Light-dependent maintenance of hydraulic function in mangrove branches: do xylary chloroplasts play a role in embolism repair?
Article first published online: 17 MAY 2012
© 2012 The Authors. New Phytologist © 2012 New Phytologist Trust
Volume 195, Issue 1, pages 40–46, July 2012
How to Cite
Schmitz, N., Egerton, J. J. G., Lovelock, C. E. and Ball, M. C. (2012), Light-dependent maintenance of hydraulic function in mangrove branches: do xylary chloroplasts play a role in embolism repair?. New Phytologist, 195: 40–46. doi: 10.1111/j.1469-8137.2012.04187.x
- Issue published online: 24 MAY 2012
- Article first published online: 17 MAY 2012
- Received: 21 February 2012, Accepted: 22 April 2012
- branch photosynthesis;
- embolism repair;
- hydraulic conductivity;
- xylary chloroplasts
- •To clarify the role of branch photosynthesis in tree functioning, the presence and function of chloroplasts in branch xylem tissue were studied in a diverse range of mangrove species growing in Australia.
- •The presence of xylary chloroplasts was observed via chlorophyll fluorescence of transverse sections. Paired, attached branches were selected to study the effects of covering branches with aluminium foil on the gas exchange characteristics of leaves and the hydraulic conductivity of branches.
- •Xylary chloroplasts occurred in all species, but were differently distributed among living cell types in the xylem. Covering stems altered the gas exchange characteristics of leaves, such that water-use efficiency was greater in exposed leaves of covered than of uncovered branches.
- •Leaf-specific hydraulic conductivity of stems was lower in covered than in uncovered branches, implicating stem photosynthesis in the maintenance of hydraulic function. Given their proximity to xylem vessels, we suggest that xylary chloroplasts may play a role in light-dependent repair of embolized xylem vessels.