23 research outputs found
Suppression of Chlorella vulgaris Growth by Cadmium, Lead, and Copper Stress and Its Restoration by Endogenous Brassinolide
Brassinosteroids play a significant role in the amelioration of various abiotic and biotic stresses. In order to elaborate their roles in plants subjected to heavy metals stress, Chlorella vulgaris cultures treated with 10−8 M brassinolide (BL) were exposed to 10−6–10−4 M heavy metals (cadmium, lead and copper) application. Under heavy metals stress, the growth and chemical composition (chlorophyll, monosaccharides, and protein content) have been decreased during the first 48 h of cultivation. The inhibitory effect of heavy metals on C. vulgaris cultures was arranged in the following order: copper > lead > cadmium. C. vulgaris cultures treated with BL in the absence or presence of heavy metals showed no differences in the endogenous level of BL. On the other hand, treatment with heavy metals results in BL level very similar to that of control cell cultures. These results suggest that the activation of brassinosteroids biosynthesis, via an increase of endogenous BL, is not essential for the growth and development of C. vulgaris cells in response to heavy metals stress. Simultaneously, BL enhanced the content of indole-3-acetic acid, zeatin, and abscisic acid in cultures treated with heavy metals. Levels per cell of chlorophylls, protein, and monosaccharides are all increased by BL treatment when compared to nontreated control cells. Application of BL to C. vulgaris cultures reduced the accumulation of heavy metals stress on growth, prevented chlorophyll, monosaccharides, and protein loss, and increased phytochelatins content. The arrested growth of C. vulgaris cells treated with heavy metals was restored by the coapplication of BL. It suggested that BL overcame the inhibitory effect of heavy metals. From these results, it can be concluded that BL plays the positive role in the alleviation of heavy metals stress
Determinants of civil society influence:the case of international development and humanitarian NGOs in the Czech Republic and Hungary
Accession to the EU has had ambiguous effects on civil society organizations (CSOs) in the East Central European countries. A general observation is that accession has not led to the systematic empowerment of CSOs in terms of growing influence on national policy making. This article investigates the determinants of successful CSO advocacy by looking at international development and humanitarian NGOs (NGDOs) in the Czech Republic and Hungary. Reforms in the past decade in the Czech Republic have created an international development policy largely in line with NGDO interests, while Hungary’s ministry of foreign affairs seems to have been unresponsive to reform demands from civil society. The article argues that there is clear evidence of NGDO influence in the Czech Republic on international development policy, which is because of the fact that Czech NGDOs have been able solve problems of collective actions, while the Hungarian NGDO sector remains fragmented. They also have relatively stronger capacities, can rely on greater public support and can thus present more legitimate demands towards their government