Project description:The root system is a crucial determinant of plant growth potential because of its important functions, e.g., acquisition of water and nutrients, structural support, and interaction with symbiotic organisms. Elucidating the molecular mechanisms of root development and functions is therefore necessary for improving plant productivity, particularly for crop plants including rice. As an initial step towards developing a comprehensive understanding of the root system, we performed a large-scale transcriptome analysis of the rice root via a combined laser microdissection and microarray analysis approach. We performed comprehensive microarray analysis of a rice crown root using laser microdissection and collected a total of 13 samples (3 replicates for each sample except for one sample, 38 total microarray data) representing 8 different developmental stages along the longitudinal axis and 3 distinct tissue-types along the radial axis at 2 different developmental stages. The 8 developmental stages represent root cap, division zone, elongation zone and maturation zone_I, II, III, IV and V. The 3 tissue-types represent epidermis/exodermis/sclerenchyma, cortex, and endodermis/pericycle/stele. In the maturation zone_V, the cortex consisted largely of aerenchyma (non-living cells) and was not used for the microarray analysis.
Project description:Broad-host root endophytes establish long-term interactions with a large variety of plants, thereby playing a significant role in natural and managed ecosystems and in evolution of land plants. To exploit plants as living substrates and to establish a compatible interaction with morphologically and biochemically extremely different hosts, endophytes must respond and adapt to different plant signals and host metabolic states. Here we identified host-adapted colonization strategies and host-specific effector candidates of the mutualistic root endophyte Piriformospora indica by a global investigation of fungal transcriptional responses to barley and Arabidopsis at different symbiotic stages. Additionally we examined the role played by nitrogen in these two diverse associations. Cytological studies and colonization analyses of a barley mutant and fungal RNAi strains show that distinct physiological and metabolic signals regulate host-specific lifestyle in P. indica. This is the foundation for exploring how distinct fungal and host symbiosis determinants modulate biotrophy in one host and saprotrophy in another host and, ultimately, gives hints into the mechanisms underlying host adaptation in root symbioses.
Project description:Broad-host root endophytes establish long-term interactions with a large variety of plants, thereby playing a significant role in natural and managed ecosystems and in evolution of land plants. To exploit plants as living substrates and to establish a compatible interaction with morphologically and biochemically extremely different hosts, endophytes must respond and adapt to different plant signals and host metabolic states. Here we identified host-adapted colonization strategies and host-specific effector candidates of the mutualistic root endophyte Piriformospora indica by a global investigation of fungal transcriptional responses to barley and Arabidopsis at different symbiotic stages. Additionally we examined the role played by nitrogen in these two diverse associations. Cytological studies and colonization analyses of a barley mutant and fungal RNAi strains show that distinct physiological and metabolic signals regulate host-specific lifestyle in P. indica. This is the foundation for exploring how distinct fungal and host symbiosis determinants modulate biotrophy in one host and saprotrophy in another host and, ultimately, gives hints into the mechanisms underlying host adaptation in root symbioses. Arabidopsis and barley roots were inoculated with Piriformospora indica and grown for 14 days. Additionally P. indica was grown on 1/10 PNM medium alone. Samples were taken 3 and 14 dpi (Arabidopsis), 14 dpi (barley) and 3dpi (1/10 PNM). Each experiment was performed in three independent biological repetitions. Piriformospora indica gene expression examined only.