Proteaceae from severely phosphorus-impoverished soils extensively replace phospholipids with galactolipids and sulfolipids during leaf development to achieve a high photosynthetic phosphorus-use-efficiency
Proteaceae from severely phosphorus-impoverished soils extensively replace phospholipids with galactolipids and sulfolipids during leaf development to achieve a high photosynthetic phosphorus-use-efficiency
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DOI：
10.1111/j.1469-8137.2012.04285.x
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发表时间：
2012-12-01
期刊：
影响因子：
9.4
通讯作者：
Turner, Benjamin L.
中科院分区：
文献类型：
--
作者：
Lambers, Hans;Cawthray, Gregory R.;Turner, Benjamin L.
澳大利亚西南部的Proteaceae物种分布在严重磷(P)贫瘠的土壤上。它们的叶片磷浓度很低，但光合作用速率相对较快，因此表现出极高的光合磷利用效率(PPUE)。尽管支撑其高PPUE的机制尚不清楚，但一种可能性是，这些物种在叶片发育过程中可能能够在不影响光合作用的情况下用非磷脂取代磷脂。对于6个Proteaceae物种，我们测量了土壤和叶片中P的浓度以及幼叶、展开叶和成熟叶的光合作用速率。我们还评估了在幼叶和成熟叶中对半乳脂、硫脂和磷脂的投资，并将这些结果与在磷充足和缺磷条件下生长的拟南芥的结果进行了比较。在所有蛋白质科植物中，磷脂水平在叶片发育过程中显著下降，而半乳脂和硫脂水平强烈上升。光合作用速率从幼叶到成熟叶逐渐增加。这表明，在叶片发育过程中，这些物种广泛地用非磷脂取代磷脂，而不影响光合作用。我们的结果清楚地表明，与非磷脂相比，磷脂的投入较低，这部分解释了在适应磷贫瘠的土壤中，蛋白质科植物单位叶磷的高光合作用速率。
Proteaceae species in south-western Australia occur on severely phosphorus (P)-impoverished soils. They have very low leaf P concentrations, but relatively fast rates of photosynthesis, thus exhibiting extremely high photosynthetic phosphorus-use-efficiency (PPUE). Although the mechanisms underpinning their high PPUE remain unknown, one possibility is that these species may be able to replace phospholipids with nonphospholipids during leaf development, without compromising photosynthesis.For six Proteaceae species, we measured soil and leaf P concentrations and rates of photosynthesis of both young expanding and mature leaves. We also assessed the investment in galactolipids, sulfolipids and phospholipids in young and mature leaves, and compared these results with those on Arabidopsis thaliana, grown under both P-sufficient and P-deficient conditions.In all Proteaceae species, phospholipid levels strongly decreased during leaf development, whereas those of galactolipids and sulfolipids strongly increased. Photosynthetic rates increased from young to mature leaves. This shows that these species extensively replace phospholipids with nonphospholipids during leaf development, without compromising photosynthesis. A considerably less pronounced shift was observed in A. thaliana.Our results clearly show that a low investment in phospholipids, relative to nonphospholipids, offers a partial explanation for a high photosynthetic rate per unit leaf P in Proteaceae adapted to P-impoverished soils.