Project description:Root exudates are composed of primary and secondary metabolites known to modulate the rhizosphere microbiota. Glucosinolates are defense compounds present in the Brassicaceae family capable of deterring pathogens, herbivores and biotic stressors in the phyllosphere. In addition, traces of glucosinolates and their hydrolyzed byproducts have been found in the soil, suggesting that these secondary metabolites could play a role in the modulation and establishment of the rhizosphere microbial community associated with this family. We used Arabidopsis thaliana mutant lines with disruptions in the indole glucosinolate pathway, liquid chromatography-tandem mass spectrometry (LC-MS/MS) and 16S rRNA amplicon sequencing to evaluate how disrupting this pathway affects the root exudate profile of Arabidopsis thaliana, and in turn, impacts the rhizosphere microbial community. Chemical analysis of the root exudates from the wild type Columbia (Col-0), a mutant plant line overexpressing the MYB transcription factor ATR1 (atr1D) which increases glucosinolate production, and the loss-of-function cyp79B2cyp79B3 double mutant line with low levels of glucosinolates confirmed that alterations to the indole glucosinolate biosynthetic pathway shifts the root exudate profile of the plant. We observed changes in the relative abundance of exuded metabolites. Moreover, 16S rRNA amplicon sequencing results provided evidence that the rhizobacterial communities associated with the plant lines used were directly impacted in diversity and community composition. This work provides further information on the involvement of secondary metabolites and their role in modulating the rhizobacterial community. Root metabolites dictate the presence of different bacterial species, including plant growth-promoting rhizobacteria. Our results suggest that alterations in the indole glucosinolate pathway cause disruptions beyond the endogenous levels of the plant, significantly changing the abundance and presence of different metabolites in the root exudates of the plants as well as the microbial rhizosphere community.
Project description:We aimed to identify miRNA regulated by alternate bearing in O. europaea. For this purpose, six olive (Olea europaea L. )(Ayvalık variety) small RNA libraries were constructed from fruits (ripe and unripe) and leaves ("on-year" and "off-year" mature -leaven in November and juvenile - leaven in July plants) and sequenced by high-throughput Illumina sequencing. Bioinformatics analyses of 93,526,915 reads identified 135 conserved miRNA, belonging to 22 miRNA families in olive tree. In addition, 38 novel miRNA were discovered in the datasets. Expression of olive tree miRNA varied greatly among the six libraries, indicating contribution of diverse miRNA in balancing between reproductive and vegetative phases. The differential expression of miRNA was evaluated on the basis of the developmental phase of the samples.
2012-12-18 | GSE42978 | GEO
Project description:Fungal endophytes of olive tree
Project description:We aimed to identify miRNA regulated by alternate bearing in O. europaea. For this purpose, six olive (Olea europaea L. )(Ayvalık variety) small RNA libraries were constructed from fruits (ripe and unripe) and leaves ("on-year" and "off-year" mature -leaven in November and juvenile - leaven in July plants) and sequenced by high-throughput Illumina sequencing. Bioinformatics analyses of 93,526,915 reads identified 135 conserved miRNA, belonging to 22 miRNA families in olive tree. In addition, 38 novel miRNA were discovered in the datasets. Expression of olive tree miRNA varied greatly among the six libraries, indicating contribution of diverse miRNA in balancing between reproductive and vegetative phases. The differential expression of miRNA was evaluated on the basis of the developmental phase of the samples. Sequences of six olive miRNAs (Olea europaea L. )(Ayvalık variety) plants (ripe and unripe fruits, leaves of mature and juvenile plants of both "on-year" and "off-year") were generated by Illumina sequencing
Project description:A comparative transcriptomics approach was used as a tool to unravel gene regulatory networks underlying salinity response in olive trees by simulating as much as possible olive growing conditions in the field. Specifically, we investigated the genotype-dependent differences in the transcriptome response of two olive cultivars, a salt tolerant and a salt sensitive. A 135 day long comparative salinity experiment was conducted using one year old trees exposed to NaCl stress for 90 days followed by 45 days of post-stress period. Total RNA was extracted from the root samples after 15, 45 and 90 days of NaCl-treated and un-treated olive trees as well as after 15 and 45 days of post-treatment period and used for microarray hybridizations using a loop design. Hierarchical clustering of differentially expressed transcripts revealed two major, distinct clusters for each cultivar. Despite the limited number of probe set, transcriptional regulatory networks were constructed for the salt-tolerant and salt-sensitive cultivar. The comparison of the salt responsive transcriptional regulatory networks in olive with those reported for Arabidopsis suggests that a tree species might respond in a similar to Arabidopsis way at the transcriptome level under salinity stress.