Biology subjects

Gasciolli, V.

Publications and source records attributed to Gasciolli, V..

3 recordsLinked to original sources

bioRxiv2025

Soil phosphate availability modulates the arbuscular mycorrhizal fungal community and mycorrhizal nutrition in wheat

O_LIUnderstanding the contributions of arbuscular mycorrhizal fungi (AMF) to plant nutrition is essential for sustainable agriculture. We hypothesised that soil phosphorus (P) availability modulates the diversity and functionality of wheat root-associated AMF community, particularly the mycorrhizal nutrition. C_LIO_LIWheat plants were sampled over two campaigns (2019 and 2022) in a long-term P fertilisation trial. The expression of the wheat transporters involved in the mycorrhizal nutrition was assessed by RT-qPCR, and AMF community composition by metabarcoding. Complementary experiments under controlled conditions were performed to further study the interaction between nitrogen (N) and P availability on AM. C_LIO_LIDifferent effects of P on AMF colonisation and transporter expression were observed in field-grown wheat depending on the campaigns, which differed in wheat N status. Controlled experiments confirmed that AMF colonisation depends on the limitation of either P or N, but that regulation of peri-arbuscular phosphate, ammonium and nitrate transporters depends on the nature of the limiting soil nutrients. Additionally, AMF communities varied according to the soil P availability, with the Funneliformis genus becoming more dominant under high P conditions for both years. C_LIO_LITogether, our findings show that N and P availability jointly shape root AMF communities and AM functioning. Combining community profiling and molecular markers of colonisation and nutrition offers a framework to better understand AMF contributions to plant nutrition across agroecosystems. C_LI

plant biology↗

bioRxiv2024

A new group of LysM-RLKs involved in symbiotic signal perception and arbuscular mycorrhiza establishment

Lipo-chitooligosaccharides (LCO) and short-chain chitooligosaccharides (CO) are produced by arbuscular mycorrhizal fungi (AMF) and activate the plant symbiosis signalling pathway, which is essential for mycorrhiza formation. High affinity LCO receptors belonging to the LysM receptor-like kinase (LysM-RLK) phylogenetic group LYR-IA play a role in AM establishment, but no plant high affinity short-chain CO receptors have yet been identified. Here we studied members of the uncharacterized LYR-IB group, and found that they show high affinity for LCO, short- and long-chain CO, and play a complementary role with the LYR-IA LCO receptors for AM establishment. While LYR-IB knock out mutants had a reduced AMF colonization in several species, constitutive/ectopic expression in wheat increased AMF colonization. LYR-IB function is conserved in all tested angiosperms, but in most japonica rice a deletion creates a frameshift in the gene, explaining differences in AM phenotypes between rice and other monocot single LYR-IA mutants. In conclusion, we identified a class of LysM-RLK receptors in angiosperms with new biochemical properties and a role in both LCO and CO perception for AM establishment.

plant biology↗

bioRxiv2020

Rhizobium leguminosarum symbiovar viciae strains are natural wheat endophytes and can stimulate root development and colonization by arbuscular mycorrhizal fungi

O_LIAlthough rhizobia establishing a nitrogen-fixing symbiosis with legumes are also known to promote growth in non-legumes, studies on rhizobia association with wheat roots are scarce. C_LIO_LIWe searched for Rhizobium leguminosarum symbiovar viciae (Rlv) strains naturally competent for wheat roots colonization. We isolated 20 strains and tested the ability of a subset for wheat roots colonization when co-inoculated with other Rlv. We also measured the effect of these strains on wheat root architecture and Arbuscular Mycorrhizal Fungal (AMF) colonization. C_LIO_LIWe found a low diversity of Rlv in wheat roots compared to that observed in the Rlv species complex. Only a few strains, including those isolated from wheat roots, and one strain isolated from pea nodules, were efficient to colonize wheat roots in co-inoculation conditions. These strains had a high ability for endophytic colonization of wheat root and were able to stimulate root development and AMF colonization in single strain inoculation conditions. C_LIO_LIThese results suggest that wheat is an alternative host for some Rlv; nevertheless, there is a strong competition between Rlv strains for wheat root colonization. Furthermore, our study suggests that the level of endophytic colonization is critical for Rlv ability to promote wheat growth. C_LI

microbiology↗