0000000000958510
AUTHOR
Nassima Ait Lahmidi
Sugar transport and partitioning during arbuscular mycorrhizal symbiosis (from basic to applied science)
The nutrient exchanges between plant and fungus are the key elements of the arbuscular mycorrhizal (AM) symbiosis. The fungus improves the plant uptake of mineral nutrients, mainly phosphate, while the plant provides the fungus with photosynthetically assimilated carbohydrates. Although knowledge about the mechanisms underlying nutrient exchanges between the symbiotic partners still remains very limited, recent advances in mycorrhiza research have allowed identification and functional characterization of fungal sugar transport systems. The present thesis firstly focused on the identification and characterization of sugar transporters from the model arbuscular mycorrhizal fungus (AMF) Rhizop…
Sugar exchanges in arbuscular mycorrhiza: RiMST5 and RiMST6, two novel Rhizophagus irregularis monosaccharide transporters, are involved in both sugar uptake from the soil and from the plant partner
SPE IPM INRA UB CT1; International audience; Arbuscular mycorrhizal (AM) fungi are associated with about 80% of land plants. AM fungi provide inorganic nutrients to plants and in return up to 20% of the plant-fixed CO2 is transferred to the fungal symbionts. Since AM fungi are obligate biotrophs, unraveling how sugars are provided to the fungus partner is a key for understanding the functioning of the symbiosis. In this study, we identified two new monosaccharide transporters from Rhizophagus irregularis (RiMST5 and RiMST6) that we characterized as functional high affinity monosaccharide transporters. RiMST6 was characterized as a glucose specific, high affinity H(+) co-transporter. We prov…
Identification of sugar transporters in arbuscular mycorrhiza, from basic to applied science
Our study focuses on sugar transporters from both plant and fungal partners at the symbiotic interface to better understand biotrophic exchange systems. Thereby, a collection of putative contigs and ESTs of hexose transporters from Medicago truncatula and Fragaria x ananassa will be processed. The full length sequences will be cloned for functional complementation and uptake experiments in transport deficient yeast mutants. This work also investigates the influence of different mycorrhizal fungi on (1) the expression level of sugar transporters and (2) the economically relevant part of F. x ananassa by analyzing its impact on the plant and the fruit. To this aim, combination of phenological…
Expression of Sorghum bicolor ammonium transporters upon colonization with arbuscular mycorrhizal fungi
Arbuscular mycorrhizal fungi (AMF) are important plant symbionts, trading mineral nutrients beyond the reach of roots, in particular ammonium, in exchange to their host’s photosynthetic products. Sorghum bicolor is one of the world's leading cereal crops, providing food, fibre and fuel across a range of environments and production systems. It has a particular ability to be productive even under strongly adverse conditions, tolerating much more severe drought than most other grain crops. As its genome has recently been sequenced, we have characterized all eight members of the ammonium transporter (AMT) family and studied their expression in different tissues of field-grown plants. While most…
Is co-inoculation of strawberry plants with plant growth-promoting bacteria and arbuscular mycorrhizal fungi leading to an improvement of growth and fruit quality?
Is co-inoculation with plant growth promoting bacteria and arbuscular mycorrhizal fungi increasing strawberry production yields ?
The competitiveness to form nodules shapes the capacities of Rhizobium leguminosarum sv viciae communities to promote symbiosis with specific hosts
National audience; Cultivated fabeae legumes (pea, fababean, lentil) develop root nodules resulting from the symbiotic interaction with Rhizobium leguminosarum sv. viciae (Rlv). Individual Rlv bacteria are able to associate with various potential hosts, but in soil they are in mixture and they display a wide range of competitiveness to form nodules (CFN). Because in Rlv, CFN and capacity to fix nitrogen are genetically independent, CFN limits the effectiveness of inoculation strategies as efficient bacteria are often outcompeted by poorly efficient Rlv bacteria of the soil community. We developed a strategy to identify bacterial genes controlling CFN. A worldwide collection of 240 Rlv isola…
Sugar exchanges in arbuscular mycorrhiza : Characterization and role of two new monosaccharide transporters from the model fungus Rhizophagus irregularis
Identification of sugar transporters in arbuscular mycorrhiza
Our study focuses on sugar transporters from both plant and fungal partners at the symbiotic interface to better understand biotrophic exchange systems. Thereby, a collection of putative contigs and ESTs of hexose transporters from Medicago truncatula and Fragaria x ananassa will be processed. The full length sequences will be cloned for functional complementation and uptake experiments in transport deficient yeast mutants. This work also investigates the influence of different mycorrhizal fungi on (1) the expression level of sugar transporters and (2) the economically relevant part of F. x ananassa by analyzing its impact on the plant and the fruit. To this aim, combination of phenological…