Project description:Two potato cultivars, Russet Burbank and Bionta, were inoculated with three different endophytes containing different AHL types. The impact of the endophytes to the different cultivars was measured by gene expression analysis with a customized microarray
Project description:Two potato cultivars, Russet Burbank and Bionta, were inoculated with three different endophytes containing different AHL types. The impact of the endophytes to the different cultivars was measured by gene expression analysis with a customized microarray B. phytofirmans type strain PsJN was originally isolated as a contaminant from surface-sterilized, Glomus vesculiferum-infected onion roots (Nowak et al., 1998), whereas strain P6 RG6-12 was isolated from the rhizosphere of a grassland in the Netherlands (Salles et al., 2006). This strain was selected based on its similarity to strain PsJN based on 16S rRNA gene homology, and similar phenotypic features. Both strains were generally cultivated on King's medium (King et al., 1954). For the mutant AHL to the strain B. phytofirmans PsJN a quorum quenching approach as described by Wopperer et al., 2006 was employed. Plasmid pMLBAD-aiiA, which contains aiiA, the Bacillus sp. 240B1 lactonase gene, was transferred to B. phytofirmans PsJN by triparental mating as described by de Lorenzo and Timmis (1994). 2 cultivars, 3 endophytes
Project description:Nitrogen is the most important mineral nutrient of plant. As a worldwide and economically important vegetable, cucumber (Cucumis sativus L.) has a strong nitrogen-dependence. We took whole transcriptome sequencing approach to compare the gene expression profiles of cucumber leaves and roots grown under sufficient or insufficient nitrate supply. Analysis of the transcriptome data revealed that the root and leaf adapt different response mechanisms to long-term nitrogen deficiency. Photosynthesis and carbohydrate biosynthetic process were pronouncedly and specifically reduced in leaf, while the ion transport function, cell wall and phosphorus-deficiency response function seem systematically down-regulated in root. Genes in nitrogen uptake and assimilation are decreased in root, but some are increased in leaf under nitrogen deficiency. Several lines of evidence suggest that the altered gene expression networks support the basic cucumber growth and development likely through successful nitrogen remobilization involving in the induced expression of genes in ABA and ethylene pathways.
Project description:Root-microbe interaction and its specialized root nodule structures and functions are well studied. In contrast, leaf nodules harboring microbial endophytes in special glandular leaf structures have only recently gained increased interest as plant-microbe phyllosphere interactions. Here, we applied a comprehensive metabolomics platform in combination with natural product isolation and characterization to dissect leaf and leaf nodule metabolism and functions in <i>Ardisia crenata</i> (Primulaceae) and <i>Psychotria punctata</i> (Rubiaceae). The results indicate that abiotic stress resilience plays an important part within the leaf nodule symbiosis of both species. Both species showed metabolic signatures of enhanced nitrogen assimilation/dissimilation pattern and increased polyamine levels in nodules compared to leaf lamina tissue potentially involved in senescence processes and photosynthesis. Multiple links to cytokinin and REDOX-active pathways were found. Our results further demonstrate that secondary metabolite production by endophytes is a key feature of this symbiotic system. Multiple anhydromuropeptides (AhMP) and their derivatives were identified as highly characteristic biomarkers for nodulation within both species. A novel epicatechin derivative was structurally elucidated with NMR and shown to be enriched within the leaf nodules of <i>A. crenata</i>. This enrichment within nodulated tissues was also observed for catechin and other flavonoids indicating that flavonoid metabolism may play an important role for leaf nodule symbiosis of <i>A. crenata.</i> In contrast, pavettamine was only detected in <i>P. punctata</i> and showed no nodule specific enrichment but a developmental effect. Further natural products were detected, including three putative unknown depsipeptide structures in <i>A. crenata</i> leaf nodules. The analysis presents a first metabolomics reference data set for the intimate interaction of microbes and plants in leaf nodules, reveals novel metabolic processes of plant-microbe interaction as well as the potential of natural product discovery in these systems.
Project description:Pea (Pisum. sativum L.) is a traditional and important edible legume that can be sorted into grain pea and vegetable pea according to their harvested maturely or not. Vegetable pea by eating the fresh seed is becoming more and more popular in recent years. These two type peas display huge variations of the taste and nutrition, but how seed development and nutrition accumulation of grain pea and vegetable pea and their differences at the molecular level remains poorly understood. To understand the genes and gene networks regulate seed development in grain pea and vegetable pea, high throughput RNA-Seq and bioinformatics analysis were used to compare the transcriptomes of vegetable pea and grain pea developing seed. RNA-Seq generated 18.7 G raw data, which was then de novo assembled into 77,273 unigenes with a mean length of 930 bp. Functional annotation of the unigenes was carried out using the nr, Swiss-Prot, COG, GO and KEGG databases. There were 459 and 801 genes showing differentially expressed between vegetable pea and grain pea at early and late seed maturation phases, respectively. Sugar and starch metabolism related genes were dramatically activated during pea seed development. The up-regulated of starch biosynthesis genes could explain the increment of starch content in grain pea then vegetable pea; while up-regulation of sugar metabolism related genes in vegetable pea then grain pea should participate in sugar accumulation and associated with the increase in sweetness of vegetable pea then grain pea. Furthermore, transcription factors were implicated in the seed development regulation in grain pea and vegetable pea. Thus, our results constitute a foundation in support of future efforts for understanding the underlying mechanism that control pea seed development and also serve as a valuable resource for improved pea breeding.