首页 | 本学科首页   官方微博 | 高级检索  
     检索      


Ecology and ecophysiology of tree stems: corticular and wood photosynthesis
Authors:Pfanz H  Aschan G  Langenfeld-Heyser R  Wittmann C  Loose M
Institution:Institut für Angewandte Botanik, Universit?t Essen, Germany. hardy.pfanz@uni-essen.de
Abstract:Below the outer peridermal or rhytidomal layers, most stems of woody plants possess greenish tissues. These chlorophyll-containing tissues (the chlorenchymes) within the stems are able to use the stem internal CO2 and the light penetrating the rhytidome to photoassimilate and produce sugars and starch. Although net photosynthetic uptake of CO2 is rarely found, stem internal re-fixation of CO2 in young twigs and branches may compensate for 60-90% of the potential respiratory carbon loss. Isolated chlorenchymal tissues reveal rather high rates of net photosynthesis (being up to 75% of the respective rates for leaf photosynthesis). Corticular photosynthesis is thus thought to be an effective mechanism for recapturing respiratory carbon dioxide before it diffuses out of the stem. Furthermore, chloroplasts of the proper wood or pith fraction also take part in stem internal photosynthesis. Although there has been no strong experimental evidence until now, we suggest that the oxygen evolved during wood or pith photosynthesis may play a decisive role in avoiding/reducing stem internal anaerobiosis.
Keywords:
本文献已被 PubMed SpringerLink 等数据库收录!
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号