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Titolo:
Acclimation of chloroplast transglutaminase to high NaCl concentration in a polyamine-deficient variant strain of Dunaliella salina and in its wild type
Autore:
Dondini, L; Bonazzi, S; Del Duca, S; Bregoli, AM; Serafini-Fracassini, D;
Indirizzi:
Univ Bologna, Dipartimento Biol Evoluzionist Sperimentale, Sede Bot, I-40126 Bologna, Italy Univ Bologna Bologna Italy I-40126 ale, Sede Bot, I-40126 Bologna, Italy
Titolo Testata:
JOURNAL OF PLANT PHYSIOLOGY
fascicolo: 2, volume: 158, anno: 2001,
pagine: 185 - 197
SICI:
0176-1617(200102)158:2<185:AOCTTH>2.0.ZU;2-5
Fonte:
ISI
Lingua:
ENG
Soggetto:
BARLEY LEAF-DISKS; HELIANTHUS-TUBEROSUS; PHOTOSYSTEM-II; CELL-CYCLE; PHOTOSYNTHETIC APPARATUS; THYLAKOID MEMBRANES; IONIC STRESS; OAT LEAVES; CHLOROPHYLL; PROTEIN;
Keywords:
chloroplast; Dunaliella salina Teodor; light; polyamine; protein modification; salt acclimation; salt stress; transglutaminase;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Agriculture,Biology & Environmental Sciences
Life Sciences
Citazioni:
51
Recensione:
Indirizzi per estratti:
Indirizzo: Serafini-Fracassini, D Univ Bologna, Dipartimento Biol Evoluzionist Sperimentale, Sede Bot, Via Irnerio 42, I-40126 Bologna, Italy Univ Bologna Via Irnerio 42 Bologna Italy I-40126
Citazione:
L. Dondini et al., "Acclimation of chloroplast transglutaminase to high NaCl concentration in a polyamine-deficient variant strain of Dunaliella salina and in its wild type", J PLANT PHY, 158(2), 2001, pp. 185-197

Abstract

The wild type (Wt) and the polyamine-deficient strain (PA(-)vs) of the halotolerant Dunaliella salina were subjected to stress caused by 3.5 mol/L NaCl concentration. The chloroplasts were isolated and the molecular aspects of their reaction to salt stress were studied together with their recovery response to these hyper-saline conditions. In the Wt, the photosynthetic complexes were found to be severely affectedby salt stress under light conditions. Transglutaminases, which are present in chloroplasts as two units of 25 and 50 kDa, were immunorecognized by antibodies raised against rat prostatic gland transglutaminase. The amount, in particular that of the 50 kDa unit, underwent an immediate change following hyper-saline stress. These concentration changes were found to coincidewith variations in enzymic activity, which is also affected by the presence or absence of light. The PA(-)vs has a concentration of proteins and chlorophylls which is muchlower than that of the Wt. In addition, the PA(-)vs appeared to be more severely affected by both salt and subculture stresses. Its recovery time wasalso longer. Its TGase activity increased after salt stress and was alwayshigher in the light than in the dark, except soon after subculture, showing an additive stress effect of salt and light. In the PA(-)vs acclimated tohigh salinity, or immediately after stress application, the chloroplast content of chlorophyll a and b was considerably enhanced, like the TGase activity (by two-fold or more), and these changes exhibited almost coincident behaviours. Some transglutaminase substrates (proteins of 68, 55, 29 and 27 kDa) were found to be similar to those present in higher plants (thylakoid photosynthetic complexes and Rubisco). They were more markedly labelled by [1,4-C-14]polyamines when the transglutaminase assay was performed in the light thanin the dark, and much more in algae already acclimated to hyper-saline conditions than in those cultured in the optimal saline medium, or subjected to stress. The amount of 68 and 55 kDa polypeptides was particularly high inthe 3.5 mol/L NaCl acclimated cells. The possible role of poly amine conjugation in the assembly of chloroplast proteins in cells affected by salt stress is discussed.

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Documento generato il 11/07/20 alle ore 21:02:22