Regulatory Interactions Between Sulfate and Nitrate Assimilation
Regulatory Interactions Between Sulfate and Nitrate Assimilation
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硫酸盐和硝酸盐同化之间的调节相互作用
DOI：
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发表时间：
1993
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通讯作者：
C. Brunold
中科院分区：
文献类型：
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作者：
C. Brunold
硫酸盐和硝酸盐以其最高度氧化的形式含有硫和氮，是许多植物满足其对这些元素需求的主要物质（Schiff 1983; Cram 1990; Oaks 1992）。因此，同化性硫酸盐和硝酸盐还原对于氨基酸的合成是必需的，所述氨基酸包括含硫氨基酸如半胱氨酸和甲硫氨酸，其中硫和氮都以还原形式存在。氨基酸的主要部分用于蛋白质合成。因此，植物中的S/N比通常约为1/20（Dijkshoorn &货车Wijk 1967），反映了这些元素在蛋白质中的比例。只有在硫以硫酸盐或植物次生产物的形式积累的物种中，这一比率才明显较高（Cram 1990; Ernst 1990）。植物似乎具有协调同化硫酸盐和硝酸盐还原的机制，使得适当比例的含硫氨基酸和其他氨基酸可用于蛋白质合成。本文综述了在同化水平上的这些相互调节机制，但NO3-和SO2吸收的调节对于协调两种同化途径可能至少同样重要（Saccomani & Ferrari 1989; Cram 1990;克拉克森等，本卷）。最近对同化硝酸盐（Solomonson & Barber 1990; Oaks 1992）和硫酸盐（Brunold 1990; Giovanelli 1990;施密特1992）的减少进行了综述。因此，这里只讨论这两种途径的各个方面，这些方面构成了审查它们之间的监管相互作用的基础。
Sulfate and nitrate, which contain sulfur and nitrogen in their most highly oxidized form, are the dominant species available to many plants for covering their needs for these elements (Schiff 1983; Cram 1990; Oaks 1992). Assimilatory sulfate and nitrate reduction are therefore necessary for the synthesis of amino acids including sulfur containing amino acids like cysteine and methionine, in which both sulfur and nitrogen are present in reduced form. The dominant portion of the amino acids is used for protein synthesis. Therefore, the S/N ratio in plants is usually about 1/20 (Dijkshoorn & van Wijk 1967) reflecting the proportion of these elements in proteins. Only in species where sulfur is accumulated in the form of sulfate or of secondary plant products is the ratio significantly higher (Cram 1990; Ernst 1990). Plants appear to possess mechanisms to coordinate assimilatory sulfate and nitrate reduction so that the appropriate proportions of both sulfur containing and other amino acids are available for protein synthesis. This review focuses on these reciprocal regulatory mechanisms at the level of assimilation, hut the regulation of the uptake of NO3- and SO2 may be at least as important for coordinating both assimilatory pathways (Saccomani & Ferrari 1989; Cram 1990; Clarkson et al., this volume). Assimilatory nitrate (Solomonson & Barber 1990; Oaks 1992) and sulfate (Brunold 1990; Giovanelli 1990; Schmidt 1992) reduction have been reviewed very recently. Therefore, only aspects of both pathways are discussed here which form the basis for reviewing regulatory interactions between them.