Abstract
How evergreen species store and protect chlorophyll during exposure to high light in winter remains unexplained. This study reveals that the evergreen snow gum (Eucalyptus pauciflora Sieb. ex Spreng.) stores and protects its chlorophylls by forming special complexes that are unique to the winter-acclimated state. Our in vivo spectral and kinetic characterizations reveal a prominent component of the chlorophyll fluorescence spectrum around 715 nm at 77 K. This band coincides structurally with a loss of chlorophyll and an increase in energy-dissipating carotenoids. Functionally, the band coincides with an increased capacity to dissipate excess light energy, absorbed by the chlorophylls, as heat without intrathylakoid acidification. The increased heat dissipation helps protect the chlorophylls from photo-oxidative bleaching and thereby facilitates rapid recovery of photosynthesis in spring.
| Original language | English |
|---|---|
| Pages (from-to) | 11098-11101 |
| Number of pages | 4 |
| Journal | Proceedings of the National Academy of Sciences of the United States of America |
| Volume | 97 |
| Issue number | 20 |
| DOIs | |
| Publication status | Published - 26 Sept 2000 |