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Micropropagation of Physalis ixocarpa L.

100%

Bergier K. , Wielanek M. , Gajewska E. , Sklodowska M.

Zeszyty Problemowe Postępów Nauk Rolniczych

2007

tom 523

Nickel-induced depression of nitogen assimilation in wheat roots

100%

Gajewska E. , Wielanek M. , Bergier K. , Sklodowska M.

nr 6

The influence of 50 and 100 µM Ni on the activities of nitrate reductase (NR), nitrite reductase (NiR), glutamine synthetase (GS), glutamate synthase (GOGAT), glutamate dehydrogenase (GDH), alanine aminotransferase (AlaAT) and aspartate aminotransferase (AspAT) was studied in the wheat roots. Root fresh weight, tissue Ni, nitrate, ammonium, glutamate and protein concentrations were also determined. Exposure to Ni resulted in a marked reduction in fresh weight of the roots accompanied by a rapid accumulation of Ni in these organs. Both nitrate and ammonium contents in the root tissue were considerably enhanced by Ni stress. While protein content was not significantly influenced by Ni application, glutamate concentration was slightly reduced on the first day after treatment with the higher Ni dose. Treatment of the wheat seedlings with 100 µM Ni led to a decrease in NR activity; however, it did not alter the activation state of this enzyme. Decline in NiR activity observed after application of 100 µM Ni was more pronounced than that in NR. The activities of GS and NADH-GOGAT also showed substantial decreases in response to Ni stress with the latter being more susceptible to this metal. Starting from the fourth day, both aminating and deaminating GDH activities in the roots of the seedlings supplemented with Ni were lower in comparison to the control. While the activity of AspAT remained unaltered after Ni application that of AlaAT showed a considerable enhancement. The results indicate that exposure of the wheat seedlings to Ni resulted in a general depression of nitrogen assimilation in the roots. Increase in the glutamate-producing activity of AlaAT may suggest its involvement in supplying the wheat roots with this amino acid under Ni stress.

Influence of nickel stress on ammonium assimilating enzymes in wheat seedlings

88%

Gajewska E. , Bergier K. , Wielanek M. , Mazur J. , Sklodowska M.

nr 1 Suppl.

Glucosylation of hydroquinone to arbutin by hairy roots of Physalis ixocarpa

75%

Bergier K. , Polaszczyk B. , Gajewska E. , Wielanek M. , Krolicka A. , Sklodowska M.

Zeszyty Problemowe Postępów Nauk Rolniczych

2008

tom 524

P. ixocarpa hairy root cultures were obtained after the transformation with A. rhizogenes strain ATCC 15834. The ability of P. ixocarpa hairy roots to biotransform HQ to arbutin was examined. The roots were treated 3 times with the same HQ concentration on 3 consecutive days or every 3 days. Despite these differences the highest arbutin yield and the highest biotransformation ratio were similar in both variants, 13.1 and 14.4 mg·25 cm⁻³ of the cultures and 67.6% and 70.6%, respectively. However, in the case of shorter intervals between treatments the highest levels of these parameters were achieved earlier. Multiple treatment of lower HQ concentration reduced its harmful effects on root biomass growth.

W wyniku transformacji za pomocą A. rhizogenes otrzymano korzenie włoś- nikowate P. ixocarpa, które wykazywały zdolność biotransformacji hydrochinonu do arbutyny. Korzenie 3-krotnie traktowano tym samym stężeniem HQ, ale w różnych odstępach czasu, co 24 godz. i co 72 godz. Pomimo tych różnic największa wydajność arbutyny jak również najwyższy współczynnik biotransformacji dla obu wariantów były podobne i wyniosły odpowiednio, 13.1 i 14,4 mg·25 cm⁻³ hodowli oraz 67,6 i 70,6%. Jednak zastosowanie krótszych czasów pomiędzy poszczególnymi traktowaniami HQ pozwoliło na szybsze uzyskanie maksymalnych wartości dla badanych parametrów. Jednocześnie kilkukrotne traktowanie kultur korzeni włośnikowatych niższymi stężeniami HQ zmniejszyło niekorzystny efekt jego działania na przyrost biomasy korzeni.

Arbutin formation by hairy roots of Physalis ixocarpa treated with hydroquinone

75%

Bergier K. , Polaszczyk B. , Wielanek M. , Gajewska E. , Krolicka A. , Sklodowska M.

nr 1 Suppl.