Pea (Pisum sativum L.) seedlings were exposed to low, moderate and high regimes of ultraviolet-B (UV-B) (ld-B - 4.4, md-B - 13.3 and hd-B - 26.5 kJ m2 d1) or ultraviolet-C (UV-C) (ld-C - 0.1, md-C - 0.3 and hd-C - 0.6 kJ m2 d1) radiations. Concentrations of total phenols, free proline and low-molecular thiol groups were determined in the last formed (young) and older leaves after irradiation for 7, 10 or 14 consecutive days. Shoot length and weight did not changed markedly after 14 days of ld-B and ld-C, but reduced substantially after moderate and high regimes of UV-radiations. Proline decreased upon high doses of irradiation, while in ld-B treated plants, by contrast, an increase was observed. The reduction in total phenols and thiols was stronger after hd-B than after hd-C irradiations, although an induction was found in ld-B treated plants. In contrast to ld-B, ld-C regime led mainly to reductions or insignificant changes in proline, phenols and thiols. Therefore the stress-protection mechanisms are different for low UV-B and UV-C radiations in regard to proline, phenols and thiols.
Phenols, proline and low-molecular thiol levels in pea (Pisum sativum) plants respond differently toward prolonged exposure to ultraviolet-B and ultraviolet-C radiations.
Mapelli S;
2009
Abstract
Pea (Pisum sativum L.) seedlings were exposed to low, moderate and high regimes of ultraviolet-B (UV-B) (ld-B - 4.4, md-B - 13.3 and hd-B - 26.5 kJ m2 d1) or ultraviolet-C (UV-C) (ld-C - 0.1, md-C - 0.3 and hd-C - 0.6 kJ m2 d1) radiations. Concentrations of total phenols, free proline and low-molecular thiol groups were determined in the last formed (young) and older leaves after irradiation for 7, 10 or 14 consecutive days. Shoot length and weight did not changed markedly after 14 days of ld-B and ld-C, but reduced substantially after moderate and high regimes of UV-radiations. Proline decreased upon high doses of irradiation, while in ld-B treated plants, by contrast, an increase was observed. The reduction in total phenols and thiols was stronger after hd-B than after hd-C irradiations, although an induction was found in ld-B treated plants. In contrast to ld-B, ld-C regime led mainly to reductions or insignificant changes in proline, phenols and thiols. Therefore the stress-protection mechanisms are different for low UV-B and UV-C radiations in regard to proline, phenols and thiols.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
