Irradiance and phenotype:: comparative eco-development of sun and shade leaves in relation to photosynthetic CO2 diffusion
Irradiance and phenotype:: comparative eco-development of sun and shade leaves in relation to photosynthetic CO2 diffusion
复制标题
DOI：
10.1093/jxb/erj014
复制
发表时间：
2006-01-01
影响因子：
6.9
通讯作者：
Yano, S
中科院分区：
文献类型：
--
作者：
Terashima, I;Hanba, YT;Yano, S
本文从两个方面探讨了阳生叶比阴生叶厚、光合速率高的问题。第一个试图回答这个问题：为什么阳光下的叶子比阴影下的叶子厚？要做到这一点，CO2扩散内的叶首先检查。由于Rubisco对CO2的亲和力较低，1，5-二磷酸核酮糖的羧化被O-2竞争性抑制，而1，5-二磷酸核酮糖的氧化导致耗能的光呼吸，因此维持叶绿体内尽可能高的CO2浓度对C-3植物至关重要。由于从细胞间隙到叶绿体基质的CO2扩散的内部传导是有限的并且相对较小，C-3叶应该具有足够的被叶绿体占据的叶肉表面以确保用于CO2溶解和运输的区域。这就解释了为什么太阳的叶子比较厚。第二种方法是机械的或“如何导向”的。讨论了阳生叶厚于阴生叶的机理，特别是成熟叶向叶原基的长距离信号传导，诱导栅栏组织细胞的平周分裂。为了增加叶肉表面积，叶片可以更厚或具有更小的细胞。细胞大小的问题进行了讨论，了解叶厚度的可塑性。
The subject of this paper, sun leaves are thicker and show higher photosynthetic rates than the shade leaves, is approached in two ways. The first seeks to answer the question: why are sun leaves thicker than shade leaves? To do this, CO2 diffusion within a leaf is examined first. Because affinity of Rubisco for CO2 is low, the carboxylation of ribulose 1,5-bisphosphate is competitively inhibited by O-2, and the oxygenation of ribulose 1,5-bisphosphate leads to energy-consuming photorespiration, it is essential for C-3 plants to maintain the CO2 concentration in the chloroplast as high as possible. Since the internal conductance for CO2 diffusion from the intercellular space to the chloroplast stroma is finite and relatively small, C-3 leaves should have sufficient mesophyll surfaces occupied by chloroplasts to secure the area for CO2 dissolution and transport. This explains why sun leaves are thicker. The second approach is mechanistic or 'how-oriented'. Mechanisms are discussed as to how sun leaves become thicker than shade leaves, in particular, the long-distance signal transduction from mature leaves to leaf primordia inducing the periclinal division of the palisade tissue cells. To increase the mesophyll surface area, the leaf can either be thicker or have smaller cells. Issues of cell size are discussed to understand plasticity in leaf thickness.