scholarly journals Genetic control of rhizosheath formation in pearl millet

2021 ◽  
Author(s):  
Carla de la Fuente Canto ◽  
Marcel Nahim Diouf ◽  
Papa Mamadou Sitor Ndour ◽  
Marilyne Debieu ◽  
Alexandre Grondin ◽  
...  
Keyword(s):  
Gene Expression ◽  
Genetic Control ◽  
Pearl Millet ◽  
Mycorrhizal Fungi ◽  
Bulk Segregant Analysis ◽  
Root Exudation ◽  
Root Hairs ◽  
Soil Mass ◽  
Sub Saharan Africa ◽  
Root Tip

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 and bulk segregant analysis on a biparental population further 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.

scholarly journals Supra-physiological levels of Gibberellins/DELLAs alter the patterning, morphology and abundance of root hairs in root tips of A. thaliana seedlings

2021 ◽  
Author(s):  
Iva McCarthy-Suarez
Keyword(s):  
Gene Expression ◽  
Cell Fate ◽  
Epidermal Cell ◽  
Root Hair ◽  
Root Hairs ◽  
Root Tip ◽  
Spatial Patterning ◽  
Root Tips ◽  
Root Epidermis

In spite of the known role of gibberellins (GAs), and of their antagonistic proteins, the DELLAs, in leaf hair production, no investigations, however, have assessed their hypothetical function in the production of root hairs. To this aim, the effects of supra-physiological levels of GAs/DELLAs on the spatial patterning of gene expression of the root hair (CPC) and root non-hair (GL2, EGL3 and WER) epidermal cell fate markers, as well as on the distribution, morphology and abundance of root hairs, were studied in root tips of 5-day-old A. thaliana seedlings. Results showed that excessive levels of GAs/DELLAs impaired the spatial patterning of gene expression of the root hair/non-hair epidermal cell fate markers, as well as the arrangement, shape and frequency of root hairs, giving rise to ectopic hairs and ectopic non-hairs, two-haired cells, two-tipped hairs, branched hairs, longer and denser hairs near the root tip under excessive DELLAs, and shorter and scarcer hairs near the root tip under excessive GAs. However, when the gai-1 (GA-insensitive-1) DELLA mutant protein was specifically over-expressed at the root epidermis, no changes in the patterning or abundance of root hairs occurred. Thus, these results suggest that, in seedlings of A. thaliana, the GAs/DELLAs might have a role in regulating the patterning, morphology and abundance of root hairs by acting from the sub-epidermal tissues of the root.

scholarly journals Germinating Spore Exudates from Arbuscular Mycorrhizal Fungi: Molecular and Developmental Responses in Plants and Their Regulation by Ethylene

2011 ◽  
Vol 24 (2) ◽  
pp. 260-270 ◽  
Author(s):  
Arijit Mukherjee ◽  
Jean-Michel Ané
Keyword(s):  
Gene Expression ◽  
Genetic Control ◽  
Root Development ◽  
Mycorrhizal Fungi ◽  
Root Architecture ◽  
Glomus Intraradices ◽  
Arbuscular Mycorrhizal ◽  
Am Fungi ◽  
Plant Responses ◽  
Symbiotic Gene

Arbuscular mycorrhizal (AM) fungi stimulate root development and induce expression of mycorrhization-specific genes in both eudicots and monocots. Diffusible factors released by AM fungi have been shown to elicit similar responses in Medicago truncatula. Colonization of roots by AM fungi is inhibited by ethylene. We compared the effects of germinating spore exudates (GSE) from Glomus intraradices in monocots and in eudicots, their genetic control, and their regulation by ethylene. GSE modify root architecture and induce symbiotic gene expression in both monocots and eudicots. The genetic regulation of root architecture and gene expression was analyzed using M. truncatula and rice symbiotic mutants. These responses are dependent on the common symbiotic pathway as well as another uncharacterized pathway. Significant differences between monocots and eudicots were observed in the genetic control of plant responses to GSE. However, ethylene inhibits GSE-induced symbiotic gene expression and root development in both groups. Our results indicate that GSE signaling shares similarities and differences in monocots versus eudicots, that only a subset of AM signaling pathways has been co-opted in legumes for the establishment of root nodulation with rhizobia, and that regulation of these pathways by ethylene is a feature conserved across higher land plants.

scholarly journals Remodeling of root morphology by CuO and ZnO nanoparticles: effects on drought tolerance for plants colonized by a beneficial pseudomonad

Botany ◽  
2018 ◽  
Vol 96 (3) ◽  
pp. 175-186 ◽  
Author(s):  
Kwang-Yeol Yang ◽  
Stephanie Doxey ◽  
Joan E. McLean ◽  
David Britt ◽  
Andre Watson ◽  
...  
Keyword(s):  
Calcareous Soils ◽  
Root Hairs ◽  
Triticum Aestivum L ◽  
Metal Stress ◽  
Root Tip ◽  
Zno Nps ◽  
Wheat Seedlings ◽  
Cuo Nps ◽  
Expression Of Genes ◽  
Induced Tolerance

Formulations that include nanoparticles of CuO and ZnO are being considered for agricultural applications as fertilizers because they act as sources of Cu or Zn. Currently, few studies of the effects of these nanoparticles (NPs) consider the three-way interactions of NPs with the plant plus its microbiome. At doses that produced root shortening by both nanoparticles (NPs), CuO NPs induced the proliferation of elongated root hairs close to the root tip, and ZnO NPs increased lateral root formation in wheat seedlings (Triticum aestivum L.). These responses occurred with roots colonized by a beneficial bacterium, Pseudomonas chlororaphis O6 (PcO6), originally isolated from roots of wheat grown under dryland farming in calcareous soils. The PcO6-induced tolerance to drought stress in wheat seedlings was not impaired by the NPs. Rather, growth of the PcO6-colonized plants with NPs resulted in systemic increases in the expression of genes associated with tolerance to water stress. Increased expression in the shoots of other genes related to metal stress was consistent with higher levels of Cu and Zn in PcO6-colonized shoots grown with the NPs. This work demonstrates that plants grown with CuO or ZnO NPs showed cross-protection from different challenges such as metal stress and drought.

scholarly journals Genetic control of gene expression in whole blood and lymphoblastoid cell lines is largely independent

2011 ◽  
Vol 22 (3) ◽  
pp. 456-466 ◽  
Author(s):  
J. E. Powell ◽  
A. K. Henders ◽  
A. F. McRae ◽  
M. J. Wright ◽  
N. G. Martin ◽  
...  
Keyword(s):  
Gene Expression ◽  
Genetic Control ◽  
Cell Lines ◽  
Whole Blood ◽  
Lymphoblastoid Cell Lines ◽  
Control Of Gene Expression

Effects of temperature rise (+5°C) on millet growth and mycorrhization and soil microbial community of culture

2021 ◽  
Author(s):  
Sally Diatta ◽  
Hassna Mboup-Founoune ◽  
Sidy Diakhaté ◽  
Diégane Diouf
Keyword(s):  
Microbial Community ◽  
Arbuscular Mycorrhizal Fungi ◽  
Mycorrhizal Fungi ◽  
Crop Yields ◽  
Pennisetum Glaucum ◽  
Agricultural Practices ◽  
Arbuscular Mycorrhizal ◽  
Sub Saharan Africa ◽  
Soil Fertility Management ◽  
Vegetation Growth

<p>Our planet is marked by significant climatic variations, particularly with the warming of temperatures and the variation in rainfall. In sub-Saharan Africa, the impacts of climate change are more pronounced because agriculture is highly dependent on climate, hence its vulnerability to climate variability (Vanluwe et al., 2011). In the context of changing environmental conditions, the use of innovative agricultural practices to contribute to plant adaptation is necessary to support food security challenges. Agroecological practices to improve crop yields and sustainable soil fertility management. Soil is the main reservoir of biodiversity as it hosts a very high diversity of interacting living species, which can be distinguished according to their size, macrofauna, mesofauna and microorganisms that constitute a particularly important component of soil (Brady and Weil, 2002), particularly for the provision of ecosystem services to humans. This work is therefore interested in studying the contribution of arbuscular mycorrhizal fungi (AMF) to the growth of millet (<em>Pennisetum glaucum</em>) under warmer temperature conditions and the behaviour of microbial community in soil of millet growing.</p><p>Millet is grown in a plant climate chamber and inoculated with a selected mycorrhizal strain.  These millet growing conditions were carried out in two different temperatures: 32°C (normal temperature) and 37°C (warmer temperature).</p><p>The results showed that in conditions of warmer temperature the inoculation induced a significant vegetative growth of millet even with a low intensity of mycorrhization and so it improves microbial nutrient mineralization mediate vegetation growth.</p><p>In soil of millet growing, a significant increase in microbial biomass with 42.7 in warmer temperature condition compared to control temperature 16.7. Results of DGGE shows also a soil abundance and SMB diversity of the total fungal community was noted under warmer temperature condition.</p><p>This study showed that climate variation may affect soil symbiosis but not the potential for promoting plant growth of fungi. The use of arbuscular mycorrhizal fungi on the one hand as a biofertilizer can be an alternative in the context of reducing chemical inputs in agriculture and developing ecologically intensive agriculture (EIA) and on the other hand an adaptive practice  to apprehend the predicted climate changes.</p>

scholarly journals Genetic Gains in Pearl Millet in India: Insights Into Historic Breeding Strategies and Future Perspective

2021 ◽  
Vol 12 ◽  
Author(s):  
Om Parkash Yadav ◽  
S. K. Gupta ◽  
Mahalingam Govindaraj ◽  
Rajan Sharma ◽  
Rajeev K. Varshney ◽  
...  
Keyword(s):  
Pearl Millet ◽  
Pennisetum Glaucum ◽  
Sub Saharan Africa ◽  
Hybrid Breeding ◽  
Future Perspective ◽  
Yield Increase ◽  
Genetic Gains ◽  
Parental Lines ◽  
Sub Saharan ◽  
Periodic Replacement

Pearl millet (Pennisetum glaucum R. Br.) is an important staple and nutritious food crop in the semiarid and arid ecologies of South Asia (SA) and Sub-Saharan Africa (SSA). In view of climate change, depleting water resources, and widespread malnutrition, there is a need to accelerate the rate of genetic gains in pearl millet productivity. This review discusses past strategies and future approaches to accelerate genetic gains to meet future demand. Pearl millet breeding in India has historically evolved very comprehensively from open-pollinated varieties development to hybrid breeding. Availability of stable cytoplasmic male sterility system with adequate restorers and strategic use of genetic resources from India and SSA laid the strong foundation of hybrid breeding. Genetic and cytoplasmic diversification of hybrid parental lines, periodic replacement of hybrids, and breeding disease-resistant and stress-tolerant cultivars have been areas of very high priority. As a result, an annual yield increase of 4% has been realized in the last three decades. There is considerable scope to further accelerate the efforts on hybrid breeding for drought-prone areas in SA and SSA. Heterotic grouping of hybrid parental lines is essential to sustain long-term genetic gains. Time is now ripe for mainstreaming of the nutritional traits improvement in pearl millet breeding programs. New opportunities are emerging to improve the efficiency and precision of breeding. Development and application of high-throughput genomic tools, speed breeding, and precision phenotyping protocols need to be intensified to exploit a huge wealth of native genetic variation available in pearl millet to accelerate the genetic gains.

scholarly journals Effects of Laccaria bicolor on Gene Expression of Populus trichocarpa Root under Poplar Canker Stress

2021 ◽  
Vol 7 (12) ◽  
pp. 1024
Author(s):  
Fengxin Dong ◽  
Yihan Wang ◽  
Ming Tang
Keyword(s):  
Gene Expression ◽  
Disease Resistance ◽  
Plant Disease Resistance ◽  
Mycorrhizal Fungi ◽  
Populus Trichocarpa ◽  
Gene Expression Pattern ◽  
Oxygen Metabolism ◽  
Resistance Response ◽  
Expression Of Genes ◽  
Plant Pathogen Interaction

Poplars can be harmed by poplar canker. Inoculation with mycorrhizal fungi can improve the resistance of poplars to canker, but the molecular mechanism is still unclear. In this study, an aseptic inoculation system of L. bicolor–P. trichocarpa–B. dothidea was constructed, and transcriptome analysis was performed to investigate regulation by L. bicolor of the expression of genes in the roots of P. trichocarpa during the onset of B. dothidea infection, and a total of 3022 differentially expressed genes (DEGs) were identified. Weighted correlation network analysis (WGCNA) was performed on these DEGs, and 661 genes’ expressions were considered to be affected by inoculation with L. bicolor and B. dothidea. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses showed that these 661 DEGs were involved in multiple pathways such as signal transduction, reactive oxygen metabolism, and plant-pathogen interaction. Inoculation with L. bicolor changed the gene expression pattern of the roots, evidencing its involvement in the disease resistance response of P. trichocarpa. This research reveals the mechanism of L. bicolor in inducing resistance to canker of P. trichocarpa at the molecular level and provides a theoretical basis for the practical application of mycorrhizal fungi to improve plant disease resistance.

Advances in understanding plant root hairs in relation to nutrient acquisition and crop root function

2021 ◽  
pp. 127-162
Author(s):  
Timothy S. George ◽  
◽  
Lawrie K. Brown ◽  
A. Glyn Bengough ◽  
◽  
...  
Keyword(s):  
Plant Root ◽  
Root Hairs ◽  
Microbial Interactions ◽  
Flowering Plant ◽  
Agricultural Sustainability ◽  
Root Tip ◽  
Pattern Length ◽  
Crop Root ◽  
Flowering Plant Species ◽  
And Function

Root hairs are found on most terrestrial flowering plant species. They form from epidermal cells at a predetermined distance behind the growing root tip in three main patterns. Their presence, pattern, length, density and function are genetically controlled and numerous genes are expressed solely in root hairs. Their growth and proliferation are attenuated by the environment and root hairs growing in soil are generally shorter and less dense than those in laboratory studies. Root hairs have a number of functions including anchorage, root soil contact and bracing to enable roots to penetrate hard soils. However, their primary function is acquisition of nutrients and water, in particular phosphate. They are the site of transporters, exudation of active compounds and infection point of symbiotic microbial interactions. They have a profound effect on rhizosphere characteristics and are a potentially useful target for breeding crops for future agricultural sustainability.

scholarly journals Nontarget Tree Mortality after Tree-of-Heaven (Ailanthus altissima) Injection with Imazapyr

2008 ◽  
Vol 25 (2) ◽  
pp. 66-72 ◽  
Author(s):  
Kevin Lewis ◽  
Brian McCarthy
Keyword(s):  
Mycorrhizal Fungi ◽  
Tree Mortality ◽  
Root Exudation ◽  
Ailanthus Altissima ◽  
Tree Of Heaven ◽  
Increased Risk ◽  
Vegetation Heterogeneity ◽  
Nontarget Species ◽  
Root Grafts ◽  
Injection Risk

Abstract Tree-of-heaven (Ailanthus altissima Miller [Swingle]) can be managed easily with herbicide injection. However, the potential herbicide translocation to neighboring trees must be evaluated before widespread recommendations for herbicide injections. We assessed the nontargettranslocation of imazapyr (Arsenal), an herbicide commonly used to manage woody vegetation in forests, from injected tree-of-heaven to neighboring noninjected stems. Targeted imazapyr injections not only killed all injected tree-of-heaven, but also killed 17.5% of neighboring (within 3 m) noninjected tree-of-heaven and eight other tree species 62 weeks after treatment. Nontarget mortality from herbicide translocation decreased as the distance from injected tree-of-heaven increased (up to 3 m) and as stem diameter of noninjected plants increased. The plausible modes ofinter- and intraspecific herbicide translocation include root grafts, mutually shared mycorrhizal fungi, root exudation and absorption, and/or leaf senescence. Because tree-of-heaven is clonal, patch size and vegetation heterogeneity will be an important determinant of herbicide injectionprotocols. In forest environments with many small patches (i.e., high edge to interior ratio) or mixed species stands, nontarget hardwoods are at an increased risk of mortality. In isolated large patches (with lower edge to interior ratio) or dense monospecific clones, injection risk to nontarget species will be relatively low.

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