Project description:Temperature passively affects many biological processes. It is therefore challenging to study dedicated temperature signalling pathways orchestrating plant thermomorphogenesis; a suite of elongation growth-based adaptations that enhance leaf cooling capacity. Following a chemical genetics approach, we screened a chemical library for compounds that restored abolished hypocotyl elongation in the pif4-2 deficient mutant background in the model plant Arabidopsis thaliana. The small aromatic compound ‘Heatin' (N'-[(2-hydroxy-1-naphthyl)methylene]-2-(1-naphthylamino)propanohydrazide), with 1-aminomethyl-2-naphthol, as minimal active moiety, was isolated as potent enhancer of elongation growth. Here we assessed the transcriptomic changes induced by the compound, by supplementing the MS-agar growth medium with Heatin compared to DMSO solvent, in whole seedlings of the Col-0 wild type background in control (22oC) and high ambient temperature conditions (27oC).
Project description:Plant growth regulators are the chemical substances that regulate growth and development in plants. The use of plant growth regulators on crops can adjust the balance of hormones and influence plant growth, thereby increasing crop yield and/or improving crop quality. Fubianliusuoyoumi (GZU001), a new potential plant growth regulator, significantly promoted root elongation in maize. However, an underlying potential mechanism is still unknown. To explore the response pathway and regulation mechanism of GZU001 in promoting maize root elongation, a combination of metabolomics and proteomics was used. In total, 101 differentially expressed proteins (DEPs) and 79 differentially expressed metabolites were identified. Our study found that four photosynthetic proteins (COPAQ4, P48183, B4FRH1, and A0A3L6EQ36) were significantly up-regulated, which can promote photosynthesis in maize.
Project description:The regulation of plant biomass degradation by fungi is critical to the carbon cycle, and applications in bioproducts and biocontrol. Trichoderma harzianum is an important plant biomass degrader, enzyme producer, and biocontrol agent, but few putative major transcriptional regulators have been deleted in this species. The T. harzianum ortholog of the transcriptional activator XYR1/XlnR/XLR-1 was deleted, and the mutant strains were analyzed by growth profiling, enzymatic activities, and transcriptomics on cellulose. From plate cultures, the Δxyr1 mutant had reduced growth on D-xylose, xylan, and cellulose, and from shake-flask cultures with cellulose, the Δxyr1 mutant had ~ 90% lower β-glucosidase activity, and no detectable β-xylosidase or cellulase activity. The comparison of the transcriptomes from 18 h shake-flask cultures on D-fructose, without a carbon source, and cellulose, showed major effects of XYR1 deletion whereby the Δxyr1 mutant on cellulose was transcriptionally most similar to the cultures without a carbon source. The cellulose induced 43 plant biomass-degrading CAZymes including xylanases as well as cellulases, and most of these had massively lower expression in the Δxyr1 mutant. Expression of a sub-set of carbon catabolic enzymes, other transcription factors, and sugar transporters was also lower in the Δxyr1 mutant on cellulose. In summary, T. harzianum XYR1 is the master regulator of cellulases and xylanases, as well as regulating carbon catabolic enzymes.
Project description:Pseudomonas fluorescens strain SS101 (Pf.SS101) promotes growth of Arabidopsis thaliana, enhances greening and lateral root formation, and induces systemic resistance (ISR) against the bacterial pathogen Pseudomonas syringae pv. tomato (Pst). Here, targeted and untargeted approaches were adopted to identify bacterial determinants and underlying mechanisms involved in plant growth promotion and ISR by Pf.SS101. Based on targeted analyses, no evidence was found for volatiles, lipopeptides and siderophores in plant growth promotion by Pf.SS101. Untargeted, genome-wide analyses of 7,488 random transposon mutants of Pf.SS101 led to the identification of 21 mutants defective in both plant growth promotion and ISR. Many of these mutants, however, were auxotrophic and impaired in root colonization. Genetic analysis of three mutants followed by site-directed mutagenesis, genetic complementation and plant bioassays revealed the involvement of the phosphogluconate dehydratase gene edd, the response regulator gene colR and the adenylsulfate reductase gene cysH in both plant growth promotion and ISR. Subsequent comparative plant transcriptomics analyses strongly suggest that modulation of sulfur assimilation, auxin biosynthesis and transport, steroid biosynthesis and carbohydrate metabolism in Arabidopsis are key mechanisms linked to growth promotion and ISR by Pf.SS101. Comparative transcriptome analysis of Arabidopsis treated with Pf. SS101, a growth and ISR promoting rhizobacteria and plants treated with cysH mutant of Pf.SS101 that fails to induce the afformentioned phenotypes
Project description:Plants balance their conflicting requirements for growth and stress tolerance via sophisticated pathways and unique genes that control responses to the external environment. We have identified a novel plant-specific gene, COST1(Constitutively Stressed 1), that affects plant growth and negatively regulates drought resistance by manipulating the autophagy pathway. An Arabidopsis cost1 mutant has decreased growth and increased drought tolerance, together with constitutive autophagy and increased expression of drought-response genes. The COST1 protein is degraded upon plant dehydration, and this degradation is blocked by treatment with inhibitors of the 26S proteasome or autophagy pathways. The cost1 mutant drought resistance is dependent on an active autophagy pathway, indicating that COST1 acts through manipulation of autophagy. COST1 co-localizes to autophagosomes with the autophagosome marker ATG8e and the autophagy adaptor NBR1, and physically interacts with ATG8e, indicating a pivotal role in direct regulation of autophagy. We propose a model in which COST1 represses autophagy under optimal conditions, thus allowing plant growth. During drought, COST1 is degraded, enabling activation of autophagy and suppressing growth to enhance drought tolerance.
Project description:Possitive effects of plant growth promoting bacteria (PGPB) inoculation on plant growth and development are dependent on interaction between bacterial strains and plant roots, which are usually the bacterial niche. Furthermore, phytohormones are key regulators of plant physiology. Ethylene is essential in plant growth and development and in response to drought. Plant sensibility to ethylene is involved in plant response to PGPB strain inoculation and plant growth promotion. We used microarrays to detail the global programme of gene expression underlying plant interaction with two different PGPB strains (isolated from arid soils in southern Spain) regarding to plant sentitivity to ethylene by tomato ethylene receptor 3 (SlETR3).
Project description:Sun-loving plants have the ability to detect and avoid shading through sensing of both blue and red light wavelengths. Higher plant cryptochromes (CRYs) control how plants modulate growth in response to changes in blue light. For growth under a canopy, where blue light is diminished, CRY1 and CRY2 perceive this change and respond by directly contacting two bHLH transcription factors, PIF4 and PIF5. These factors are also known to be controlled by phytochromes, the red/far-red photoreceptors; however, transcriptome analyses indicate that the gene regulatory programs induced by the different light wavelengths are distinct. Our results indicate that CRYs signal by modulating PIF activity genome-wide, and that these factors integrate binding of different plant photoreceptors to facilitate growth changes under different light conditions.