Yucca

Geochronological control is an essential component of paleoseismic evaluation of faults in the Yucca Mountain region. New U-series disequilibrium and thermoluminescence age estimates for pedogenic deposits that bracket surface-rupture events are presented from four sites exposing the Paintbrush Canyon, Bow Ridge and Stagecoach Road faults. Ages show an internal consistency with stratigraphic relationships as well as an overall concordancy between

Significance High temperature (HT) strongly modulates plant growth and eventually threatens yield stability. HT induces biosynthesis of the phytohormone auxin, which in turn increases cellular auxin levels and growth rates in shoots. This mechanism does not control HT-induced root growth and, hence, the role of auxin in this process is currently controversial. Here we show that the putative auxin carrier PIN-LIKES 6 (PILS6) localizes to the endoplasmic reticulum, where it gates nuclear auxin accumulation and perception. HT decreases the abundance of PILS6 proteins, consequently increasing nuclear auxin signaling and root growth. Our data dismantle current controversy, revealing an alternative subcellular mechanism in roots, which links PILS6-dependent control of cellular auxin sensitivity with HT-induced organ growth.

We identified volatiles from the floral headspace of Yucca filamentosa using gas chromatography and mass spectrometry and analyzed floral scent composition and variation among populations pollinated by different yucca moth species. Twenty‐one scent compounds were repeatedly identified and most could be categorized into two major classes: (1) homoterpenes derived from the sesquiterpene alcohol nerolidol and (2) long chain aliphatic hydrocarbons. Two biosynthetic pathways are thus responsible for the majority of floral volatiles in Y. filamentosa. The homoterpene E‐4,8‐dimethylnona‐1,3,7‐triene, which is released systemically by higher plants upon herbivory, was the most abundant compound. Two di‐oxygenated compounds not previously reported as floral compounds also were detected. No differentiation in floral scent was observed between populations pollinated by different yucca moths, nor was there any correlation between chemical distance and geographic distance among populations. The ...

Extreme climate events are transforming plant communities in the desert Southwest of the United States. Abundant precipitation in 1998 associated with El Niño Southern Oscillation (ENSO) stimulated exceptional alien annual plant production in the Mojave Desert that fueled wildfires in 1999. Exacerbated by protracted drought, 80% of the burned Yucca brevifolia, a long‐lived arborescent monocot, and 26% of unburned plants died at Joshua Tree National Park by 2004. Many burned plants <1 m tall died immediately, and survival of all but the tallest, oldest plants declined to the same low level by 2004. Postfire sprouting prolonged survival, but only at the wetter, high‐elevation sites. During succeeding dry years, herbaceous plants were scarce, and individuals of Thomomys bottae (pocket gopher) gnawed the periderm and hollowed stems of Y. brevifolia causing many of them to topple. Thomomys bottae damage reduced plant survivorship at low‐elevation, unburned sites and diminished surviva...

Yucca L. (the Desert Soaptree, Agavaceae) consists of 45 perennial species distributed primarily in the deserts of Mexico and the United States. Although several taxonomic treatments of yuccas exist; the-phylogeny of the group is poorly known. It is unclear which taxa retain primitive characters and how characters have evolved. In addition, relationships of taxa within the genus are uncertain. We compare our phylogeny based upon reproductive characters with a chloroplast phylogeny (Hanson and Rieseberg, 1991 ; Hanson, 1993) and with data from the ITS region of the nuclear genome (Bogler, this volume). The molecular analyses of the chloroplast genome by Hanson and Rieseberg (1991) led to a phylogeny only partially congruent with the traditional morphology-based phylogeny (McKelvey, 1938, 1947) because the cpDNA analysis indicated that chloroplast capture among distantly related, sympatric/parapatric species has been a factor in the evolution of the group. Our results indicate that Yu...

The objective of this study was to evaluate the effects of a phytogenic product (Integri-Phi®) containing Quillaja saponaria and Yucca schidigera saponins and polyphenols, known to reduce inflammation and stimulate cell mediated immune response, on intestinal integrity, welfare, and performance of broilers under typical production environment in Belgium. Three commercial farms with two identical poultry houses each differing in Quillaja and Yucca product (QYP) supplementation only, one control (CTRL) and one QYP supplemented (Integri-Phi® at 250g/t), were monitored for two consecutive production cycles with a total of 464 000 Ross308 broilers; each poultry house cycle serving as a replicate. Conventional industrial farming and commercial feed supplemented with in-feed anticoccidials were applied and were identical for each QYP/CTRL paired replicates. Performance data: average body weight at processing (BW), average daily weight gain (DWG), feed conversion ratio (FCR) corrected at 2500 g BW, European Poultry Efficiency Factor (EPEF) and liveability; total mean lesion scores (TMLS) for the three major Eimeria spp. and dysbacteriosis lesion score from five random birds per replicate at day 21 and 35; and food pad dermatitis (FPD) score for 100 birds per replicate at day 35, as an indicator of birds' welfare, were collected and subjected to statistical analysis by paired t-test with a multiple linear regression analysis that adjusts for slaughter age and feed program. QYP significantly improved BW with 38g (CTRL 2587g and QYP 2625g p=0.018) and DWG with 1.2g (CTRL 65.63g and QY 66.87g p=0.018). FCR was improved numerically with 3 points (CTRL 1.54 and QY 1.51 p=0.142) and EPEF with 16 points (CTRL 408 and QY 424 p=0.116). Liveability did not differ significantly (CTRL 96.725% and QYP 97.462 p=0.495). Coccidiosis control was effective and TMLS were not significantly different between the two groups (CTRL 0.83 and 0.60 and QYP 0.83 and 0.63 at 21 and 35 days with p=0.553 and 0.884 respectively). While non-specific enteritis (dysbacteriosis) scores were significantly lower at 35 days in the QYP group (CTRL 2.63 and 4.00 and QYP 2.80 and 3.50 at 21 and 35 days with p=0.611 and 0.028 respectively). In line with reduced enteritis score at 35 days QYP provided close to significant reduction of FPD at 35 days (CTRL 58.33 and QYP 40.17 p=0.086). Overall results suggest that QYP can reduce intestinal inflammation and improve birds' performance and welfare under commercial farming conditions.

A probabilistic model to predict the lifetimes of the engineered barrier system proposed for the Yucca Mountain repository is described. The model assumes that the titanium Grade-7 drip shield will fail by hydrogen-induced cracking and the Alloy-22 waste package by a combination of passive and crevice corrosion. The model predicts that crevice corrosion of the waste package can be completely avoided ifthe drip shield deflects seepage drips for between 2000 (realistic behaviour) and 6000 years (conservative behaviour). Sensitivity calculations on the crevice corrosion model suggest that early waste package failure is extremely unlikely providing the drip shield performs its function for a minimum of ~ 300 years.

Extreme climate events are transforming plant communities in the desert Southwest of the United States. Abundant precipitation in 1998 associated with El Niño Southern Oscillation (ENSO) stimulated exceptional alien annual plant production in the Mojave Desert that fueled wildfires in 1999. Exacerbated by protracted drought, 80% of the burned Yucca brevifolia, a long‐lived arborescent monocot, and 26% of unburned plants died at Joshua Tree National Park by 2004. Many burned plants <1 m tall died immediately, and survival of all but the tallest, oldest plants declined to the same low level by 2004. Postfire sprouting prolonged survival, but only at the wetter, high‐elevation sites. During succeeding dry years, herbaceous plants were scarce, and individuals of Thomomys bottae (pocket gopher) gnawed the periderm and hollowed stems of Y. brevifolia causing many of them to topple. Thomomys bottae damage reduced plant survivorship at low‐elevation, unburned sites and diminished surviva...

Las saponinas son metabolitos secundarios producidos naturalmente por las plantas debido al estrés biótico. Las plantas del género Yucca se consideran fuente de saponinas, particularmente de glucósidos esteroidales. Debido a su estructura química, son moléculas con diversas propiedades funcionales y con actividad biológica. Este documento explora de manera crítica los procesos tecnológicos reportados para la obtención de saponinas y extractos con saponinas de diversas especies del género Yucca, así como sus propiedades, bioactividad y aplicaciones actuales. Se considera que los extractos con saponinas de yuca presentan un potencial de uso a nivel industrial en diversas áreas, particularmente en tecnología de alimentos, salud y agropecuaria.

Plant growth-promoting rhizobacteria (PGPR) are members of the plant rhizomicrobiome that enhance plant growth and stress resistance by increasing nutrient availability to the plant, producing phytohormones or other secondary metabolites, stimulating plant defense responses against abiotic stresses and pathogens, or fixing nitrogen. The use of PGPR to increase crop yield with minimal environmental impact is a sustainable and readily applicable replacement for a portion of chemical fertilizer and pesticides required for the growth of high-yielding varieties. Increased plant health and productivity have long been gained by applying PGPR as commercial inoculants to crops, although with uneven results. The establishment of plant-PGPR relationships requires the exchange of chemical signals and nutrients between the partners, and polyamines (PAs) are an important class of compounds that act as physiological effectors and signal molecules in plant-microbe interactions. In this review we fo...

In this study, the aerial parts of Moricandia sinaica were evaluated for their in vivo analgesic, anti-inflammatory and antipyretic activities. The analgesic activities were examined using acetic acid-induced writhing, the hot plate test and the tail flick method. The anti-inflammatory and the antipyretic activities were evaluated using carrageenan-induced paw edema in rats and brewer’s yeast-induced pyrexia in mice, respectively. The aqueous fraction of the methanol extract (MS-3) showed to be the most bioactive among the other investigated fractions. At the dose of 500 mg/kg, the fraction (MS-3) showed a significant percentage inhibition of the carrageenan-induced edema by 52.4% (p < 0.05). In addition, MS-3 exhibited a significant inhibition of acetic acid-induced writhes by 44.4% and 61.5% (p < 0.001) at 250-mg/kg and 500-mg/kg doses, respectively. At 120 min post-treatment, the rat groups treated with MS-3 displayed statistically significant reduction in rectal temperatur...

The current study aims to assess the effects of a Quillaja saponaria and Yucca schidigera combination product (QY) and a four-strain Bacillus-based probiotic (PRM) when applied separately or in combination in feed for broilers subjected to a non-specific enteritis challenge model in comparison to infected and uninfected untreated controls (IUC and UUC respectively). The model successfully mimicked field enteritis causing a significant increase in mortality and intestinal inflammation scores, a deterioration in performance and an increase in intestinal pathogen isolation in the IUC compared to UUC. Both products provided significant and complete alleviation of the challenge regarding mortality, body weight and weight homogeneity when used separately. In addition, PRM provided complete alleviation of the challenge regarding feed conversion, EPEF and carcass yield, while QY treatments were not different from UUC in regard to intestinal inflammation scores. Both products provided significant improvement regarding pathogen isolation from the intestinal tract in comparison to IUC but were not equal to UUC. When used together the two products provided further benefits in regard to breast meat yield and reduction of Escherichia coli in the intestinal content to a level not different to UUC and improved processing weight uniformity to a level significantly better than UUC.