Project description:An RNA-Seq Transcriptome Analysis of Orthophosphate-Deficient White Lupin Reveals Novel Insights into Phosphorus Acclimation in Plants
Project description:Phosphorus, in its orthophosphate form (Pi), is one of the most limiting macronutrients in soils for plant growth and development. However, the whole genome molecular mechanisms contributing to plant acclimation to Pi deficiency remain largely unknown. White lupin (Lupinus albus L.) has evolved unique adaptations for growth in Pi deficient soils including the development of cluster roots to increase root surface area. In this study, we utilized RNA-Seq technology to assess global gene expression in white lupin cluster roots, normal roots, and leaves in response to Pi supply. We de novo assembled 277,224,180 Illumina reads from 12 cDNA libraries to build the first white lupin gene index (LAGI 1.0). This index contains 125,821 unique sequences with an average length of 1,155 bp. Of these sequences 50,734 were transcriptionally active (RPKM = 3) representing approximately 7.8% of the Lupinus albus genome, using the predicted genome size of Lupinus angustifolius as a reference. We identified a total of 2,128 sequences differentially expressed in response to Pi deficiency with a = 2-fold change and a p-value = 0.05. Twelve sequences were consistently differentially expressed due to Pi deficiency stress in three species, making them ideal candidates to monitor the Pi status of plants. Additionally, classic physiological experiments were coupled with RNA-Seq data to examine the role of cytokinin and gibberellic acid in Pi deficiency-induced cluster root development. This global gene expression analysis provides new insights into the biochemical and molecular mechanisms involved in the acclimation to Pi deficiency. Examination of 2 different tissue types (roots and leaves) under phosphorus (P) -sufficient or P-deficient condition with 3 biological replications per condition in white lupin (Lupinus albus).
Project description:Phosphorus, in its orthophosphate form (P(i)), is one of the most limiting macronutrients in soils for plant growth and development. However, the whole-genome molecular mechanisms contributing to plant acclimation to P(i) deficiency remain largely unknown. White lupin (Lupinus albus) has evolved unique adaptations for growth in P(i)-deficient soils, including the development of cluster roots to increase root surface area. In this study, we utilized RNA-Seq technology to assess global gene expression in white lupin cluster roots, normal roots, and leaves in response to P(i) supply. We de novo assembled 277,224,180 Illumina reads from 12 complementary DNA libraries to build what is to our knowledge the first white lupin gene index (LAGI 1.0). This index contains 125,821 unique sequences with an average length of 1,155 bp. Of these sequences, 50,734 were transcriptionally active (reads per kilobase per million reads ≥ 3), representing approximately 7.8% of the white lupin genome, using the predicted genome size of Lupinus angustifolius as a reference. We identified a total of 2,128 sequences differentially expressed in response to P(i) deficiency with a 2-fold or greater change and P ≤ 0.05. Twelve sequences were consistently differentially expressed due to P(i) deficiency stress in three species, Arabidopsis (Arabidopsis thaliana), potato (Solanum tuberosum), and white lupin, making them ideal candidates to monitor the P(i) status of plants. Additionally, classic physiological experiments were coupled with RNA-Seq data to examine the role of cytokinin and gibberellic acid in P(i) deficiency-induced cluster root development. This global gene expression analysis provides new insights into the biochemical and molecular mechanisms involved in the acclimation to P(i) deficiency.
Project description:Iron (Fe) and phosphorus (P) are essential nutrients for plants growth. Despite their abundance in soils, they are barely available for plants. In order to overcome these nutritional stresses, plants have evolved strategies including physiological, biochemical and morphological adaptations. Biosynthesis and release of low molecular weight compounds from the roots play a crucial role in P and Fe mobilization. White lupin (Lupinus albus L.) is considered a model plant for studying root exudates and for P-deficient adaptation. White lupin is able to markedly modify its root architecture by forming special structures called cluster roots, and modifies the rhizospheric soil characteristics by biosynthesising and releasing great amounts of exudates. These phenomena are quite well described in response to P deficiency, but there is few information on the adaptation of a cluster-root producing plant species to Fe deficiency. This prompted this work, aimed to characterize the physiological and transcriptomic responses of white lupin plants to Fe deficiency. Occurrence of Strategy I components and interactions with P nutrition has been also investigated in this work. Results showed a physiological and transcriptional link between the responses to Fe and P deficiency in white lupin roots. Phosphorus-deficient plants activated the Strategy I Fe acquisition mechanisms that lead to an enhanced Fe mobilization and translocation and that might help the P acquisition process. On the other hand, also the Fe deficiency enhanced the phosphate acquisition and some P-deficient-responsive genes were overexpressed.
Project description:Constituents of lupin seeds, like γ-conglutin and lupanine, have gained attention as potential complementary treatments for the management of dysglycaemia. Notwithstanding, the effect of other lupin components on carbohydrate metabolism, including β-conglutin protein, has received little attention. Here, we investigated the influence of the acute and chronic administration of β-conglutin on glycaemia modulation in normal and streptozotocin induced-to-diabetes rats. To identify potential molecular targets and pathways involved in this biological response, we analysed the liver transcriptome modulation exerted by β-conglutin in diabetes-induced rats using DNA microarrays. The acute administration of β-conglutin reduced the incremental area under the curve of glycaemia in normal and diabetes-induced animals. In a seven-day study with diabetic animals, glycaemia increased significantly in non-treated animals but remained unchanged in animals treated with a daily dose of β-conglutin. Noteworthy, total cholesterol was significantly lower at the end of the experimental period (−21.8%, p = 0.039). Results of the microarray test and gene ontology analyses revealed several targets and pathways modulated after β-conglutin treatment, including a down-regulation of Jun kinase activity. Moreover, our data indicate that targets related to oxidative stress, inflammation, and estrogenic activity might orchestrate these metabolic effects. In conclusion, our findings show that β-conglutin may be useful to manage postprandial glycaemia and reduce cholesterol levels under the dysglycaemia stage. We identified and proposed new potential molecular targets for further research related to the mechanism of action of β-conglutin.
Project description:RNA-seq analysis was performed on different developmental stages of cluster roots (pre-emergent, juvenile and mature) from Lupinus albus grown for 20 days under phosphorus-deficiency