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Plant growth response to Arbuscular Mycorrhizal (AM) fungi is variable and depends on genetic and environment factors that still remain largely unknown. Identification of these factors can be envisaged using high-throughput and accurate plant phenotyping.We setup experimental conditions based on a two-compartment system allowing to measureBrachypodium distachyonmycorhizal growth response (MGR) in an automated phenotyping greenhouse. We developed a new image analysis software“IPSO Phen”to estimate ofB. distachyonaboveground biomass.We found a positive MGR in theB. distachyonBd3-1 genotype inoculated with the AM fungiRhizophagus irregularisonly if nitrogen and phosphorus were added together in the compartment restricted to AM fungi. Using this condition, we found genetic diversity inB. distachyonfor MGR ranging from positive to negative MGR depending on the plant genotype tested.Our result on the interaction between nitrogen and phosphorus for MGR inB. distachyonopens new perspectives about AM functioning. In addition, our open-source software allowing to test and run image analysis parameters on large amount of images generated by automated plant phenotyping facilities, will help to screen large panels of genotypes and environmental conditions to identify the factors controlling the MGR.

International audience; Auxin is a major phytohormone that controls root development. A role for auxin is also emerging in the control of plant-microbe interactions, including for the establishment of root endosymbiosis between plants and arbuscular mycorrhizal fungi (AMF). Auxin perception is important both for root colonization by AMF and for arbuscule formation. AMF produce symbiotic signals called lipo-chitooligosaccharides (LCOs) that can modify auxin homeostasis and promote lateral root formation (LRF). Since Brachypodium distachyon (Brachypodium) has a different auxin sensitivity compared to other plant species, we wondered whether this would interfere with the effect of auxin in arbuscular mycorrhizal (AM) symbiosis. Here we tested whether tar2l(hypo) a Brachypodium mutant with an increase in endogenous auxin content is affected in LRF stimulation by LCOs and in AM symbiosis. We found that, in contrast to control plants, LCO treatment inhibited LRF of the tar2l(hypo) mutant. However, the level of AMF colonization and the abundance of arbuscules were increased in tar2l(hypo) compared to control plants, suggesting that auxin also plays a positive role in both AMF colonization and arbuscule formation in Brachypodium.

International audience

The advent of genomic based precision medicine led to the implementation of biomarker testing in metastatic non-small cell lung cancer (NSCLC) patients. Next generation sequencing (NGS) has been recently implemented to routine diagnostic requirements in lung oncology. Areas covered: Two cases of patients with metastatic NSCLC for whom NGS analysis performed on both tumor and liquid biopsy has not improved the clinical course of their disease are reported. These cases illustrate the difficulty of the so-called 'personalized or precision' medicine in clinical routine practice for metastatic NSCLC. Expert commentary: Discovery and detection of critical cancer-gene alterations better indicates targeted therapies that must be administered to improve the care of NSCLC patients in the personalized medicine era. There has been much interest in the literature and the scientific community for NGS tailored therapies approach for patients. However, there may be a gap between this theoretical stratified medicine and clinical practice. The advantages and drawbacks of NGS on tumor tissue and cell-free DNA for metastatic NSCLC are discussed.

Summary Bacterial lipo-chitooligosaccharides (LCOs) are key mediators of the nitrogen-fixing root nodule symbiosis (RNS) in legumes. The isolation of LCOs from arbuscular mycorrhizal fungi suggested that LCOs are also signaling molecules in arbuscular mycorrhiza (AM). However, the corresponding plant receptors have remained uncharacterized. Here we show that petunia and tomato mutants in the LysM receptor-like kinases LYK10 are impaired in AM formation. Petunia and tomato LYK10 proteins have a high affinity for LCOs (Kd in the nM range) comparable to that previously reported for a legume LCO receptor essential for the RNS. Interestingly, the tomato and petunia LYK10 promoters, when introduced into a legume, were active in nodules similarly to the promoter of the legume orthologous gene. Moreover, tomato and petunia LYK10 coding sequences restored nodulation in legumes mutated in their orthologs. This combination of genetic and biochemical data clearly pinpoints Solanaceous LYK10 as part of an ancestral LCO perception system involved in AM establishment, which has been directly recruited during evolution of the RNS in legumes., Highlights • Mutants in Solanaceaous LysM receptors LYK10 are impaired in arbuscular mycorrhiza • LYK10 proteins have a high affinity for lipo-chitooligosaccharidic signal molecules • LYK10 promoter is expressed in arbuscule-containing cells in tomato roots • Solanaceaous LYK10 can restore nodulation in legumes mutated in their orthologs, Soil rhizobial bacteria and arbuscular mycorrhizal (AM) fungi produce lipo-chitooligosaccharidic (LCO) signal molecules. Girardin et al. show that plant LCO receptors are involved in establishment of the ancient AM symbiosis and have been recruited during evolution for establishment of the nitrogen-fixing root nodule symbiosis with rhizobia.

Background: With the integration of various targeted therapies into the clinical management of patients with advanced lung adenocarcinoma, next-generation sequencing (NGS) has become the technology of choice and has led to an increase in simultaneously interrogated genes. However, the broader adoption of NGS for routine clinical practice is still hampered by sophisticated workflows, complex bioinformatics analysis and medical interpretation. Therefore, the performance of the novel QIAGEN GeneReader NGS system was compared to an in-house ISO-15189 certified Ion PGM NGS platform. Methods: Clinical samples from 90 patients (60 Retrospectively and 30 Prospectively) with lung adenocarcinoma were sequenced with both systems. Mutations were analyzed and EGFR, KRAS, BRAF, NRAS, ALK, PIK3CA and ERBB2 genes were compared and sampling time and suitability for clinical testing were assessed. Results: Both sequencing systems showed perfect concordance for the overlapping genes. Correlation of allele frequency was r2 = 0.93 for the retrospective patients and r2 = 0.81 for the prospective patients. Hands-on time and total run time were shorter using the PGM system, while the GeneReader platform provided good traceability and up-to-date interpretation of the results. Conclusion: We demonstrated the suitability of the GeneReader NGS system in routine practice in a clinical pathology laboratory setting.