Temperature response of mesophyll conductance in cultivated and wild Oryza species with contrasting mesophyll cell wall thickness
Temperature response of mesophyll conductance in cultivated and wild Oryza species with contrasting mesophyll cell wall thickness
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DOI：
10.1111/j.1365-3040.2011.02398.x
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发表时间：
2011-11-01
影响因子：
7.3
通讯作者：
Atwell, Brian J.
中科院分区：
文献类型：
--
作者：
Scafaro, Andrew P.;Von Caemmerer, Susanne;Atwell, Brian J.
光合作用能力的一个关键组成部分是二氧化碳从细胞间隙到叶绿体基质中二氧化碳固定部位的电导，称为叶肉电导(g(M))。叶片解剖结构已被认为是决定g(M)的重要因素。关于g(M)的温度响应的研究很少，也没有人研究过叶片解剖学的含义。因此，我们将一个栽培品种与澳大利亚炎热的北部大草原特有的两个野生水稻近缘，即子午野生稻和澳大利亚野生稻进行了比较。这三个物种都有相似的叶片解剖特性，除了野生近缘植物的叶肉细胞壁明显比栽培稻厚得多。野生稻较厚的叶肉细胞壁可能是导致g(M)下降的原因，这与与水稻相比，更多的二氧化碳吸收到叶绿体(C-i-C-c)有关。温度越高，叶肉电导率越高，而CO2同化速率在20-40℃之间相对稳定。因此，三种植物的C-I-C-C均随温度升高而降低。
A critical component of photosynthetic capacity is the conductance of CO2 from intercellular airspaces to the sites of CO2 fixation in the stroma of chloroplasts, termed mesophyll conductance (g(m)). Leaf anatomy has been identified as an important determinant of g(m). There are few studies of the temperature response of g(m) and none has examined the implications of leaf anatomy. Hence, we compared a cultivar of Oryza sativa with two wild Oryza relatives endemic to the hot northern savannah of Australia, namely Oryza meridionalis and Oryza australiensis. All three species had similar leaf anatomical properties, except that the wild relatives had significantly thicker mesophyll cell walls than O. sativa. Thicker mesophyll cell walls in the wild rice species are likely to have contributed to the reduction in g(m), which was associated with a greater drawdown of CO2 into chloroplasts (C-i-C-c) compared with O. sativa. Mesophyll conductance increased at higher temperatures, whereas the rate of CO2 assimilation was relatively stable between 20 and 40 degrees C. Consequently, C-i-C-c decreased for all three species as temperature increased.