Affiliation:
1. Unite Associee Institut National de la Recherche Agronomique de Physiologie et de Biochimie Vegetales, Institut de Recherche en Biologie Appliquee, Universite de Caen, 14032 Caen Cedex, France (J.C.A., A.O., J.B.)
Abstract
Abstract
The flow of 15N and 13C from storage compounds in organs remaining after defoliation (sources) to regrowing tissue (sinks), and 13C losses through root or shoot respiration were assessed by pulse-chase labeling during regrowth of alfalfa (Medicago sativa L.) following shoot removal. A total of 73% of labeled C and 34% of labeled N were mobilized in source organs within 30 d. Although all of the 15N from source organs was recovered in the regrowing tissue, much of the 13C was lost, mainly as CO2 respired from the root (61%) or shoot (8%), and was found to a lesser extent in sink tissue (5%). After 3, 10, or 30 d of regrowth, 87, 66, and 52% of shoot N, respectively, was derived from source tissue storage compounds; the rest resulted from translocation of fixed N2. Overall results suggest that most shoot C was linked to photosynthetic activity rather than being derived from mobilization of stored C in source organs. Furthermore, isotopic analysis of different chemical fractions of plant tissue suggests that between 14 and 58% of the shoot C derived from source tissues was linked to the mobilization of N compounds, not carbohydrates.
Publisher
Oxford University Press (OUP)
Subject
Plant Science,Genetics,Physiology
Cited by
120 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献