TY  - JOUR
AU  - McQueen, J. C.
AU  - Minchin, P. E. H.
AU  - Thorpe, M. R.
AU  - Silvester, W. B.
TI  - Short-term storage of carbohydrate in stem tissue of apple (Malus domestica), a woody perennial: evidence for involvement of the apoplast
JO  - Functional plant biology
VL  - 32
SN  - 1445-4408
CY  - Collingwood, Victoria
PB  - CSIRO Publ.
M1  - PreJuSER-47497
SP  - 1027 - 1031
PY  - 2005
N1  - Record converted from VDB: 12.11.2012
AB  - This work investigates the pathway and mechanism for lateral retrieval of carbohydrate into the transport phloem of apple stems ( Malus domestica Borkh.). A heat exchanger was set up on the stem, allowing rapid chilling and subsequent re-warming of stem segments while the time course of axial transport of C-11-labelled photoassimilate was measured at a position similar to 65 mm downstream of the heat exchanger. Whenever axial transport was blocked by a sudden chill at the heat exchanger, transport 65 mm downstream from the blockage immediately slowed but did not stop, showing that there was retrieval of solutes into the pathway ( buffering), within that 65 mm of stem, to help maintain the axial flow. Use of PCMBS, an inhibitor of sugar transporters, showed that the buffering included retrieval of sugar from the apoplast. We concluded that in apple, apoplastic sugar in stem tissue can buffer phloem transport during short-term changes in supply and demand for carbohydrates. Buffering was stronger when mobile reserves in the stem were higher, for example late in the photoperiod, or if carbohydrate demand in the terminal sink was increased. We also suggest that the concentration of sugars in the apoplast is a regulator of carbohydrate storage and re-mobilisation.
KW  - J (WoSType)
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000232856600006
DO  - DOI:10.1071/FP05082
UR  - https://juser.fz-juelich.de/record/47497
ER  -