More Details of Photosynthesis Coming to Light

Photosynthesis, the light-harvesting capability of plants, was a black box 30 years ago, but more and more details have been elucidated by advanced probing techniques.  In the March 18 issue of Nature,¹, a team of Chinese scientists determined the X-ray structure of a principal component acts like a light-harvesting antenna.  The structure utilizes special molecules that not only gather the energy of light, but also get rid of excess energy that could damage the plant.  They write, “Four carotenoid-binding sites per monomer have been observed.  The xanthophyll-cycle carotenoid at the monomer-monomer interface may be involved in the non-radiative dissipation of excessive energy, one of the photoprotective strategies that have evolved in plants.”

¹Liu et al., “Crystal structure of spinach major light-harvesting complex at 2.72 � resolution,” Nature 428, 287 – 292 (18 March 2004); doi:10.1038/nature02373.

Nice observation, but another example of the Darwinian bad habit of assuming what ought to be proved.  Plants don’t evolve protective strategies.  That requires intelligence.