Laurent Laplaze

Laurent Laplaze
Institute of Research for Development | IRD · 232 - Diversity, Adaptation and Development of Cultivated Plants (DIADE)

PhD

About

209
Publications
70,200
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
8,740
Citations
Introduction
My research focuses on plant root system development and interaction with symbiotic microorganisms. The experimental models I study are lateral root development in the model plant Arabidopsis thaliana, crown and lateral root development, rhizosheath formation as well as mycorhizal symbioses in two important cereals (rice and pearl millet).
Additional affiliations
September 2010 - present
Institute of Research for Development
Position
  • Adaptative root development
September 2001 - present
Institute of Research for Development
Position
  • Adaptative root development
September 1999 - August 2001
University of Cambridge
Position
  • Molecular genetics of root development in Arabidopsis

Publications

Publications (209)
Chapter
Etablissement des symbioses actinorhiziennes: évènements cellulaires, physiologiques et moléculaires des différentes étapes des symbioses actinorhiziennes
Article
Full-text available
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 cha...
Article
In cereals, the root system is mainly composed of postembryonic shoot borne roots, named crown roots. The CROWN ROOTLESS1 (CRL1) transcription factor belonging to the ASYMMETRIC LEAVES2‐LIKE/LATERAL ORGAN BOUNDARIES DOMAIN (ASL/LBD) family is a key regulator of crown root initiation in rice. Here, we show that CRL1 can bind, both in vitro and in vi...
Article
Improving crop water use efficiency, the amount of carbon assimilated as biomass per unit of water used by a plant, is of major importance as water for agriculture becomes scarcer. In rice, the genetic bases of transpiration efficiency, the derivation of water use efficiency at the whole-plant scale, and its putative component trait transpiration r...
Article
Highlight Consistent with the hypothesis that mutual inhibition between gene regulatory sub-networks contributes to lateral root formation, we show that PUCHI represses early meristematic gene expression in developing root primordia. Abstract Lateral root organogenesis is a key process in the development of a plant's root system and its adaptatio...
Article
In Africa, agriculture is largely based on low-input and small-holder farming systems that use little inorganic fertilizers and have limited access to irrigation and mechanization. Improving agricultural practices and developing new cultivars adapted to these environments, where production already suffers from climate change, is a major priority fo...
Article
Full-text available
Fungal communities associated with roots play a key role in nutrient uptake and in mitigating the abiotic and biotic stress of their host. In this study, we characterized the roots mycobiome of wild and cultivated pearl millet [ Pennisetum glaucum (L.) R. Br., synonym: Cenchrus americanus (L.) Morrone] in three agro-ecological areas of Senegal foll...
Chapter
Postembryonic organogenesis is a critical component in plant root and shoot development and its adaptation to the environment. Decades of scientific analyses have yielded a wealth of experimental data about the cellular and molecular processes orchestrating the postembryonic formation of new shoot and root organs. Among these, distribution and sign...
Chapter
A method has been developed to measure root intersection density (RID) on a trench-profile in field conditions. Here we describe how 2D spatial distribution mapping of RID can be processed and converted into root length density (RLD) and root distances (ARD) using a new freeware named RACINE2.2. The software also allows a simple modeling of potenti...
Book
Postembryonic organogenesis is a critical component in plant root and shoot development and its adaptation to the environment. Decades of scientific analyses have yielded a wealth of experimental data about the cellular and molecular processes orchestrating the postembryonic formation of new shoot and root organs. Among these, distribution and sign...
Book
A method has been developed to measure root intersection density (RID) on a trench-profile in field conditions. Here we describe how 2D spatial distribution mapping of RID can be processed and converted into root length density (RLD) and root distances (ARD) using a new freeware named RACINE2.2. The software also allows a simple modeling of potenti...
Preprint
Full-text available
Because water availability is the most important environmental factor limiting crop production, improving water use efficiency, the amount of carbon fixed per water used, is a major target for crop improvement. In rice, the genetic bases of transpiration efficiency, the derivation of water use efficiency at the whole-plant scale, and its putative c...
Preprint
Full-text available
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 cha...
Preprint
In Africa, agriculture is largely based on low-input and small-holder farming systems that use little inorganic fertilizers and have limited access to irrigation and mechanization. Improving agricultural practices and developing new cultivars adapted to these low-input environments, where production already suffers from climate change, is a major p...
Article
Full-text available
Aims: The interactions between plant roots and the associated microbiota impact soil aggregation, water retention and plant nutrient availability. Thus, selection of plant genotypes that promote microbial species involved in root-adhering soil aggregation and rhizosheath formation could help improve yield sustainably. Here, we tested pearl millet g...
Preprint
Full-text available
In Africa, agriculture is largely based on low-input and small-holder farming systems that use little inorganic fertilizers and have limited access to irrigation and mechanization in comparison to modern agricultural systems. Improving agricultural practices and developing new cultivars adapted to these low-input environments, where production alre...
Article
Full-text available
Pearl millet (Pennisetumglaucum (L.) R. Br) is a cereal grown in the driest tropical and subtropical regions of Africa and Asia. Thanks to its strong capacity to adapt to the dry tropical climate and low fertility soils, millet plays an important role in the food security of local populations in these regions. It is able to establish a mycorrhizal...
Article
Full-text available
Crown roots constitute the main part of the rice root system. Several key genes involved in crown root initiation and development have been identified by functional genomics approaches. Nevertheless, these approaches are impaired by functional redundancy and mutant lethality. To overcome these limitations, organ targeted transcriptome analysis can...
Article
Full-text available
Background First discovered on desert plants by Volkens 1887, rhizosheath formation, i.e. soil aggregation at the root surface, is now considered as a very promising adaptive trait to deal with abiotic stress. Indeed, the rhizosheath could help plants better cope with water stress, nitrogen and phosphorus deficiencies, and soil acidity. Scope We h...
Article
Full-text available
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 relating to conservation of soil water or increased water use efficiency can alleviate that stress. Aquaporins (AQP) are water channels that mediate root water transport, thereby influencing...
Article
Full-text available
Land salinization is a major constraint for the practice of agriculture in the world. Considering the extent of this phenomenon, the rehabilitation of ecosystems degraded by salinization has become a priority to guarantee food security in semi-arid environments. The mechanical and chemical approaches for rehabilitating salt-affected soils being exp...
Preprint
Full-text available
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 invol...
Article
Full-text available
Plants forage soil for water and nutrients, whose distribution is patchy and often dynamic. To improve their foraging activities, plants have evolved mechanisms to modify the physicochemical properties and microbial communities of the rhizosphere, i.e. the soil compartment under the influence of the roots. This dynamic interplay in root‐soil‐microb...
Article
Heavy metal contamination is of particular concern for human health and the environment. Phytoremediation is an emerging cost-effective strategy to remediate heavy metal contaminated soil. However, this technique is limited by the small number of plants that are tolerant to heavy metals and are also accumulators. This study assayed zinc, lead, and...
Chapter
Phytohormones play a crucial role in regulating plant developmental processes. Among them, ethylene and jasmonate are known to be involved in plant defense responses to a wide range of biotic stresses as their levels increase with pathogen infection. In addition, these two phytohormones have been shown to inhibit plant nodulation in legumes. Here,...
Book
This second edition volume expands on the previous edition with a look at the latest techniques used to study plant hormone jasmonate (JA). The chapters in this book are organized into three parts: Parts One and Two discuss the role of JA in plant physiology and development, and in plant-biotic interactions. Part Three talks about methods used by r...
Book
Phytohormones play a crucial role in regulating plant developmental processes. Among them, ethylene and jasmonate are known to be involved in plant defense responses to a wide range of biotic stresses as their levels increase with pathogen infection. In addition, these two phytohormones have been shown to inhibit plant nodulation in legumes. Here,...
Article
Crown roots (CRs) are essential components of the rice root system. Several genes involved in CR initiation or development have been indentified but our knowledge about how they organize to form a gene regulatory network (GRN) is still limited. To characterize the regulatory cascades acting during CR formation, we used a systems biology approach to...
Article
Full-text available
Pearl millet is able to withstand dry and hot conditions and plays an important role for food security in arid and semi-arid areas of Africa and India. However, low soil fertility and drought constrain pearl millet yield. One target to address these constraints through agricultural practices or breeding is root system architecture. In this study, i...
Article
Lateral roots (LRs) are crucial for increasing the surface area of root systems to explore heterogeneous soil environments. Major advances have recently been made in the model plant arabidopsis (Arabidopsis thaliana) to elucidate the cellular basis of LR development and the underlying gene regulatory networks (GRNs) that control the morphogenesis o...
Article
Lateral root organogenesis plays an essential role in elaborating plant root system architecture. In Arabidopsis , the AP2 family transcription factor PUCHI controls cell proliferation in lateral root primordia. To identify potential targets of PUCHI, we analyzed a time course transcriptomic dataset of lateral root formation. We report that multipl...
Preprint
Full-text available
Pearl millet, unlike other cereals, is able to withstand dry and hot conditions and plays an important role for food security in arid and semi-arid areas of Africa and India. However, low soil fertility and drought constrain pearl millet yield. One of the main targets to address these constraints through agricultural practices or breeding is root s...
Article
Full-text available
Actinorhizal plants form a symbiotic association with the nitrogen-fixing actinobacteria Frankia. These plants have important economic and ecological benefits including land reclamation, soil stabilization, and reforestation. Recently, many non-Frankia actinobacteria have been isolated from actinorhizal root nodules suggesting that they might contr...
Conference Paper
Full-text available
In West Africa, farmers used pearl millet diversity to cope with climate change impact on rainfall distribution and water scarcity. However, in this selection-based adaptation, the interactions between the plant roots and rhizo-microbial communities were not taken in account. Indeed, these interactions that involve carbon root exudation in the rhiz...
Article
Full-text available
Pearl millet plays a major role in food security in arid and semi-arid areas of Africa and India. However, it lags behind the other cereal crops in terms of genetic improvement. The recent sequencing of its genome opens the way to the use of modern genomic tools for breeding. Our study aimed at identifying genetic components involved in early droug...
Poster
Full-text available
Crop inoculation with beneficial soil microbes has been proposed as an sustainable alternative to agro-chemicals. However, use of inoculation requires selecting optimal combinations of crop varieties and associated microbes to increase the efficiency of production systems. We previously showed that rice response to microbial inoculation was depende...
Chapter
The complex and adaptable architecture of the plant root system in soil is of paramount importance for crop growth and performance. Root growth depends on the activity of the root apical meristem, an organised population of proliferating progenitor cells continuously replenished from a stem cell niche. Root branching, which greatly contributes to r...
Article
Actinorhizal plants form a symbiotic association with the nitrogen-fixing actinobacteria Frankia. These plants have important economic and ecological benefits including land reclamation, soil stabilization, and reforestation. Recently, many non- Frankia actinobacteria have been isolated from actinorhizal root nodules suggesting that they might cont...
Article
Full-text available
- Key message Selection of the best salt-tolerant combination of Casuarina sp. and arbuscular mycorrhizal fungi (AMF) is one of the key criteria for successful setup of saline land rehabilitation program. - Context Land salinization is a serious problem worldwide that mainly leads to soil degradation and reduces crop productivity. These degraded ar...
Article
Rice is one of the most consumed crop around the globe and its production needs to be increased in a context of climate change and water scarcity. Rice roots, as most land plants, can establish symbiotic association with arbuscular mycorrhizal fungi (AMF). Rice has emerged, in the past decade, as a model to study the molecular determinants of AM sy...
Preprint
Full-text available
Pearl millet plays a major role in food security in arid and semi-arid areas of Africa and India. However, it lags behind the other cereal crops in terms of genetic improvement. The recent sequencing of its genome opens the way to the use of modern genomic tools for breeding. Our study aimed at identifying genetic components involved in early droug...
Article
Full-text available
Recent progress in root phenotyping has focused mainly on increasing throughput for genetic studies while identifying root developmental patterns has been comparatively underexplored. We introduce a new phenotyping pipeline for producing high-quality spatio-temporal root system development data and identifying developmental patterns within these da...
Article
Pearl millet is an important cereal for food security in the arid regions of Africa and India. The recently published genome of this tough cereal crop has shed new light on its history and adaptation to dry, hot climates and paves the way for much-needed genomic-based breeding efforts.
Article
Full-text available
The overuse of agricultural chemicals such as fertilizer and pesticides aimed at increasing crop yield results in environmental damage, particularly in the Sahelian zone where soils are fragile. Crop inoculation with beneficial soil microbes appears as a good alternative for reducing agricultural chemical needs, especially for small farmers. This,...
Data
Root length and frequency of colonization of inoculated plants of O. sativa var. Sahel 202 for the 1st and 2nd-year trials. In each column, means followed by the same letter are not significantly different at P≤0.05. (PDF)
Data
Height of non-inoculated and inoculated plants of O. sativa Sahel 202. A single microbial strain (AMF or PGPR, A), two strains (B), and 3 and 4 strains (C), were used in the 1st year (A1, B1 and C1) and 2nd year (A2, B2 and C2) trials. Ri: Rhizophagus irregularis; Ga: Glomus aggregatum; ORS 278: Bradyrhizobium sp. ORS 278; and ORS 3454: Leifsonia s...
Data
Student’s t-test for the ln (x +10) transformed values of agronomic traits in rice plants at variety level. AM: inoculated with AMF and NM: non-inoculated. Abbreviations associated to the variety names indicate the rice ecotype (Upl: Upland, Irr: Irrigated, Rll: Rainfed lowland). (PDF)
Data
ANOVA for the ln (x +10) transformed values of agronomic traits in rice plants at ecotype level. AMF inoculation (inoculated and non-inoculated), ecotype (upland, irrigated and rainfed lowland) and year (1st and 2nd-year trial). (PDF)
Data
ANOVA for the ln (x +10) transformed values of agronomic traits in rice plants at variety level. AMF inoculation (inoculated and non-inoculated), variety (each of the 8 varieties tested) and year (1st and 2nd-year trial). (PDF)
Data
Collar section growth curves of non-inoculated and inoculated plants of O. sativa Sahel 202. A single microbial strain (AMF or PGPR, D1 and D2), two strains (E1 and E2), and 3 and 4 strains (F1 and F2), were used in the 1st year (D1, E1 and F1) and 2nd year (D2, E2 and F2) trials. Ri: Rhizophagus irregularis; Ga: Glomus aggregatum; ORS 278: Bradyrh...
Data
Student’s t-test for the ln (x +10) transformed values of agronomic traits in rice plants at ecotype level. AM: inoculated with AMF and NM: non-inoculated. (PDF)
Article
Full-text available
Soil salinization is a major threat to agriculture in arid and semi-arid regions, where water scarcity and inadequate drainage of irrigated lands severely reduce crop yield. Salt accumulation inhibits plant growth and reduces the ability to uptake water and nutrients, leading to osmotic or water-deficit stress. Salt is also causing injury of the yo...
Conference Paper
Full-text available
Introduction: The molecular mechanisms controlling crown root formation is not well understood. The crown root less 1 (crl1) mutant is devoid of crown root. The CRL1 gene encodes a plant specific LBD transcription factor. In order to identify CRL1 target genes, a transcriptomic study was carried out using the inducible expression of CRL1 in the crl...
Article
Full-text available
Symbiotic nitrogen-fixing associations between Casuarina trees and the actinobacteria Frankia are widely used in agroforestry in particular for salinized land reclamation. The aim of this study was to analyze the effects of salinity on the establishment of the actinorhizal symbiosis between C. glauca and two contrasting Frankia strains (salt sensit...
Article
Full-text available
Lateral root (LR) formation is an important determinant of root system architecture. In Arabidopsis, LRs originate from pericycle cells, which undergo a programme of morphogenesis to generate a new LR meristem. Despite its importance for root meristem organisation, the onset of organizing center (termed quiescent center; QC) formation during LR mor...
Article
Full-text available
Pearl millet plays an important role for food security in arid regions of Africa and India. Nevertheless, it is considered an orphan crop as it lags far behind other cereals in terms of genetic improvement efforts. Breeding pearl millet varieties with improved root traits promises to deliver benefits in water and nutrient acquisition. Here, we char...
Poster
Full-text available
La production de riz au Sénégal fait face à des contraintes liées aux changements climatiques telles que le déficit hydrique. A cela s’ajoute la baisse de la fertilité des sols consécutive aux prélèvements de grandes quantités de nutriments des sols. Les effets isolés ou conjugués de ces contraintes limitent la productivité des écosystèmes rizicole...
Article
Full-text available
Frankia is a soil actinomycete that forms nitrogen-fixing root nodule symbioses with eight angiosperms families including Casuarinaceae. Knowledge on symbiotic performance of several isolated strains with Casuarina species is limited. In this study, we characterized a collection of Frankia strains based on their growth kinetics and their symbiotic...
Article
Full-text available
Environmental stresses are caused by human activities or natural events. Several of them including salinity, heavy metals, and extreme temperature affect both soil characteristics and plant growth and productivity. Actinorhizal plants are pioneer species that are able to grow in poor soils and improve soil fertility. They are widely used in agrofor...