Biology subjects

Santiago, R.

Publications and source records attributed to Santiago, R..

3 recordsLinked to original sources

bioRxiv2025

Genotype-Dependent Response to Water Deficit: Increases in Maize Cell Wall Digestibility Occurs Through Reducing Both p-Coumaric Acid and Lignification of the Rind

The compositional dynamics of the cell wall are influenced by drought, and it has been demonstrated that water deficit induces significant changes in its main components. Moreover, changes in cell wall concentration and distribution in response to water deficit affect maize degradability. This study presents a histological and biochemical analysis of thirteen maize inbred lines, evaluated over two years in Pobra de Brollon (Spain) and Mauguio (France) under contrasting water availability conditions. Our aim was to investigate the environmental and genotypic impacts on histological and biochemical profiles, to assess in vitro cell wall digestibility under water deficit, and to explore how these responses relate to changes in cell wall composition and structure. Overall, we observed greater concentrations of p-coumaric acid under control conditions, with significant decreases in stressed conditions at each location. Histologically, we found an increase in non-lignified tissues under water deficit conditions across all tissues and in both locations. In terms of in vitro cell wall digestibility (IVCWRD), significant increases were detected in response to water deficit. Additionally, genotype-dependent response patterns were evident, revealing two distinct behavioural groups. Notably, in plastic genotypes, increases in IVCWRD in response to water deficit were concomitant to reductions in p-coumaric acid content and a decrease in red-stained lignified tissues in the rind. This study emphasizes the complex, genotype-dependent responses to water deficit, underscoring the important roles of plasticity and stability in shaping the impact on maize cell wall digestibility; paving the way to breed for adapted genotypes to face climate changes. HighlightIncreased digestibility in response to water deficit is genotype-dependent and linked to reductions in p-coumaric acid content and lower lignification of the rind

physiology↗

bioRxiv2024

Long-distance gene flow and recombination shape the evolutionary history of a maize pathogen

The evolutionary history of crop pathogens is shaped by a complex interaction of natural and anthropogenic factors. The ascomycete fungus Colletotrichum graminicola causes maize anthracnose. The disease can result in significant yield losses and is also an important model for genetic studies. We conducted a comprehensive investigation into the evolutionary genomics of C. graminicola using a collection of 212 isolates from 17 countries. Genomic analyses supported the existence of three geographically isolated genetic lineages, with a significant pattern of isolation by distance. We identified two distinct gene flow patterns, driven by short and long-distance dispersion, likely resulting from the natural spread of the pathogen and the exchange of contaminated seeds. We present evidence of genetic introgression between lineages, suggesting a long history of recombination. We identified significant recombination events coalescing at distinct points in time, with the North American lineage displaying evidence of most ancient recombination. Demographic modeling indicated that North America is an intermediate between Brazil, Europe and an ancestral, unsampled source population, hypothesized to be Mesoamerican. Our analyses revealed that the global genomic structure of C. graminicola is shaped by geographic differentiation driven by long-distance migration and a long history of recombination and introgression. We show historical relationships among these lineages, identifying a potential route for fungal spread, with the North American population emerging ancestrally, followed sequentially by the Brazilian and European populations. Our research indicates that the European lineage is more virulent, which has implications for the potential emergence of new outbreaks of maize anthracnose in Europe.

genomics↗

bioRxiv2024

Citizen Science Data on Urban Forageable Plants: A Case Study in Brazil

This paper presents two key data sets derived from the Pomar Urbano project. The first data set is a comprehensive catalog of edible fruit-bearing plant species, native or introduced in Brazil. The second data set, sourced from the iNaturalist platform, tracks the distribution and monitoring of these plants within urban landscapes across Brazil. The study encompasses data from all 27 Brazilian state capitals, focusing on the ten cities that contributed the most observations as of August 2023. The research emphasizes the significance of citizen science in urban biodiversity monitoring and its potential to contribute to various fields, including food and nutrition, creative industry, study of plant phenology, and machine learning applications. We expect the data sets to serve as a resource for further studies in urban foraging, food security, cultural ecosystem services, and environmental sustainability.

plant biology↗