Approaches for the analysis of wheat adaptation and abiotic stress responses in Andalusia

Trabajo presentado en el II Spanish Symposium on Physiology and Breeding of Cereals (II SEFiMeC), celebrado en Córdoba (España) el 6 y 7 de marzo de 2019.-- Organized by excellence network AGL2016-81855-REDT.Wheat is one of the most important cereal crops worldwide as a staple food. It possesses high phenotypic plasticity, due to the presence of a large, polyploid and complex genome with three homoeologous genomes (A, B and D). This success facilitates its adaptation to most agricultural conditions across temperate regions, as Mediterranean environments, where thermo-pluviometrical factors are highly erratic and unpredictable. As a consequence of these changeable conditions, drought can be a major stress which affects the growth, development and grain filling stages of wheat crops at the molecular and physiological levels. Nevertheless, the mechanisms and gene networks involved in wheat field drought stress responses, are still largely unknown. We have integrated different agronomic and genomic approaches to assess stress-responses in several wheat panels and lines, grown under field conditions in different environments of Andalusia. Physiological measures, together with hyperspectral and thermal imagery analyses, were used to determine the nutritional, photosynthetic and water status in the field. These data, when evaluated together with transcriptomic analyses, can be used to assess the molecular basis of wheat drought-responses under field conditions. As result, transcriptional changes were found related to alterations at the physiological level. At the molecular level, a complex structure for drought-responses was found, comprising the presence of gene clusters with differential expression patterns, the influence on biosynthetic pathways such as carotenoids or the implication of gene families such as dehydrins. In addition, the genome-wide association (GWAS) approach was used for the assessment of marker-trait associations (MTA) in agronomic performance and quality traits. Transcriptomic data were used to inform the candidate genes selection process. These results and approaches can be useful for current wheat breeding programs in Andalusia focused on wheat adaption to stress conditions and quality improvement.Funding from Junta de Andalucía project P12-AGR0482 is gratefully acknowledged

The Genomic Architecture of Field Drought Responses in Wheat

Trabajo presentado en la Plant and Animal Genome XXVII Conference (PAG), celebrada San Diego del 12 al 16 de enero de 2019.Wheat can adapt to most agricultural conditions across temperate regions. Although drought is a major cause of yield and quality losses, the adaptivemechanisms and gene networks underlying drought responses in the field remain largely unknown. To address this issue, we utilized an interdisciplinaryapproach involving field water status phenotyping, sampling, and gene expression analyses. Changes at the transcriptional level were reflected in the remotesensing physiological data from the field. We characterized a complex genomic architecture for drought responses under field conditions, involving genehomeolog specialization, multiple gene clusters, gene families, miRNAs, and transcription factors. The results of this study provide a new focus for genomics-assisted breeding of drought-tolerant wheat cultivars

The Gene Networks Involved in Wheat Drought Response

Trabajo presentado en el PAG Asia 2019 (The International conference on the Status of Plant & Animal Genome Research), celebrado en Futian Shangri-La Shenzhen (China) del 6 al 8 de junio de 2019.Wheat can adapt to most agricultural conditions across temperate regions. Although drought is a major cause of yield and quality losses, the adaptive mechanisms and gene networks underlying drought responses in the field remain largely unknown. Interdisciplinary studies involving field water status phenotyping now provide a basis for interpreting gene expression analyses and show that changes at the transcriptional level were reflected in the remote sensing physiological data from the field. The dehydrin family of genes provided a focus for the study and indicated that the genes located on the group 6 chromosomes were particularly important in drought response

Early Obesity: Risk Factor for Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD), defined as fat accumulation greater than 5% in hepatocytes, may progress to fibrosis or cirrhosis later in life. NAFLD prevalence in adolescents has increased significantly in direct relation with obesity prevalence. Fatty liver has become the most frequent indication for liver transplantation in adults. Objective: The aim of the study was to identify anthropometric variables during the first 10 years of life associated to the risk of developing NAFLD in adolescence. Methods: Longitudinal cohort study 'Growth and Obesity Chilean Cohort Study' (GOCS) consisting of 513 children born in 2002 to 2003, with yearly anthropometric data collected over a 10-year period. The presence of intrahepatic fat in the livers of subjects 14 to 16 years of age was determined using abdominal ultrasound. In addition, elastography was performed on all participants with ultrasound evidence of NAFLD. Results: 9.7% of the participants presented findings compatible with NAFLD. After 2 years of age, obesity significantly and progressively increased the probability of NAFLD occurrence in adolescence. Obesity at 5 years of age was associated with the highest OR for NAFLD, reaching values of 8.91 (95% CI 3.03-16.11). Among participants with NAFLD, those with altered liver elasticity (>= 7 kPa) had greater weight, BMIz-score, waist and hip circumference, and altered liver enzymes (P < 0.05). Conclusion: The risk of developing NAFLD in adolescence increases progressively with early obesity starting at age 2 years.Comisión Nacional de Investigación Científica y Tecnológica (CONICYT) CONICYT FONDECYT N81161456 Comisión Nacional de Investigación Científica y Tecnológica (CONICYT) N82218023

Hotspots in the genomic architecture of field drought responses in wheat as breeding targets

Wheat can adapt to most agricultural conditions across temperate regions. This success is the result of phenotypic plasticity conferred by a large and complex genome composed of three homoeologous genomes (A, B, and D). Although drought is a major cause of yield and quality loss in wheat, the adaptive mechanisms and gene networks underlying drought responses in the field remain largely unknown. Here, we addressed this by utilizing an interdisciplinary approach involving field water status phenotyping, sampling, and gene expression analyses. Overall, changes at the transcriptional level were reflected in plant spectral traits amenable to field-level physiological measurements, although changes in photosynthesis-related pathways were found likely to be under more complex post-transcriptional control. Examining homoeologous genes with a 1:1:1 relationship across the A, B, and D genomes (triads), we revealed a complex genomic architecture for drought responses under field conditions, involving gene homoeolog specialization, multiple gene clusters, gene families, miRNAs, and transcription factors coordinating these responses. Our results provide a new focus for genomics-assisted breeding of drought-tolerant wheat cultivars.This work was funded by project P12-AGR-0482 from Junta de Andalucía, Spain (Co-funded by FEDER); projects BIO2011-15237-E, AGL2016-77149-C2-1-P, and CGL2016-79790-P from MINECO (Spanish Ministry of Economy, Industry and Competitiveness); UK Biotechnology and Biological Sciences Research Council (BBSRC) through Designing Future Wheat (BB/P016855/1), GEN (BB/P013511/1), and an Anniversary Future Leaders Fellowship to PB (BB/M014045/1). HB was supported by the Montana Plant Science Endowment fund.Peer reviewe