Plants grown in environments with modified
isotopic composition will incorporate the tracer into C-containing
compounds (Avice etal., 1996; Nogues etal., 2004; Aranjuelo et al.,
2008), providing essential information about the C sinks to which
the recently fixed C is delivered. The C labeling method provides,
in a non-invasive and reversible way, information about the role of
source-sink strength of the different plant tissues.