Project description:Genome-wide Transcriptional Analysis of Genes Associated with Drought Stress in Gossypium herbaceum root This experiment was designed to investigate the molecular mechanism associated with drought tolerance in root tissue of Gossypium herbaceum. The gene expression profiles of the root tissue using Affymetrix Cotton Genome Array were compared with drought tolerant and drought sensitive genotype of G.herbaceum under drought stress and watered condition. Many genes in various molecular function or biological processes were over- or under-represented between drought tolerant and sensitive genotype, suggesting various molecular mechanism and biochemical pathways are interlinked and tolerant genotype have developed multiple mechanisms as an adaptory behavior against drought stress.
Project description:The secretion of metabolites by plant roots is a key determinant of microbial growth and colonisation. We have used Pisum sativum and its natural symbiont Rhizobium leguminosarum (it can form N2 fixing nodules on pea roots) to study the natural metabolites secreted by roots. To do this root secretion was harvested from pea plants grown under sterile conditions. This root exudate was then concentrated and used as a sole carbon and nitrogen source for growth of the bacteria in the laboratory. These bacteria were harvested in mid-exponential growth and RNA extracted for microarray analysis. As control cultures the bacteria were grown on 30 mM pyruvate as a carbon source and 10 mM ammonium chloride as a nitrogen source and RNA extracted. Two colour microarrays were performed using root exudate cultures versus pyruvate ammonia grown cultures. This was done in biological triplicate.
Project description:Genome-wide Transcriptional Analysis of Genes Associated with Drought Stress in Gossypium herbaceum root This experiment was designed to investigate the molecular mechanism associated with drought tolerance in root tissue of Gossypium herbaceum. The gene expression profiles of the root tissue using Affymetrix Cotton Genome Array were compared with drought tolerant and drought sensitive genotype of G.herbaceum under drought stress and watered condition. Many genes in various molecular function or biological processes were over- or under-represented between drought tolerant and sensitive genotype, suggesting various molecular mechanism and biochemical pathways are interlinked and tolerant genotype have developed multiple mechanisms as an adaptory behavior against drought stress. The transcriptional responses of root tissue in drought tolerant and sensitive genotype of Gossypium herbaceum under drought stress have been investigated. Physiological responses to drought stress, such as stomatal conductance, water use efficiency, root bending assay on different mannitiol concentration were also measured as indicators of imposed drought stress. Total RNA was isolated from root tissue from both genotype under drought stress and normal irrigated condition with three biological replicates
Project description:Since the roots of grapevine rootstocks have a direct contact with drying soil and has an important role in abiotic stimuli, any plasticity on the architecture of the rootstocks would enable grapevine varieties to a better respond to drought stress. However, genomics evidences behind the physiological responses of rootstocks under prolonged drought stress are poorly documented in the literature. In the current study, eight widely used hybrid grapevine rootstocks in viticulture were firstly grafted with sultana seedless and subjected to drought stress to test their physiological and biochemical responses. The results of experiment indicated that the roots of V.rupestris X V.berlandieri (110 R, 1103P, 140 Ru) rootstocks possessed much higher water content as well as non-structural carbohydrate and nitrogen concentrations compared to V.riparia X V.berlandieri (SO4, 5BB, 420A, 8B) and V.vinifera X V.berlandieri (41B) hybrids under drought. V.rupestris X V.berlandieri hybrids were also performed much higher root elongation performance under drought compared to other rootstock hybrids. Three rootstock varieties (110R, 5BB and 41B) having different pedigrees and root architectural responses to drought were also investigated at transcriptome level to find out gene regulation network behind differential physiological responses to drought. Transcriptome analysis revealed 2795, 1196 and 1612 differentially expressed transcripts for the roots of 110R, 5BB and 41B, respectively. The highest expression increases in 110R compared to other rootstocks were recorded for the transcripts functional in carbohydrate (SWEET14, CWINV) and nitrate/peptide (NRT1/ PTR FAMILY) transportation as well as osmoregulation (dehydrins, osmotins, LEAs and proline-glycine rich proteins) during drought. Higher induction of these genes in the roots of tolerant 110R genotype indicated importance of efficient uptake of carbohydrate and nitrogen source released from canopy under drought and preservation of water with osmotic regulation on the root elongation and drought tolerance of grapevines. Expression increases in several other pathogenesis related proteins, regulation of cell wall modification enzymes and activity of several secondary metabolites have been also associated to altered root architecture and drought tolerance in the grapevine rootstocks for the first time with the current study.
Project description:Anthropogenic nitrogen (N) deposition may affect soil organic carbon (SOC) decomposition, thus affecting the global terrestrial carbon (C) cycle. However, it remains unclear how the level of N deposition affects SOC decomposition by regulating microbial community composition and function, especially C-cycling functional genes structure. We investigated the effects of short-term N addition on soil microbial C-cycling functional gene composition, SOC-degrading enzyme activities, and CO2 emission in a 5-year field experiment established in an artificial Pinus tabulaeformis forest on the Loess Plateau, China.
Project description:OsNAC6 is a stress responsive NAC transcription factor in rice known as a regulator for the transcriptional networks of the drought tolerance mechanisms. However, little is known about the associated molecular mechanisms for drought tolerance. Here, we identified OsNAC6-mediated root structural adaptation such as increased root number and root diameter that was sufficient to confer drought tolerance. Multiyear (5 years) drought field tests clearly demonstrated that OsNAC6 overexpression in roots produced higher grain yield under drought conditions. Genome-wide analyses revealed that OsNAC6 directly up-regulated 13 genes. Taken together, OsNAC6 is a valuable candidate for genetic engineering of drought-tolerant high-yielding crops.
Project description:OsNAC6 is a stress responsive NAC transcription factor in rice known as a regulator for the transcriptional networks of the drought tolerance mechanisms. However, little is known about the associated molecular mechanisms for drought tolerance. Here, we identified OsNAC6-mediated root structural adaptation such as increased root number and root diameter that was sufficient to confer drought tolerance. Multiyear (5 years) drought field tests clearly demonstrated that OsNAC6 overexpression in roots produced higher grain yield under drought conditions. Genome-wide analyses revealed that OsNAC6 directly up-regulated 13 genes. Taken together, OsNAC6 is a valuable candidate for genetic engineering of drought-tolerant high-yielding crops.
Project description:Grafting is a well-established practice for grapevine to facilitate propagation of productive and tolerant cultivars against several stress factors. It is also considered to be a suitable method for studying molecular aspects of root-to-shoot and/or shoot-to-root signaling events. So far, controlling only effect of rootstock over scion was investigated and root-to-shoot transcriptomic alterations were fallowed on the scions or graft interfaces. The objective of this study was to investigate transcriptomic and physiological influence of scion on the rootstock under drought stress. Therefore, drought tolerant 110R rootstock were firstly grafted with sultana seedless and tested under drought stress with its non-grafted counterpart. The results of treatment indicated that grafted 110R performed the highest root elongation under drought. We carried out a microarray based transcriptome analysis on the roots of grafted and non-grafted 110R to explain this drought derived interaction through scion-to-rootstock. The highest expression increase under drought was recorded for sugar (SWEET) and nitrate or di/tri-peptide (NRT1/ PTR FAMILY) transporter proteins. Expression level of these genes was more highly increased in grafted 110R than its non-grafted counterpart. This situation indicated their potential role in drought tolerance and scion/rootstock harmony. Overexpression of these transporters attributed to increased amount of released nutrient and nitrogen source from abscised leaves of sultana seedless under drought. Remobilization of these rich sources was suggested to chance transcriptomic response of rootstocks and enabled much better growth in grafted 110R. Other transcripts annotated to cell wall modification enzymes (chitinases), osmoregulator proteins (dehydrins, proline-glycine rich proteins) and secondary metabolites (stilbene synthase) were also more highly induced in grafted 110R. This is the first report indicating transcriptomic influence of scion on the grapevine rootstocks and representing the genes responsible in scion/rootstock harmony and drought tolerance.
Project description:Plant responses to drought stress require the regulation of transcriptional networks via drought responsive transcription factors, which mediate a range of morphological and physiological changes. AP2/ERF transcription factors are known to act as key regulators of drought resistance transcriptional networks; however, little is known about the associated molecular mechanisms that give rise to specific morphological and physiological adaptations. In this study, we functionally characterized the rice (Oryza sativa) drought responsive AP2/ERF transcription factor, OsERF71, which is predominantly expressed in the root meristem, pericycle, and endodermis. Overexpression of OsERF71 either throughout the entire plant or specifically in roots, resulted in a drought resistance phenotype at the vegetative growth stage, indicating that overexpression in roots was sufficient to confer drought resistance. The root specific overexpression was more effective in conferring drought resistance at the reproductive stage, such that grain yield was increased by 23-42% over wild type plants or whole-body overexpressing transgenic lines under drought conditions. OsERF71 overexpression in roots elevated the expression levels of genes related to cell wall loosening and lignin biosynthetic genes, which correlated with changes in root structure, the formation of enlarged aerenchyma and high lignification levels. Furthermore, OsERF71 was found to directly bind to the promoter of OsCCR1, a key gene in lignin biosynthesis. These results indicate that the OsERF71-mediated drought resistance pathway recruits factors involved in cell wall modification to enable root morphological adaptations, thereby providing a mechanism for enhancing drought resistance.
Project description:The present dataset is composed of Lotus japonicus root exudate samples under different nitrogen states: starved (no nitrogen), inorganic N (KNO3), symbiotic N (inoculation with M. loti), and inorganic/symbiotic (KNO3 + M. loti). The samples were analyzed by ultra-high-performance liquid chromatography (UHPLC) coupled to a quadrupole time-of-flight mass spectrometer (qToF MS, Bruker Compact) with electrospray ionization.