Photosynthesis is strongly reduced by antisense suppression of chloroplastic cytochrome bf complex in transgenic tobacco
Photosynthesis is strongly reduced by antisense suppression of chloroplastic cytochrome bf complex in transgenic tobacco
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DOI：
10.1071/pp97164
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发表时间：
1998-01-01
期刊：
影响因子：
--
通讯作者：
Badger, MR
中科院分区：
文献类型：
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作者：
Price, GD;von Caemmerer, S;Badger, MR
我们使用了转基因烟草(Nicitiana tabacum L.cv.W38)针对叶绿体bf复合体的Rieske FeS蛋白转录本表达反义基因的植物，以检测叶绿体Rieske FeS含量降低对叶片气体交换和光合代谢物库的影响。分析了叶绿体Rieske FES蛋白含量为野生型的5%到80%的植株。在叶面积的基础上，CO2同化速率随着Rieske FeS含量的减少而线性下降。与光合作用相反，气孔导度除野生型Rieske FeS含量低于10%外，其余均未发生变化。Rieske FeS含量与细胞色素f含量密切相关，表明Rieske FeS含量的降低导致细胞色素bf复合体的其他成分也有类似的减少。虽然较低的Rieske FeS含量与叶绿素含量、ATP增量亚单位和核酮糖二磷酸羧基加氧酶(Rubisco)含量的下降有关，但这些下降幅度远远小于细胞色素bf含量的下降。随着Rieske FeS含量的降低，叶绿素a/b比值略有下降。在环境CO2和强光下，较低的CO2同化率与二磷酸核酮糖(RuBP)和3-磷酸甘油酸(PGA)的显著下降有关。在Rieske FeS含量低于野生型的20%的植株中，Rubisco氨基甲酰化程度下降到40%-50%。我们的结论是，在高光下，叶绿体Rieske FES蛋白含量的减少通过限制电子传递和通过影响体内Rubisco活性而降低RuBP的再生速度，从而抑制CO2同化速率。
We have used transgenic tobacco (Nicotiana tabacum L. cv. W38) plants expressing an antisense gene directed against the transcript of the Rieske FeS protein of the chloroplast bf complex to examine the effect a reduction in chloroplast Rieske FeS content on leaf gas exchange and photosynthetic metabolite pools. Plants with chloroplast Rieske FeS protein content ranging from 5 to 80% of wild-type were analysed. CO2 assimilation rate declined linearly with the reduction in Rieske FeS content when expressed on a leaf area basis. In contrast to photosynthesis, there was no change in stomatal conductance except for plants with less than 10% of wild-type Rieske FeS content. There was a close correlation between Rieske FeS content and cytochrome f content, showing that the reduction in Rieske FeS content lead to a similar reduction in other components of the cytochrome bf complex. While lower Rieske FeS content was associated with declines in chlorophyll content, ATP delta subunit and ribulosebisphosphate carboxylase-oxygenase (Rubisco) contents, these declines were considerably smaller than the reduction in cytochrome bf content. As Rieske FeS content was reduced, there was a slight lowering of the chlorophyll a/b ratio. Lower CO2 assimilation rates at ambient CO2 and high light were associated with dramatic reductions in ribulose bisphosphate (RuBP) and modest declines in 3-phosphoglycerate (PGA). Rubisco carbamylation declined to 40-50% in plants with Rieske FeS content lower than 20% of wild-type. We conclude that, at high light, a reduction in chloroplast Rieske FeS protein content leads to inhibition of CO2 assimilation rate via reductions in the rate of RuBP regeneration caused by a restriction in electron transport and via effects on in vivo Rubisco activity.