Alejandra Yáñez - Academia.edu (original) (raw)

Papers by Alejandra Yáñez

Measurements were performed from anthesis to maturity on the tolerant (‘LE 2384’; A and ... more Measurements were performed from anthesis to maturity on the tolerant (‘LE 2384’; A and C) and susceptible (‘Fontagro 69’; B and D) genotypes, grown under water stress (WS) and full irrigation (FI) conditions, in experiment 1 (A and B) and experiment 2 (C and D). Values are the mean ± SE of four replicates, * P <0.05 (according to Duncan’s test).</p

Genotypes evaluated in experiments 1 and 2, and their level of tolerance to water stress... more Genotypes evaluated in experiments 1 and 2, and their level of tolerance to water stress under field conditions, according to the yield tolerance index (YTI).</p

Data are from evaluations performed at 0, 7, 14 and 21 days after anthesis, for the geno... more Data are from evaluations performed at 0, 7, 14 and 21 days after anthesis, for the genotype “LE 2384” grown under water stress (unshaded matrix) and full irrigation conditions (shaded matrix).</p

Significance levels from ANOVA performed for the glucose, fructose, sucrose, fructan and... more Significance levels from ANOVA performed for the glucose, fructose, sucrose, fructan and water-soluble carbohydrate (WSC) concentration in wheat stems measured in experiment 2.</p

Data are from different days after anthesis (0, 7, 14, and 21), in ‘LE2384’ and ‘Fontagr... more Data are from different days after anthesis (0, 7, 14, and 21), in ‘LE2384’ and ‘Fontagro 69’ genotypes, grown under water stress (WS) and full irrigation (FI) conditions. In A) each point is a sampling date (two sampling dates are superimposed in ´Fontagro 69´). In B) 1-FFTA is fructan 1-fructosyltransferase A; 1-FFTB is fructan 1-fructosyltransferase B; 1-SST is sucrose 1-fructosyltransferase; 6-SFT is sucrose 6-fructosyltransferase; 1-FEHw1 is fructan 1-exohydrolase w1; 1-FEHw2 is fructan 2-exohydrolase w2; 1-FEHw3 is fructan 3-exohydrolase w3; and 6-FEH is fructan 6-exohydrolase.</p

A) grain yield per plant (GY), B) thousand kernel weight (TKW), C) number of kernels per... more A) grain yield per plant (GY), B) thousand kernel weight (TKW), C) number of kernels per spike (NKS), and D) number of spikelets per spike (NSS). Values are the mean ± SE of four replicates. The lowercase letters above the bars represent significant differences at P<0.05 according to Duncan’s test.</p

The expression of four fructosyltransferase (1-FFTA, 1-FFTB, 1-SST and 6-SFT) and four f... more The expression of four fructosyltransferase (1-FFTA, 1-FFTB, 1-SST and 6-SFT) and four fructan exohydrolase (1-FEHw1, 1-FEHw2, 1-FEHw3 and 6-FEH) genes was determined in the stems from d0 (anthesis) to 21 days after anthesis (d21), in ‘LE 2384’ and ‘Fontagro 69’ genotypes, grown under water stress (WS) and full irrigation (FI) conditions. Levels of expression were measured by qRT-PCR using primers displayed in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0177667#pone.0177667.t002" target="_blank">Table 2</a>, and the relative expression calculated by 2–ΔΔCt method described in Material and Methods. Vertical lines represent the mean ± SE of three biological replicates, significant differences at P< 0.05*, P<0.001, ** and P<0.0001***.</p

Plants, 2021

Water deficit represents an important challenge for wheat production in many regions of the world... more Water deficit represents an important challenge for wheat production in many regions of the world. Accumulation and remobilization of water-soluble carbohydrates (WSCs) in stems are part of the physiological responses regulated by plants to cope with water stress and, in turn, determine grain yield (GY). The genetic mechanisms underlying the variation in WSC are only partially understood. In this study, we aimed to identify Single Nucleotide Polymorphism (SNP) markers that account for variation in a suite of WSC and GY, evaluated in 225 cultivars and advanced lines of spring wheat. These genotypes were established in two sites in the Mediterranean region of Central Chile, under water-limited and full irrigation conditions, and assessed in two growing seasons, namely anthesis and maturity growth periods. A genome-wide association study (GWAS) was performed by using 3243 SNP markers. Genetic variance accounted for 5 to 52% of phenotypic variation of the assessed traits. A rapid linkag...

Frontiers in Psychology, 2021

Early adolescence is a developmental stage that comprises some basic interactional processes with... more Early adolescence is a developmental stage that comprises some basic interactional processes with parents, which can be described as gaining autonomy while maintaining relatedness. Studying how maternal and paternal involvement influence the life satisfaction of sons and daughters during early adolescence is especially important while seeking to understand the challenges of this developmental stage. In this paper, we investigate the differential effects of maternal and paternal involvement, as assessed by sons and daughters, on their life satisfaction during early adolescence. We use a unique survey conducted in Chile, The National Survey on Student Trajectories and Transitions, focusing on a subsample of 497 early adolescents attending 5th to 8th grade (60% female, M age = 12.42, SD = 1.18). Our findings indicate that both paternal and maternal involvement are positively correlated with the life satisfaction of adolescents. We also find that the gender of adolescents moderates the ...

Photosynthesis is a fundamental process for life, converting solar energy into chemical energy. T... more Photosynthesis is a fundamental process for life, converting solar energy into chemical energy. This then powers the assimilation of carbon into organic compounds, like carbohydrates, which are used to synthesize other compounds such as organic acids, amino acids and lipids to form the basic components for biomass accumulation. Water-soluble carbohydrates (WSCs) play a central role in the metabolism of plants as carbon and energy sources in cells, and their levels are continuously adjusted as a result of the balance between supply and demand of carbon at the whole plant level. As a consequence, the metabolism of sugars is very dynamic and varies with the stage of development of plants and in response to the environment. Fructans are the largest reserve of carbohydrates in approximately 15% of higher plants. They are synthesized from sucrose in the vacuole by a group of fructosyltransferase (FT) enzymes and catalysed by fructan exohydrolase (FEH) enzymes. They can be found in vegetat...

PLOS ONE

The genetic and physiological mechanisms underlying the relationship between water-soluble carboh... more The genetic and physiological mechanisms underlying the relationship between water-soluble carbohydrates (WSC) and water stress tolerance are scarcely known. This study aimed to evaluate the main WSC in stems, and the expression of genes involved in fructan metabolism in wheat genotypes growing in a glasshouse with water stress (WS; 50% field capacity from heading) and full irrigation (FI; 100% field capacity). Eight wheat genotypes (five tolerant and three susceptible to water stress) were evaluated initially (experiment 1) and the two most contrasting genotypes in terms of WSC accumulation were evaluated in a subsequent experiment (experiment 2). Maximum accumulation of WSC occurred 10-20 days after anthesis. Under WS, the stress-tolerant genotype exhibited higher concentrations of WSC, glucose, fructose and fructan in the stems, compared to FI. In addition, the stress-tolerant genotype exhibited higher up-regulation of the fructan 1-fructosyltransferase B (1-FFTB) and fructan 1-exohydrolase w2 (1-FEHw2) genes, whereas the susceptible cultivar presented an up-regulation of the fructan 6-fructosyltransferase (6-SFT) and fructan 1-exohydrolase w3 (1-FEHw3) genes. Our results indicated clear differences in the pattern of WSC accumulation and the expression of genes regulating fructan metabolism between the tolerant and susceptible genotypes under WS.

Frontiers in Plant Science, 2016

Different physiological traits have been proposed as key traits associated with yield potential a... more Different physiological traits have been proposed as key traits associated with yield potential as well as performance under water stress. The aim of this paper is to examine the genotypic variability of leaf chlorophyll, stem water-soluble carbohydrate content and carbon isotope discrimination (13 C), and their relationship with grain yield (GY) and other agronomical traits, under contrasting water conditions in a Mediterranean environment. The study was performed on a large collection of 384 wheat genotypes grown under water stress (WS, rainfed), mild water stress (MWS, deficit irrigation), and full irrigation (FI). The average GY of two growing seasons was 2.4, 4.8, and 8.9 Mg ha −1 under WS, MWS, and FI, respectively. Chlorophyll content at anthesis was positively correlated with GY (except under FI in 2011) and the agronomical components kernels per spike (KS) and thousand kernel weight (TKW). The WSC content at anthesis (WSCCa) was negatively correlated with spikes per square meter (SM2), but positively correlated with KS and TKW under WS and FI conditions. As a consequence, the relationships between WSCCa with GY were low or not significant. Therefore, selecting for high stem WSC would not necessary lead to genotypes of GY potential. The relationship between 13 C and GY was positive under FI and MWS but negative under severe WS (in 2011), indicating higher water use under yield potential and MWS conditions.

Plants, 2021

Frontiers in Psychology, 2021

PLOS ONE

Frontiers in Plant Science, 2016