Why are higher plants green? Evolution of the higher plant photosynthetic pigment complement
Why are higher plants green? Evolution of the higher plant photosynthetic pigment complement
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DOI：
10.1046/j.1365-3040.2000.00563.x
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发表时间：
2000-06-01
影响因子：
7.3
通讯作者：
Nishio, JN
中科院分区：
文献类型：
--
作者：
Nishio, JN
高等植物是绿色的生理原因尚不清楚。其他光合生物利用能强烈吸收绿光的色素；因此，一定有自然力量“选择”了高等植物中的光合色素。根据先前发表的数据和我们最近关于叶片中绿光和光合作用的发现（Sun等人），描述了源自绿藻祖先的高等植物的主要光合色素的特定功能作用。叶绿素a和叶绿素b的特殊吸收特性似乎在高等植物中执行两种相互矛盾但又必要的功能。首先，叶绿素a和叶绿素b在非饱和条件下吸收光以最大限度地利用光，这一功能已被充分了解。其次，当吸收的光以热的形式散失时，它们可以在过饱和的光条件下充当保护色素。在这样的条件下，很大一部分光也可以被有效利用，特别是在叶子的底部，主要由绿光照射而不被下调。第二个功能可能是选择力，它产生了极其成功的陆生植物，从绿藻进化而来。
The physiological reason that higher plants are green is unknown. Other photosynthetic organisms utilize pigments that strongly absorb green light; therefore, there must have been natural forces that 'selected' the photosynthetic pigments found in higher plants. Based on previously published data and our recent findings about green light and photosynthesis within leaves (Sun et al,), a specific functional role is described for the primary photosynthetic pigments of higher plants, that were derived from green algal progenitors. The particular absorptive characteristics of chlorophylls a and b appear to perform two contradictory, but necessary functions in higher plants. Firstly, chlorophylls a and b absorb light for maximum utilization under non-saturating conditions, a function that is well understood. Secondly, they can act as protective pigments under over-saturating light conditions, when absorbed light is dissipated as heat. Under such conditions, a significant portion of light can also be efficiently utilized, especially in the bottom portion of the leaf, that is mainly illuminated by green light and not down-regulated, The second function may have been the selective force that gave rise to the extremely successful terrestrial plants, that evolved from green algae.