Hänsch Robert, Mendel Ralf R
Department of Plant Biology, Technical University of Braunschweig, Humboldtstrasse 1, 38106, Braunschweig, Germany.
Photosynth Res. 2005 Dec;86(3):337-43. doi: 10.1007/s11120-005-5221-x. Epub 2005 Nov 12.
For a long time, occurrence and nature of sulfite oxidase activity in higher plants were controversially discussed. During primary sulfate assimilation in the chloroplast, sulfate is reduced via sulfite to organic sulfide, which is essential for cysteine biosynthesis. However, it has also been reported that sulfite can be oxidized back to sulfate, e.g. when plants were subjected to SO2 gas. Recently, work from our laboratory has identified the sulfite oxidase as the fourth member of molybdenum-enzymes in plants. Here we discuss how nature separates the two counteracting pathways--sulfate assimilation and sulfite detoxification--into two different cell organelles and we will also discuss how these two processes are coregulated.
长期以来，高等植物中亚硫酸盐氧化酶活性的存在及其性质一直存在争议。在叶绿体中进行的初级硫酸盐同化过程中，硫酸盐通过亚硫酸盐被还原为有机硫化物，这对于半胱氨酸的生物合成至关重要。然而，也有报道称亚硫酸盐可以被氧化回硫酸盐，例如当植物暴露于二氧化硫气体中时。最近，我们实验室的研究确定了亚硫酸盐氧化酶是植物中钼酶的第四个成员。在这里，我们将讨论自然界如何将硫酸盐同化和亚硫酸盐解毒这两个相互拮抗的途径分隔到两个不同的细胞器中，并且我们还将讨论这两个过程是如何协同调节的。
