Se alquila 'alejamiento' turístico sobre cementerio indio

La noticia aparecía hace unos meses en losmedios: en el barrio de Poble Sec (Barcelona) estaban construyendo un edificio con seis apartamentos plurifamiliares de madera dirigidos a un mercado de turismo responsable. La promotora de estos apartamentos explicaba que se oponía al "turismo de borrachera" y a la "masificación de los barrios" y que apostaba por otros valores como son la "ecología" y lo "social". Todo un manifiesto[...] La notícia apareixia fa uns mesos en losmedios: al barri de Poble Sec (Barcelona) estaven construint un edifici amb sis apartaments plurifamiliars de fusta dirigits a un mercat de turisme responsable. La promotora d'aquests apartaments explicava que s'oposava al 'turisme de borratxera' i de la 'massificació dels barris' i que apostava per altres valors com són la 'ecologia' i el 'social'. Tot un manifest[...

Analysis of the effects of salt treatment in G1 to G3 (in no, one or both parental lines) on phenotypic differences between reciprocal hybrids (Sha×Col vs. Col×Sha) in G4 salt and control treatments.

<p>Analysis was based on a linear mixed model with manually defined contrasts. <i>P</i>-values were corrected for multiple testing according to Benjamini and Hochberg (1995).</p>a<p>♀S: maternal line salt stressed; ♂S: paternal line salt stressed; ♀C: maternal line control; ♂C: paternal line control.</p>***<p><i>P</i>-value <0.001; **<i>P</i>-value <0.01; *<i>P</i>-value <0.05; <i>P</i>-value <0.1.</p

Transgenerational effects of two stress generations displaying three different modes of adaptation to novel environments.

<p>A: Tracking: in genotype Sha two generations of ancestral heat treatment (orange) led to more rosette leaves after three weeks in comparison to ancestral control treatment (white). B: Transgenerational phenotypic plasticity: in genotype Sha, two generations of ancestral salt treatment (blue) led to increased number of siliques per branch when compared to ancestral control conditions (white) under G3 salt conditions, but not G3 control conditions. C: Diversified bet-hedging: in genotype Cvi ancestral heat treatment (orange) increased the variance of total siliques in comparison to ancestral control treatment (white).</p

Characterization of approach herkogamy in the greenhouse.

<p>(<b>A</b>) Means with standard errors (SEs) of fertilization rates in Col-0, BRA, and SIM – upon autonomous selfing, assisted selfing, and pollination of a male-sterile line (pollen siring). Letters above bars indicate significant differences (Tukey's post-hoc significance tests, α = 0.05) within each fertilizing group. (<b>B</b>) Self-fertilization rates in successive siliques along the main stems of Col-0, BRA, and SIM. The regression function is: y  =  exp(a+b*x)/(1+exp(a+b*x)). Coefficients (a/b) of non-linear models are 0.89/0.33, −2.98/0.15 and −5.97/0.035 for Col-0, BRA and SIM, respectively. (<b>C</b>) Measurements of anther height (AH) and stigma height (SH) in flowers of Col-0 (flowers N = 20), BRA (N = 27), and SIM (N = 16) and their hybrids (F1_BRAxCol-0, N = 16; F1_SIMxCol-0, N = 20; F1_SIMxBRA, N = 13). Significant differences (one-way ANOVA) between AH and SH within each genotype are indicated in the white boxes. Letters above bars indicate statistically significant differences (Tukey's post-hoc significance tests, α = 0.05) in AH or SH across all examined accessions. (<b>D</b>) Calculated SAS (SAS  =  SH – AH; means± SEs) of Col-0, BRA, SIM and their hybrids.</p

The influence of ambient temperature on the expression of herkogamy.

<p>Accession means of SAS (the proxy of herkogamy) in Col-0, BRA, and SIM plants grown under different ambient temperatures and identical light conditions are shown.</p

Phenotypic Effects of Salt and Heat Stress over Three Generations in <i>Arabidopsis thaliana</i>

<div><p>Current and predicted environmental change will force many organisms to adapt to novel conditions, especially sessile organisms such as plants. It is therefore important to better understand how plants react to environmental stress and to what extent genotypes differ in such responses. It has been proposed that adaptation to novel conditions could be facilitated by heritable epigenetic changes induced by environmental stress, independent of genetic variation. Here we assessed phenotypic effects of heat and salt stress within and across three generations using four highly inbred <i>Arabidopsis thaliana</i> genotypes (Col, Cvi, Ler and Sha). Salt stress generally decreased fitness, but genotypes were differently affected, suggesting that susceptibility of <i>A. thaliana</i> to salt stress varies among genotypes. Heat stress at an early rosette stage had less detrimental effects but accelerated flowering in three out of four accessions. Additionally, we found three different modes of transgenerational effects on phenotypes, all harboring the potential of being adaptive: heat stress in previous generations induced faster rosette growth in Sha, both under heat and control conditions, resembling a tracking response, while in Cvi, the phenotypic variance of several traits increased, resembling diversified bet-hedging. Salt stress experienced in earlier generations altered plant architecture of Sha under salt but not control conditions, similar to transgenerational phenotypic plasticity. However, transgenerational phenotypic effects depended on the type of stress as well as on genotype, suggesting that such effects may not be a general response leading to adaptation to novel environmental conditions in <i>A. thaliana</i>.</p> </div

Transgenerational effects of heat on rosette leaves at FFD in genotype Cvi indicate diversified bet-hedging.

<p>A: Entire data-set. No differences in number of rosette leaves at FFD were found between G3 treatments when plants experienced the same ancestral treatment. B: For each G1G2 × G3-treatment combination the five plants with the highest silique number were chosen. In plants with ancestral heat treatment, number of rosette leaves differed significantly between G3 heat (HHH) and G3 control (HHC) treatment. When plants were control treated in G1 and G2, no differences were found between G3 treatments. C: For each G1G2 × G3-treatment combination the five plants with the lowest silique number were chosen. No differences in numbers of rosette leaves were found between G3 plants when plants experienced the same ancestral treatments. </p

Correlation analysis to select a subset of independent phenotypic traits.

<p>The heat map shows pairwise Pearson correlations between phenotypic traits (darker colors denote stronger correlations), with data from the heat stress experiments above the diagonal in red and data from the salt stress experiment below the diagonal in blue. Phenotypic traits written in bold letters were selected for statistical analyses.</p

Transgenerational effects of heat treatment in G1 to G3 analyzed separately both for G4 heat and G4 control treatments in Sha-0 and Col-0 using linear mixed models with past treatment as fixed (shown below) and tray as random factors.

b<p><i>P</i>-values were corrected for multiple testing according to Benjamini and Hochberg (1995), which leads to identical P-values for some non-significant traits. ***<i>P</i>-value <0.001; **<i>P</i>-value <0.01; *<i>P</i>-value <0.05;. : <i>P</i>-value <0.1.</p

Environmental Heat and Salt Stress Induce Transgenerational Phenotypic Changes in <i>Arabidopsis thaliana</i>

<div><p>Plants that can adapt their phenotype may be more likely to survive changing environmental conditions. Heritable epigenetic variation could provide a way to rapidly adapt to such changes. Here we tested whether environmental stress induces heritable, potentially adaptive phenotypic changes independent of genetic variation over few generations in <i>Arabidopsis thaliana</i>. We grew two accessions (Col-0, Sha-0) of <i>A. thaliana</i> for three generations under salt, heat and control conditions and tested for induced heritable phenotypic changes in the fourth generation (G4) and in reciprocal F1 hybrids generated in generation three. Using these crosses we further tested whether phenotypic changes were maternally or paternally transmitted. In generation five (G5), we assessed whether phenotypic effects persisted over two generations in the absence of stress. We found that exposure to heat stress in previous generations accelerated flowering under G4 control conditions in Sha-0, but heritable effects disappeared in G5 after two generations without stress exposure. Previous exposure to salt stress increased salt tolerance in one of two reciprocal F1 hybrids. Transgenerational effects were maternally and paternally inherited. Lacking genetic variability, maternal and paternal inheritance and reversibility of transgenerational effects together indicate that stress can induce heritable, potentially adaptive phenotypic changes, probably through epigenetic mechanisms. These effects were strongly dependent on plant genotype and may not be a general response to stress in <i>A. thaliana</i>.</p> </div