Examinando por Materia "Stress"

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Comparing the differential expression of selected genes in native Peruvian potatoes in response to early and late drought conditions
(Palm Beach State College, 2017-04-01) Cornelio, Laynet; Perez, Indira; Vazquez, Carlos; Martinez, Diana; Ponce, Olga Patricia; Murata, Emi; Torres, Yerisf; Zuñiga López, Luz Noemí; Orjeda, Gisella; Maul, Dora Pilar; Merino, Carlos
Plant response to drought stress comprises growth inhibition, stomatal closure, an increase in abscisic acid (ABA) biosynthesis and increased antioxidant metabolism, among others. Drought tolerance in plants is linked to photosynthesis and carbohydrate metabolism. Drought-inducible functional proteins include those that protect cells from water deficit and oxidation as well as transcription factors and signaling molecules associated with the water-stress response. Native potatoes from the Andean regions of Peru, Ecuador and Bolivia grow at altitudes as high as 11483 ft. (3500m) above sea level. Because of their high genetic diversity, they are well adapted to the harsh environmental conditions that prevail in the high Andes, including drought. This makes them ideal candidates for gene expression studies associated with drought tolerance. St. Thomas University is collaborating with the Universidad Peruana Cayetano Heredia (UPCH, Lima, Peru), and the Instituto Nacional de Innovacion Agraria (INIA, Huancayo, Peru) in a gene expression study in native potatoes associated with early and late drought responses. Selected drought associated candidate genes from RNA-seq analysis were used in primer design and quantitative RT-PCR analysis. Differential gene expression in tolerant vs. susceptible cultivars has been confirmed for two heat shock proteins, a dehydration-response element binding protein and for a major pollen allergen.
Measuring faecal glucocorticoid metabolites as a non-invasive tool for monitoring adrenocortical activity in South American camelids
(Ingenta, 2013-02-01) Arias, N.; Requena Musucancha, Magno Lucio; Palme, R.
The welfare and productivity of South American camelids may be affected by stressful events. The purpose of this study was to validate a non-invasive method for stress monitoring using faecal samples and to apply it to evaluate a stressful event, such as confinement. For physiological validation, nine alpacas (Vicugna pacos) and six llamas (Lama glama) were subjected to pharmacological stimulation of their adrenal cortex. Serial faecal samples were collected during 48 h before and after stimulation. During confinement, faecal samples from six llamas were collected twice per day during six consecutive days. Faeces belonging to 18 vicuñas (Vicugna vicugna) were collected before and one day after their capture for confinement (Chacu). Faecal cortisol metabolites (FCM) were extracted from each sample and quantified by an 11- oxoaetiocholanolone enzyme immunoassay. Thirty-three and 28 h (median) after ACTH stimulation, FCM concentrations peaked with a ten- and eight-fold increase (median) above baseline in alpacas and llamas, respectively. There were no significant differences in FCM concentrations between sexes. In llamas, FCM concentrations peaked (4.7 times higher than baseline) after five days of confinement in females and after three days (2.7 times) in males. In vicuñas, three times higher FCM levels were observed the day after the start of confinement (in comparison to the starting values). Based on our findings, this non-invasive method is well suited to measure adrenocortical activity in alpacas, llamas and vicuñas. Thus, this method could help to improve management, handling and welfare in wild and domesticated South American camelids.