Catalogo Articoli (Spogli Riviste)

OPAC HELP

Titolo:
Control of carbon partitioning and photosynthesis by the triose phosphate/phosphate translocator in transgenic tobacco plants (Nicotiana tabacum L.).I. Comparative physiological analysis of tobacco plants with antisense repression and overexpression of the triose phosphate/phosphate translocator
Autore:
Hausler, RE; Schlieben, NH; Nicolay, P; Fischer, K; Fischer, KL; Flugge, UI;
Indirizzi:
Univ Cologne, Inst Bot, D-50931 Cologne, Germany Univ Cologne Cologne Germany D-50931 Inst Bot, D-50931 Cologne, Germany
Titolo Testata:
PLANTA
fascicolo: 3, volume: 210, anno: 2000,
pagine: 371 - 382
SICI:
0032-0935(200002)210:3<371:COCPAP>2.0.ZU;2-A
Fonte:
ISI
Lingua:
ENG
Soggetto:
SUCROSE-PHOSPHATE SYNTHASE; CHLOROPHYLL FLUORESCENCE; SPINACH-CHLOROPLASTS; POTATO PLANTS; TRANSPORT; STARCH; LEAVES; PYROPHOSPHORYLASE; C-3-PLANTS; METABOLISM;
Keywords:
antisense repression/overexpression; car-bohydrate metabolism; carbon partitioning; Flaveria; Nicotiana (transgenic); triose phosphate/phosphate translocator; starch mobilisation;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Agriculture,Biology & Environmental Sciences
Life Sciences
Citazioni:
36
Recensione:
Indirizzi per estratti:
Indirizzo: Hausler, RE Univ Cologne, Inst Bot, Gyrhofstr 15, D-50931 Cologne, GermanyUniv Cologne Gyrhofstr 15 Cologne Germany D-50931 ne, Germany
Citazione:
R.E. Hausler et al., "Control of carbon partitioning and photosynthesis by the triose phosphate/phosphate translocator in transgenic tobacco plants (Nicotiana tabacum L.).I. Comparative physiological analysis of tobacco plants with antisense repression and overexpression of the triose phosphate/phosphate translocator", PLANTA, 210(3), 2000, pp. 371-382

Abstract

The physiological properties of transgenic tobacco plants (Nicotiana tabacum L.) with decreased or increased transport capacities of the chloroplast triose phosphate/phosphate translocator (TPT) were compared in order to investigate the extent to which the TPT controls metabolic fluxes in wild-typetobacco. For this purpose, tobacco lines with an antisense repression of the endogenous TPT (alpha TPT) and tobacco lines overexpressing the TPT geneisolated from the C-4 plant Flaveria trinervia (FtTPT) were used. The F. trinervia TPT expressed in yeast cells exhibited transport characteristics identical to the TPT from C-3 plants. Neither antisense TPT plants nor FtTPToverexpressors showed a phenotype when grown in a greenhouse in air. Contents of starch and soluble sugars in upper source leaves were similar in TPTunderexpressors and FtTPT overexpressors compared to the wild type at the end of the photoperiod. The FtTPT overexpressors incorporated more (CO2)-C-14 in sucrose than the wild type, indicating that the TPT limits sucrose biosynthesis in the wild type. There were only small effects on labelling of amino acids and organic acids. The mobilisation of starch was enhanced in alpha TPT lines but decreased in FtTPT overexpressors compared to the wild type. Enzymes involved in starch mobilisation or utilisation, such as alpha-amylase or hexokinase were increased in alpha TPT plants and, in the case of amylases, decreased in FtTPT overexpressors. Moreover, alpha-amylase activity exhibited a pronounced diurnal Variation in alpha TPT lines with a maximum activity after 8 h in the light. These changes in starch hydrolytic activities were confirmed by activity staining of native gels. Activities of glucan phosphorylases were unaffected by either a decrease or an increase in TPT activity. There were also effects of TPT activities on steady-state levels of phosphorylated intermediates as well as total amino acids and malate. In air, there was no or little effect of altered TPT transport activityon either rates of photosynthetic electron transport and/or CO2 assimilation. However, in elevated CO2 (1500 mu l.1(-1)) and low O-2 (2%) the rate ofCO2 assimilation was decreased in the alpha TPT lines and was slightly higher in FtTPT lines. This shows that the TPT limits maximum rates of photosynthesis in the wild type.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 03/04/20 alle ore 10:54:18