据库中使用相似性搜索表现出显着的丰度变化。鉴定出的蛋白质分为十个功能组，包括光合作用、碳和能量代谢、应激/防御、蛋白质折叠以及修饰和降解反应。我们得出结论，适当的硝酸铵比例通过调节氮代谢和一些关键蛋白质的表达水平来提高小白菜幼苗对弱光的耐受性。90) 显着高于那些用 NH4+:NO3− (0:100) 施肥的人。此外，我们发现了 36 个蛋白质点，它们在芸苔属的 uniprot 数据库中使用相似性搜索表现出显着的丰度变化。鉴定出的蛋白质分为十个功能组，包括光合作用、碳和能量代谢、应激/防御、蛋白质折叠以及修饰和降解反应。我们得出结论，适当的硝酸铵比例通过调节氮代谢和一些关键蛋白质的表达水平来提高小白菜幼苗对弱光的耐受性。使用跨芸苔属uniprot数据库的相似性搜索表现出丰度的显着变化。鉴定出的蛋白质分为十个功能组，包括光合作用、碳和能量代谢、应激/防御、蛋白质折叠以及修饰和降解反应。我们得出结论，适当的硝酸铵比例通过调节氮代谢和一些关键蛋白质的表达水平来提高小白菜幼苗对弱光的耐受性。使用跨芸苔属uniprot数据库的相似性搜索表现出丰度的显着变化。鉴定出的蛋白质分为十个功能组，包括光合作用、碳和能量代谢、应激/防御、蛋白质折叠以及修饰和降解反应。我们得出结论，适当的硝酸铵比例通过调节氮代谢和一些关键蛋白质的表达水平来提高小白菜幼苗对弱光的耐受性。