Development and Collaborative Innovation Center of Plant Germplasm Resources, Shanghai Engineering Research Center of Plant Germplasm Resources, College of Life and Environment Science, Shanghai Normal University, Shanghai 200234, China.
Molecules. 2018 May 27;23(6):1286. doi: 10.3390/molecules23061286.
Spinach ( L.) is one of most important leafy vegetables because of its high nutritional value and high oxalate content, which can be toxic with negative effects on human nutrition. Ammonium and nitrate can effectively regulate oxalate accumulation, although the mechanisms underlying the oxalate biosynthesis and regulation are still undetermined in plants. In the present study, we identified 25 putative genes that are involved in the oxalate biosynthetic and degradation pathway, before analyzing the oxalate content and the expression levels of the corresponding proteins under normal growth conditions, with or without ammonium and nitrate treatments, using high and low oxalate-accumulated spinach genotypes. The two cultivars exhibited different profiles of total oxalate and soluble oxalate accumulation. The high oxalate concentrations in spinach were as a result of the high transcription levels of the genes that are involved in oxalate biosynthesis under normal growth conditions, such as , , three , , , , and . The results revealed that the ammonium and nitrate were able to control the oxalate content in leaves, possibly because of the different transcription levels of the genes. The oxalate content is regulated by complex regulatory mechanisms and is varied in the different varieties of spinach. The results from this research may be used to assist the investigation of the mechanism of oxalate regulation and breeding for reduced oxalate content in spinach.
菠菜（ L.）是最重要的叶菜之一，因为其具有高营养价值和高草酸盐含量，草酸盐对人体营养有负面影响，可能有毒。铵和硝酸盐可以有效地调节草酸盐的积累，尽管植物中草酸盐生物合成和调节的机制仍未确定。在本研究中，我们鉴定了 25 个可能参与草酸盐生物合成和降解途径的基因，然后在正常生长条件下，分析了相应蛋白的草酸盐含量和表达水平，同时进行了高、低草酸盐积累菠菜基因型的铵和硝酸盐处理。两个品种表现出不同的总草酸盐和可溶性草酸盐积累特征。菠菜中的高草酸盐浓度是由于正常生长条件下参与草酸盐生物合成的基因的转录水平较高，例如、、三个、、、、和。结果表明，铵和硝酸盐能够控制叶片中的草酸盐含量，可能是由于基因的转录水平不同。草酸盐含量受复杂的调控机制调节，在不同品种的菠菜中有所差异。本研究的结果可用于辅助研究草酸盐调控机制，并为培育低草酸盐含量的菠菜提供帮助。
