Biology subjects

de la Fuente Canto, C.

Publications and source records attributed to de la Fuente Canto, C..

3 recordsLinked to original sources

bioRxiv2023

Glutaredoxin regulation of primary root growth confers early drought stress tolerance in pearl millet

Seedling root traits impact plant establishment under challenging environments. Pearl millet is one of the most heat and drought tolerant cereal crops that provides a vital food source across the sub-Saharan Sahel region. Pearl millets early root system features a single fast-growing primary root which we hypothesize is an adaptation to the Sahelian climate. Using crop modelling, we demonstrate that early drought stress is an important constraint in agrosystems in the Sahel where pearl millet was domesticated. Furthermore, we show that increased pearl millet primary root growth is correlated with increased early water stress tolerance in field conditions. Genetics including GWAS and QTL approaches identify genomic regions controlling this key root trait. Combining gene expression data, re-sequencing and re-annotation of one of these genomic regions identified a glutaredoxin-encoding gene PgGRXC9 as the candidate stress resilience root growth regulator. Functional characterization of its closest Arabidopsis homolog AtROXY19 revealed a novel role for this glutaredoxin (GRX) gene clade in regulating cell elongation. In summary, our study suggests a conserved function for GRX genes in conferring root cell elongation and enhancing resilience of pearl millet to its Sahelian environment.

plant biology↗

bioRxiv2021

Genetic control of rhizosheath formation in pearl millet

The rhizosheath, the layer of soil that adheres strongly to roots, influences water and nutrients acquisition. Pearl millet is a cereal crop that plays a major role for food security in arid regions of sub Saharan Africa and India. We previously showed that root-adhering soil mass is a heritable trait in pearl millet and that it correlates with changes in rhizosphere microbiota structure and functions. Here, we studied the correlation between root-adhering soil mass and root hair development, root architecture, and symbiosis with arbuscular mycorrhizal fungi and we analysed the genetic control of this trait using genome wide association (GWAS) combined with bulk segregant analysis and gene expression studies. Root-adhering soil mass was weakly correlated only to root hairs traits in pearl millet. Twelve QTLs for rhizosheath formation were identified by GWAS. Bulk segregant analysis on a biparental population validated five of these QTLs. Combining genetics with a comparison of global gene expression in the root tip of contrasted inbred lines revealed candidate genes that might control rhizosheath formation in pearl millet. Our study indicates that rhizosheath formation is under complex genetic control in pearl millet and suggests that it is mainly regulated by root exudation. HighlightFormation of the rhizosheath, a layer of soil adhering to the root, is under complex genetic control in pearl millet and is mainly regulated by root exudation.

plant biology↗

bioRxiv2020

Aquaporins are main contributors of root hydraulic conductivity in pearl millet

Pearl millet is a key cereal for food security in arid and semi-arid regions but its yield is increasingly threatened by water stress. Physiological mechanisms consisting in saving water or increasing water use efficiency can alleviate that stress. Aquaporins (AQP) are water channels contributing to plant hydraulic balance that are supposedly involved in these mechanisms by mediating root water transport. However, AQP remain largely uncharacterized in pearl millet. Here, we studied AQP function in root water transport in two pearl millet lines contrasting for water use efficiency (WUE). We observed that these lines were also contrasting for root hydraulic conductivity (Lpr) and AQP contribution to Lpr, the line with lower WUE showing significantly higher AQP contribution to Lpr. To investigate the AQP isoforms contributing to Lpr, we developed genomic approaches to first identify the entire AQP family in pearl millet and second study the plasma membrane intrinsic proteins (PIP) gene expression profile. We identified and annotated 33 AQP genes in pearl millet among which ten encoded PIP isoforms. PgPIP1-3 and PgPIP1-4 were significantly more expressed in the line showing lower WUE, higher Lpr and higher AQP contribution to Lpr. Overall, our study suggests that AQP from the PIP1 family are the main contributor of Lpr in pearl millet and are possibly associated to whole plant water use mechanisms. This study paves the way for further investigations on AQP functions in pearl millet hydraulics and adaptation to environmental stresses. The newly sequenced nucleotide sequences reported in this article have been submitted to GenBank under the submission number 2333840 (TPA grp467567). Assignment of GenBank accession number is in process.

plant biology↗