Project description:Internal aeration is crucial for root growth in waterlogged soil. A barrier to radial oxygen loss (ROL) can enhance long- distance oxygen transport via the aerenchyma to the root tip; a higher oxygen concentration at the apex enables root growth into anoxic soil. The ROL barrier is formed within the outer part of roots (OPR). Suberin and/or lignin depos- ited in cell walls are thought to contribute to the barrier, but it is unclear which compound is the main constituent. This study describes gene expression profiles during ROL barrier formation in rice roots to determine the relative responses of suberin and/or lignin biosyntheses for the barrier. OPR tissues were isolated by laser microdissection and their transcripts were analysed by microarray. A total of 128 genes were significantly up- or downregulated in the OPR during the barrier formation. Genes associated with suberin biosynthesis were strongly upregulated, whereas genes associated with lignin biosynthesis were not. By an ab initio analysis of the promoters of the upregulated genes, the putative cis-elements that could be associated with transcription factors, WRKY, AP2/ERF, NAC, bZIP, MYB, CBT/DREB, and MADS, were elucidated. They were particularly associated with the expression of transcrip- tion factor genes containing WRKY, AP2, and MYB domains. A semiquantitative reverse-transcription PCR analysis of genes associated with suberin biosynthesis (WRKY, CYP, and GPAT) confirmed that they were highly expressed during ROL barrier formation. Overall, these results suggest that suberin is a major constituent of the ROL barrier in roots of rice. 23-d-old plants were either continued in aerated solution or transplanted into N2-flushed or stagnant deoxygenated solution for 9 h. After treating the roots of plants in aerated, stagnant, or N2-flushed conditions for 9h, the basal parts (12.5 -22.5mm below the root - shoot junction) of the adventitious roots were collected. Cells in OPR (including exodermis and sclerenchyma) were isolated using laser microdissection. RNA extracted from the isolated OPR was analysed with a 44k rice oligo-DNA microarray. Total RNAs were labeled with a Quick Amp Labeling Kit (Agilent Technologies) according to the manufacturerM-bM-^@M-^Ys instructions. Aliquots of Cy5-labeled and Cy3-labeled cRNA (10 ng each) were used for hybridization in a rice 44K oligo-DNA microarray.
Project description:Internal aeration is crucial for root growth in waterlogged soil. A barrier to radial oxygen loss (ROL) can enhance long- distance oxygen transport via the aerenchyma to the root tip; a higher oxygen concentration at the apex enables root growth into anoxic soil. The ROL barrier is formed within the outer part of roots (OPR). Suberin and/or lignin depos- ited in cell walls are thought to contribute to the barrier, but it is unclear which compound is the main constituent. This study describes gene expression profiles during ROL barrier formation in rice roots to determine the relative responses of suberin and/or lignin biosyntheses for the barrier. OPR tissues were isolated by laser microdissection and their transcripts were analysed by microarray. A total of 128 genes were significantly up- or downregulated in the OPR during the barrier formation. Genes associated with suberin biosynthesis were strongly upregulated, whereas genes associated with lignin biosynthesis were not. By an ab initio analysis of the promoters of the upregulated genes, the putative cis-elements that could be associated with transcription factors, WRKY, AP2/ERF, NAC, bZIP, MYB, CBT/DREB, and MADS, were elucidated. They were particularly associated with the expression of transcrip- tion factor genes containing WRKY, AP2, and MYB domains. A semiquantitative reverse-transcription PCR analysis of genes associated with suberin biosynthesis (WRKY, CYP, and GPAT) confirmed that they were highly expressed during ROL barrier formation. Overall, these results suggest that suberin is a major constituent of the ROL barrier in roots of rice.
Project description:ABSTRACT: Background: Though central to our understanding of how roots perform their vital function of scavenging water and solutes from the soil, no direct genetic evidence currently exists to support the foundational model that suberin acts to form a chemical barrier limiting the extracellular, or apoplastic, transport of water and solutes in plant roots. Methodologies/Principle Findings: Using the newly characterized enhanced suberin1 (esb1) mutant, we established a connection in Arabidopsis thaliana between suberin in the root, and both water movement through the plant, and solute accumulation in the shoot. Esb1 mutants, characterized by increased root suberin, were found to have reduced day time transpiration rates, and increased water use efficiency during their vegetative growth period. Furthermore, these changes in suberin and water transport were associated with decreases in the accumulation of Ca, Mn and Zn, and increases in the accumulation of Na, S, K, As, Se and Mo in the shoot. Conclusions/Significance: Here we present direct genetic evidence establishing that suberin in the roots plays a critical role in controlling both water and mineral ion uptake and transport to the leaves. The changes observed in the elemental accumulation in leaves are also interpreted as evidence that a significant component of the radial root transport of Ca, Mn and Zn occurs in the apoplast. Keywords: genomic hybridization bulked segregant analysis
Project description:The study aims essentially at the characterisation of suberin degradation mechanisms by Aspergillus nidulans, at a fundamental level. Suberin is an important protective barrier in plant, thus the study of its biodegradation significantly impacts on phytopatology. In addition, fungal suberin degrading enzymes might provide important insights to develop new waste management, bioremediation and biodeterioration prevention strategies.
Project description:⢠A comparison of the transcriptomes of russeted vs. waxy apple exocarps previously highlighted a tight relationship between a gene encoding a MYB-type transcription factor, MdMYB93, and some key suberin biosynthetic genes. The present work assesses the role of this transcription factor in the suberization process. ⢠A phylogenetic analysis of MdMYB93 and Arabidopsis thaliana MYBs was performed and the function of MdMYB93 was further investigated using Agrobacterium-mediated transient overexpression in Nicotiana benthamiana leaves. An RNA-Seq analysis was performed to highlight the MdMYB93-regulated genes. UPLC-TripleTOF and GC-MS were used to investigate alterations in phenylpropanoid, soluble free lipid, and lipid polyester contents. ⢠A massive accumulation of suberin and its biosynthetic precursors in MdMYB93 agro-infiltrated leaves was accompanied by a remobilization of phenylpropanoids and an increased amount of lignin precursors. Gene expression profiling displayed a concomitant alteration of lipid and phenylpropanoid metabolism, cell wall development, and extracellular transport, with a large number of induced transcripts predicted to be involved in suberin deposition. ⢠The present work supports a major role of MdMYB93 in the regulation of suberin deposition in russeted apple skins, from the synthesis of monomeric precursors, their transport, polymerization, and final deposition as suberin in primary cell wall. In order to draw a consistent picture of a gene expression profile of the MYB93 induced was performed comparing of 4 biological replicates of Nicotiana benthamiana leaves infiltrated with Pearleygate103 35S::MdMYB93 and 4 biological replicates of control plants infiltrated with P19 only.
Project description:Potential components of the barrier to radial oxygen loss (ROL) are suberin and/or lignin, which accumulate at the cell wall in the cells of peripheral cell layers of the root. Chemical composition of the apoplastic barrier in rice roots was characterized and it was suggested that ROL can be restricted by the formation of a suberized exodermis and/or lignified sclerenchyma in the outer part of the root. To characterize reorganization of primary carbon metabolism in rice roots during the ROL barrier formation, we obtained the profiles of polar metabolites and the profiles of fatty acids of different zones of rice roots from plants growing in stagnant (anaerobic) and in well aerated medium. Biochemical data are combined with the results of microarray analysis.
Project description:• A comparison of the transcriptomes of russeted vs. waxy apple exocarps previously highlighted a tight relationship between a gene encoding a MYB-type transcription factor, MdMYB93, and some key suberin biosynthetic genes. The present work assesses the role of this transcription factor in the suberization process. • A phylogenetic analysis of MdMYB93 and Arabidopsis thaliana MYBs was performed and the function of MdMYB93 was further investigated using Agrobacterium-mediated transient overexpression in Nicotiana benthamiana leaves. An RNA-Seq analysis was performed to highlight the MdMYB93-regulated genes. UPLC-TripleTOF and GC-MS were used to investigate alterations in phenylpropanoid, soluble free lipid, and lipid polyester contents. • A massive accumulation of suberin and its biosynthetic precursors in MdMYB93 agro-infiltrated leaves was accompanied by a remobilization of phenylpropanoids and an increased amount of lignin precursors. Gene expression profiling displayed a concomitant alteration of lipid and phenylpropanoid metabolism, cell wall development, and extracellular transport, with a large number of induced transcripts predicted to be involved in suberin deposition. • The present work supports a major role of MdMYB93 in the regulation of suberin deposition in russeted apple skins, from the synthesis of monomeric precursors, their transport, polymerization, and final deposition as suberin in primary cell wall.
Project description:Down-regulation of reactive oxygen species build-up in chloroplasts by expression of a plastid-targeted flavodoxin protects potato leaves under drought conditions. To better understand these effects we compared the transcriptomic alterations in a pre-symtomatic stage of drought treatment on leaves of Fld-expressing potato plants and their wild-type siblings.
Project description:Light is a major environmental factor that affects metabolic pathways and stimulates the production of secondary metabolites in potato. However, adaptive changes in potato metabolic pathways and physiological functions triggered by light are partly explained by gene expression changes. Regulation of secondary metabolic pathways in potato has been extensively studied at transcriptional level, but little is known about the mechanisms of post-transcriptional regulation by miRNAs. To identify light-responsive miRNAs/mRNAs and construct putative metabolism pathways regulated by the miRNA-mRNA pairs, an integrated omics (sRNAome and transcriptome) analysis was performed to potato under light stimulus. A total of 31 and 48 miRNAs were identified to be differentially expressed in the leaves and tubers, respectively. Among the DEGs, 1353 genes in the leaves and 1841 genes in the tubers were upregulated, while 1595 genes in the leaves and 897 genes in the tubers were downregulated by light. Mapman enrichment analyses showed that genes related to MVA pathway, alkaloids-like, phenlypropanoids, flavonoids, and carotenoids metabolism were significantly upregulated, while genes associated with major CHO metabolism were repressed in the leaves and tubers. Integrated miRNA and mRNA profiles revealed that light-responsive miRNAs are important regulators in alkaloids metabolism, UMP-salvage, lipid biosynthesis, and cellulose catabolism. Moreover, several miRNAs may participate in glycoalkaloids metabolism via JA signaling pathway, UDP-glucose biosynthesis and hydroxylation reaction. This study provides a global view of transcriptome response in potato response to light, our results suggest that miRNAs might play important roles in secondary metabolic pathways, especially in glycoalkaloid biosynthesis. The findings will enlighten us on the genetic regulation of secondary metabolite pathways and pave the way for future application of genetically engineered potato.
Project description:In the present study molecular interactions between potato plants, Colorado potato beetle (CPB) larvae and Potato virus YNTN (PVYNTN) were investigated by analyzing gene expression in potato leaves. Grant ID: J4-4165 Slovenian Research Agency ARRS Growth and defense trade-offs in multitrophic interaction between potato and its two major pests Grant ID: P4-0165 Slovenian Research Agency ARRS Biotechnology and Plant Systems Biology