Project description:Plants are naturally associated with diverse microbial communities, which play significant roles in plant performance, such as growth promotion or fending off pathogens. The roots of Alkanna tinctoria L. are rich in naphthoquinones, particularly the medicinally used chiral compounds alkannin, shikonin and their derivatives. Former studies already have shown that microorganisms may modulate plant metabolism. To further investigate the potential interaction between A. tinctoria and associated microorganisms we performed a greenhouse experiment, in which A. tinctoria plants were grown in the presence of three distinct soil microbiomes. At four defined plant developmental stages we made an in-depth assessment of bacterial and fungal root-associated microbiomes as well as all primary and secondary metabolites. Our results showed that the plant developmental stage was the most important driver influencing the plant metabolite content, revealing peak contents of alkannin/shikonin at the fruiting stage. In contrast, the soil microbiome had the biggest impact on the plant root microbiome. Correlation analyses performed on the measured metabolite content and the abundance of individual bacterial and fungal taxa suggested a dynamic, at times positive or negative relationship between root-associated microorganisms and root metabolism. In particular, the bacterial Allorhizobium-Neorhizobium-Pararhizobium-Rhizobium group and the fungal species Penicillium jensenii were found to be positively correlated with higher content of alkannins.
Project description:Cultivated carrot (Daucus carota L. ssp. sativus) was domesticated from wild carrot (Daucus carota L. ssp. carota) with radical different traits. The aim of this study was to compare the root transcriptomes between cultivated and wild carrots for SNP discovery, inferring domestication process, and identifying domestication genes. Six cultivated carrots representing main European carrot root types and five wild carrot populations from widely dispersed sites were used. The root transcriptomes were sequenced with multiplexing paried-end sequencing in Illumina Genome Analyzer IIx.
Project description:A comparative RNA-Seq analysis was done in root and shoot of Najran wheat cultivar between plants grown under two conditions: control (0 mM NaCl) and salt treatment (200 mM NaCl). The current study revealed differentially expressed genes and various associated biological pathways involved in plant responses to salt stress between the two conditions in the root and shoot plant tissues, providing important insights into the molecular mechanisms underlying salt tolerance in wheat.
Project description:Two diazotrophic bacteria, BPMP-PU-28 and BPMP-EL-40, isolated from the rhizosphere of a wild wheat ancestor (T. t. dicoccoides) grown in soil from its refuge area in the Fertile Crescent or from south of France, respectively, were shown to behave as efficient Plant Growth Promoting Rhizobacteria (PGPR) upon interaction with an elite wheat cultivar (Anvergur), providing about 50% of the seed nitrogen content in plants grown under low assimilable nitrogen availability. A bacterial growth medium was developed to investigate the effects of bacterial exudates on root development in the elite cultivar and to analyze the exo-metabolomes and exo-proteomes of the two strains. Altered root development was observed, with distinctive responses according to the strain, BPMP-PU-28 also inducing a strong increase in root hair length and density. Exo-metabolome analysis revealed a complex set of secondary metabolites including fatty acids potentially involved in volatile organic compounds (VOCs) metabolism, cyclopeptides that could act as phytohomone mimetics, quorum sensing molecules having inter-kingdom signaling properties and nutrient ion chelators. The exo-proteome comprised a set of strain specific enzymatic activities (e.g., proteases) and structural proteins belonging to outer-membrane vesicles likely to sequester metabolites, peptides and enzymes in their lumen. Thus, the wheat ability to establish efficient beneficial interactions with PGPR has not been profoundly reprogrammed during domestication and breeding, and PGPR constitutively exude rich and complex metabolomes and proteomes, in absence of partner roots, which could allow numerous mechanisms to simultaneously contribute to plant growth promotion and thereby broaden the range of responsive plant species.
