Weigel Martin, Varotto Claudio, Pesaresi Paolo, Finazzi Giovanni, Rappaport Fabrice, Salamini Francesco, Leister Dario
Abteilung für Pflanzenzüchtung und Ertragsphysiologie, Max-Planck-Institut für Züchtungsforschung, Carl-von-Linné-Weg 10, D-50829 Köln, Germany.
J Biol Chem. 2003 Aug 15;278(33):31286-9. doi: 10.1074/jbc.M302876200. Epub 2003 May 28.
Plastocyanin is a soluble copper-containing protein present in the thylakoid lumen, which transfers electrons to photosystem I. In the chloroplast of the flowering plant Arabidopsis thaliana, a cytochrome c6-like protein is present, which was recently suggested to function as an alternative electron carrier to plastocyanin. We show that Arabidopsis plants mutated in both of the two plastocyanin-coding genes and with a functional cytochrome c6 cannot grow photoautotrophically because of a complete block in light-driven electron transport. Even increased dosage of the gene encoding the cytochrome c6-like protein cannot complement the double mutant phenotype. This demonstrates that in Arabidopsis only plastocyanin can donate electrons to photosystem I in vivo.
质体蓝素是一种存在于类囊体腔中的可溶性含铜蛋白，它将电子传递给光系统I。在开花植物拟南芥的叶绿体中，存在一种细胞色素c6样蛋白，最近有人提出它可作为质体蓝素的替代电子载体发挥作用。我们发现，两个质体蓝素编码基因均发生突变且具有功能性细胞色素c6的拟南芥植株不能进行光合自养生长，因为光驱动电子传递完全受阻。即使增加编码细胞色素c6样蛋白的基因剂量也不能弥补双突变体表型。这表明在拟南芥中，体内只有质体蓝素能向光系统I提供电子。
