Adaptive Response

Borana pastoralists in southern Ethiopia are faced with the challenge of developing more efficient and sustainable use of natural resources. In past decades poorly adapted development interventions and inadequate land-use policies aggravated by population growth have weakened pastoral rangeland management. Ignoring pastoralists’ technical and organizational capacities has contributed to progressive land degradation, the erosion of social structures and poverty. The Endogenous Livestock Development concept recognises pastoralists’ indigenous knowledge-based strategies and priorities, and uses them as the bases for further development of their production system and social relations, to be utilized, improved and combined with modern technologies. This paper explores the Borana pastoralists’ adaptive strategies for improved utilization of natural resources and the manner in which they respond to environmental risk and external influences such as water development and new formal administ...

With an objective to determine the period of persistence of the metal-induced adaptive response to chemical mutagens and heavy metals, growing root meristems of Allium cepa were conditioned by cadmium sulfate (CdSO4), 4×10−7 and 4×10−6 M for 1 h and subsequently challenged by maleic hydrazide (MH), 5×10−3 M or methyl mercuric chloride (MMCl), 1.26×10−6 M for 3 h at different time intervals ranging from a few minutes to several hours following the conditioning dose. Root meristems, fixed at regular intervals during recovery from 6 to 48 h, were cytologically analysed for cells with micronuclei (MNC). The adaptive responses to MH and MMCl were observed as early as 5 min after the Cd-conditioning that persisted for at least 48 h. Metabolic inhibitors, cycloheximide (CH), 10−7 M and buthionine sulfoximine (BSO), 10−4 M administered either prior to or simultaneous with Cd-conditioning effectively prevented the adaptive response to MH. Whereas BSO, an inhibitor of phytochelatin synthesis, prevented the adaptive responses from 15 min to 8 h after the conditioning dose, CH an inhibitor of cytoplasmic protein synthesis prevented the same from 6 to 48 h. The findings underscored the differential roles of phytochelatins and proteins underlying the foregone metallo-adaptive response.

Micropropagation of Origanum vulgare L. by shoot buds, as a potential model system for studying carbon skeleton diversion from growth to secondary metabolism as adaptive response to nutrient deficiency, has been performed. In addition, the antioxidant phenolic compounds, produced by shoots under nutritional stress or in response to exogenously added proline, have been studied. Caffeic acid, rosmarinic acid, and lithospermic acid B have been isolated in oregano shoot cultures by reversed-phase high-performance liquid chromatography, and their structures have been elucidated by tandem mass spectrometry. Both nutritional stress, which in turn causes a moderate increase of constitutive free proline, and exogenous proline affect growth and antioxidant phenolic content of oregano shoots, compared to control.The role of proline, and the associated redox cycle, as a form of metabolic signaling based on a transfer of redox potential amongst interacting cell pathways, which in turn elicit phenolic metabolism via stimulated carbon flux through oxidative pentose phosphate pathway, is discussed. Furthermore, the potential use of oregano tissue and callus cultures as a new strategy to enable the production of useful secondary metabolites on a commercial scale is also discussed.

Oxidative stress is involved in the pathophysiology of diabetes mellitus. In the present study, 68 patients with type 2 diabetes mellitus and 31 clinically healthy individuals were evaluated. The patients were divided into two groups. Group 1 included 29 patients without diabetic complications and group 2 consisted of 39 patients with diabetic complications. Erythrocyte glutathione, superoxide dismutase, and thiobarbituric acid-reactive substance levels as well as plasma antioxidant vitamins C and E, and serum total glutathione-S-transferase, ceruloplasmin, and protein thiols were estimated by using spectro-photometer. A significant decrease of erythrocyte glutathione was observed in group 1 when compared with the controls. Thiols decreased in group 2. An increase in glutathione-S-transferase, ceruloplasmin, superoxide dismutase, and vitamins C and E levels was noted in patients with diabetes mellitus. Thiobarbituric acid-reactive substance levels decreased in group 1 but increased ...

L’etude a pour objet la reponse adaptative du niebe (Vigna unguiculata (L.) Walp.) a un stress hydrique s’exercant en debut de formation des gousses. La regulation de la teneur en glucides, notamment celle du saccharose et de l’amidon, a ete suivie chez deux varietes : Gorom local et KN1. La masse specifique foliaire et les composantes de rendement ont ete egalement determinees. Une diminution de la quantite d’amidon et le maintien d’une teneur assez elevee de saccharose au cours de la journee ont ete observes chez la variete Gorom stressee. Chez la variete KN1, en revanche, le deficit hydrique a reduit considerablement la teneur en ces glucides. En conditions de stress, la masse specifique foliaire ainsi que les caracteristiques agromorphologiques telles que le nombre de gousses par pot, la masse de matiere seche de 100 graines sont plus elevees chez la variete Gorom que chez KN1. De par la variation de la teneur en saccharose et en amidon, la masse specifique foliaire et les carac...

Formal planning for climate change adaptation is emerging rapidly at a range of geo-political scales. This first generation of adaptation plans provides useful information regarding how institutions are framing the issue of adaptation and the range of processes that are recognized as being part of an adaptation response. To better understand adaptation planning among developed nations, a set of 57 adaptation plans from Australia, the United Kingdom and the United States was evaluated against a suite of 19 planning processes identified from existing guidance instruments for adaptation planning. Total scores among evaluated plans ranged from 16% of the maximum possible score to 61%, with an average of 37%. These results suggest adaptation plans are largely under-developed. Critical weaknesses in adaptation planning are related to limited consideration for non-climatic factors as well as neglect for issues of adaptive capacity including entitlements to various forms of capital needed for effective adaptation. Such gaps in planning suggest there are opportunities for institutions to make better use of existing guidance for adaptation planning and the need to consider the broader governance context in which adaptation will occur. In addition, the adaptation options prescribed by adaptation plans reflect a preferential bias toward low-risk capacity-building (72% of identified options) over the delivery of specific actions to reduce vulnerability. To the extent these findings are representative of the state of developed nation adaptation planning, there appear to be significant deficiencies in climate change preparedness, even among those nations often assumed to have the greatest adaptive capacity.

Bacteria rely on two-component signaling systems in their adaptive responses to environmental changes. Typically, the two-component system consists of a sensory histidine kinase that signals by transferring a phosphoryl group to a secondary response regulator that ultimately relays the signal to the cell. Some of these sensors use PAS (Per-Arnt-Sin) domains. A new member of the PAS super family is the LOV (light, oxygen, voltage) domain, a 10-kDa flavoprotein that functions as a light-sensory module in plant, algal, fungal, and bacterial blue-light receptors. Putative LOV domains have been identified in the genomes of many higher and lower eukaryotes, plants, eubacteria, archaebacteria, and particularly in genes coding for histidine kinases (LOV-histidine kinases, LOV-HKs) of plant and animal pathogenic bacteria, including Brucella. We describe here biochemical, photochemical, and biophysical methodology to purify these enzymes and to characterize their light-activation process.

In the present work, we investigated the potential use of several antioxidant enzymes in wild mussels (Mytilus galloprovincialis) as biomarkers of marine pollution. The enzymatic activity levels of glutathione S-transferase (GST), glutathione peroxidase (GPx) and catalase (CAT) were measured in gills and digestive gland. Those enzymes participate in the cellular defense system that is involved in the adaptive response of organisms to chemical pollution. Adult mussels were collected at five sampling sites located at the Ría de Pontevedra and Ría de Vigo. Seasonal variations in the control site were observed for the CAT activity, but no significant variability was found for GST and GPx. Mussels from the most polluted sites exhibited a significantly greater GST activity compared to the control site (p<0.05) during the sampling period, whereas GPx and CAT activities have not such a marked pattern. Trace metals, PAHs, PCBs and DDT contents in mussels at sampling sites showed highly si...

The life span alteration after γ-irradiation and/or paraquat treatment in Drosophila in wild type strain Canton-S and strains with mutations of heat shock factor (1–4 alleles) and heat shock proteins (Hsp70Ba 304 , Hsp83 e6A , Hsp22 EY09909 , Hsp67Bb EY099099 ) was investigated. Chronic low-dose rate γ-irradiation (0.017 and 0.17 cGy/h) on pre-imago stages was used as a priming dose (absorbed doses were 4 and 40 cGy). Paraquat, a free radical inducing agent, was a challenging factor (20 mM for 1 day). It was shown that chronic irradiation led to adaptive response in both sexes except homozygous males and females with mutations of Hsf 4 and Hsp70Ba 304 . The gender-specific differences in stress response were discovered in wild type strain Canton-S, Hsp22 EY09909 Hsp67Bb EY09909 homozygotes and Hsp83 e6A heterozygotes: the adaptive response persisted in males, but not in females. Thus, Drosophila Hsp and Hsf mutation homozygotes did not demonstrate the adaptive response in the majority of cases, implying an important role of those genes in radiation hormesis and adaptation to stresses.