Effects of growth light and nitrogen nutrition on the organization of the photosynthetic apparatus in leaves of a C4 plant, Amaranthus cruentus.
Effects of growth light and nitrogen nutrition on the organization of the photosynthetic apparatus in leaves of a C4 plant, Amaranthus cruentus.
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DOI：
10.1111/j.1365-3040.2005.01453.x
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发表时间：
2006-04
期刊：
影响因子：
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通讯作者：
Youshi Tazoe;K. Noguchi;I. Terashima
中科院分区：
文献类型：
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作者：
Youshi Tazoe;K. Noguchi;I. Terashima
研究了籽粒苋C4光合特性。（NAD-苹果酸酶（ME）亚型，双子叶植物）生长在不同的光和氮（N）条件下，从N投资到他们的光合成分的观点。在低光（LL）叶片，叶绿素含量/叶面积比高光（HL）叶片，叶绿素a/b降低。这表明LL叶片将更多的N投入到其捕光系统中。然而，这N投资没有贡献的增加在入射光子通量密度（PFD）的基础上（齐）在LL叶片的光合作用的量子产率。高氮叶片中氮素向核酮糖1，5-二磷酸羧化酶加氧酶（Rubisco）的分配显著高于其它叶片。另一方面，N分配到C4酶[磷酸烯醇式丙酮酸羧化酶（PEPC）和丙酮酸Pi二激酶（PPDK）]不受生长条件的影响。最大光合速率（Pmax）每Rubisco含量是相似的，无论生长光处理。叶片干物质碳同位素比值（δ 13 C）LL比HL更负（LL = -19.3%/100，HL = -16.0%/100），且与叶片N无关。HL-HN叶片的叶脉密度最高，叶片厚度不受生长光处理的影响。根据这些结果，我们得出结论：A. cruentus叶片不能有效地适应低生长光。
Properties of C4 photosynthesis were examined in Amaranthus cruentus L. (NAD-malic enzyme (ME) subtype, dicot) grown under different light and nitrogen (N) conditions, from the viewpoint of N investment into their photosynthetic components. In low-light (LL) leaves, chlorophyll content per leaf area was greater and chlorophyll alb ratio was lower than in high-light (HL) leaves. These indicate that LL leaves invest more N into their light-harvesting systems. However, this N investment did not contribute to the increase in the quantum yield of photosynthesis on the incident photon flux density (PFD) basis (Qi) in LL leaves. N allocation to ribulose 1,5-bisphosphate carboxylasel oxygenase (Rubisco) was significantly higher in HL-high N (HN) leaves than in other leaves. On the other hand, N allocation to C4 enzymes [phosphoenolpyruvate carboxylase (PEPC) and pyruvate Pi dikinase (PPDK)] was unaffected by the growth conditions. Maximum photosynthetic rates (Pmax) per Rubisco content were similar irrespective of the growth light treatments. Carbon isotope ratios (delta13 C) in the leaf dry matter were more negative in LL leaves than in HL leaves (LL = -19.3% per hundred, HL = -16.0% per hundred) and independent of leaf N. Vein density was highest in HL-HN leaves, and leaf thickness was unaffected by the growth light treatments. From these results, we conclude that A. cruentus leaves would not acclimate efficiently to low growth light.