Send to

Choose Destination
See comment in PubMed Commons below
Plant Physiol. 1968 Jun;43(6):845-52.

Seasonal Changes in the Distribution of Photo-assimilated C in Young Pine Plants.

Author information

Department of Biology, Queen's University, Kingston, Ontario, Canada.


Pinus strobus L. plants in their third year of growth were permitted to photoassimilate (14)CO(2) for about 1 hour at monthly intervals between April and October, and the subsequent distribution of (14)C in these plants was determined 8 hours, 1 month, 2 months or 4 months after photo-assimilation. In this way, the fate of (14)CO(2) photo-assimilated during different months of the growing season was observed.In the spring, old needles played a significant role in photo-assimilating (14)CO(2) and exporting current photosynthate to the developing new shoots and roots. By July, the new shoot had replaced the old shoot both as the primary photo-assimilating part of the plant and as an exporter, particularly to the root.The root received current photosynthate from the shoot throughout the entire growing season, although plant analysis only 8 hours after photo-assimilation did not always reveal this. Translocation of recent photosynthate from shoot to root was particularly high in August, September, and October.The amounts of photo-assimilated (14)C lost from the plants over a 4 month interval, principally through respiration and photorespiration, were about one-half of that absorbed during photo-assimilation, with the greatest loss occurring within the first month.

PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for HighWire Icon for PubMed Central
    Loading ...
    Support Center