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: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:Although some mechanisms are known how plant growth beneficial bacteria help plants to grow under stressful conditions, we still know little how the metabolism of host plants and bacteria is coordinated during the establishment of functional interaction. In the present work, using single and dual transcriptomics, we studied the reprograming of metabolic and signaling pathways of Enterobacter sp. SA187 with Arabidopsis thaliana during the change from free-living to endophytic host-microbe interaction. We could identify major changes in primary and secondary metabolic pathways in both the host and bacteria upon interaction, with an important role of the sulfur metabolism and retrograde signaling in mediating plant resistance to salt stress. Also, we studied the effect of SA187 endogenous compounds and its role on sulfur metabolism and consequently salt tolerance. These data should help future research in the field of beneficial plant-microbe interactions for developing sophisticated strategies to improve agriculture of crops under adverse environmental conditions. transcriptome of Arabidopsis thaliana organs with beneficial microbe, beneficial microbe endogenous compound, and ethylene precursor
Project description:High ambient temperature regulated the plant systemic response to the beneficial endophytic fungus Serendipita indica. Most plants in nature establish symbiotic associations with endophytic fungi in soil. Beneficial endophytic fungi induce a systemic response in the aboveground parts of the host plant, thus promoting the growth and fitness of host plants. Meanwhile, temperature elevation from climate change widely affects global plant biodiversity as well as crop quality and yield. Over the past decades, great progresses have been made in the response of plants to high ambient temperature and to symbiosis with endophytic fungi. However, little is known about their synergistic effect on host plants. The endophytic fungus Serendipita indica colonizes the roots of a wide range of plants, including Arabidopsis. Based on the Arabidopsis-S. indica symbiosis experimental system, we analyzed the synergistic effect of high ambient temperature and endophytic fungal symbiosis on host plants. By transcriptome analysis, we found that DNA replication-related genes were significantly upregulated during the systemic response of Arabidopsis aboveground parts to S. indica colonization. Plant hormones, such as jasmonic acid (JA) and ethylene (ET), play important roles in plant growth and systemic responses. We found that high ambient temperature repressed the JA and ET signaling pathways of Arabidopsis aboveground parts during the systemic response to S. indica colonization in roots. Meanwhile, PIF4 is the central hub transcription factor controlling plant thermosensory growth under high ambient temperature in Arabidopsis. PIF4 is also involving JA and/or ET signaling pathway. We found that PIF4 target genes overlapped with many differentially expressed genes (DEGs) during the systemic response, and further showed that the growth promotion efficiency of S. indica on the pif4 mutant was higher than that on the wild type plants.
Project description:The model plant Arabidopsis thaliana responds to mild high temperature by increased elongation growth of organs to enhance cooling capacity, in a process called thermomorphogenesis. Our understanding of the genetic regulation of thermomorphogenesis has increased in recent years. However, hardly anything is known about molecular mechanisms outside A. thaliana and cellular signaling pathways have been underexplored. Therefore, we mapped changes in protein phosphorylation in A. thaliana and crops exposed to warm temperature. Based on these results, we identified and characterized a novel, functionally conserved signaling complex of MITOGEN-ACTIVATED PROTEIN KINASE KINASE KINASE KINASEs (MAP4KS) in warm temperature-mediated growth regulation in plants. This contributes to our understanding of warm temperature signaling, and can help guarantee food security under a changing climate.
Project description:The model plant Arabidopsis thaliana responds to mild high temperature by increased elongation growth of organs to enhance cooling capacity, in a process called thermomorphogenesis. Our understanding of the genetic regulation of thermomorphogenesis has increased in recent years. However, hardly anything is known about molecular mechanisms outside A. thaliana and cellular signaling pathways have been underexplored. Therefore, we mapped changes in protein phosphorylation in A. thaliana and crops exposed to warm temperature. Based on these results, we identified and characterized a novel, functionally conserved signaling complex of MITOGEN-ACTIVATED PROTEIN KINASE KINASE KINASE KINASEs (MAP4KS) in warm temperature-mediated growth regulation in plants. This contributes to our understanding of warm temperature signaling, and can help guarantee food security under a changing climate
Project description:The intricate interactions between plants and microorganisms have garnered substantial scientific interest. While previous studies have highlighted the potential influence of various fungal volatile compounds(VCs) on plant growth and development, the precise mechanisms underlying this modulation still need to be discovered. In this study, we discovered that fungal volatile organic compounds from the soil-borne fungus Tolypocladium inflatum GT22 enhance the growth of Arabidopsis. Remarkably, following the priming of Arabidopsis with GT22 VC, it displayed an enhanced immune response, thereby mitigating the detrimental effects caused by both pathogenic infections and copper stress. Transcriptomic analyses of Arabidopsis seedlings treated with GT22 VCs revealed the differential expression of 90, 83, and 137 genes after 3, 24, and 48 hours of volatile exposure, respectively. These responsive genes are involved in growth, hormone regulation, defense mechanisms, and signaling pathways. Notably, the induction of genes related to innate immunity, hypoxia, salicylic acid (SA) biosynthesis and camalexin biosynthesis by GT22 VCs were reported. Among the VCs emitted by GT22, limonene is particularly noteworthy. Arabidopsis seedlings exposed to limonene exhibited not only growth promotion effects but also alleviation of copper stress, indicating that limonene may play a role in the interaction between GT22 and plants. Overall, the findings of this study provide evidence supporting that fungal VCs can promote plant growth and enhance both biotic and abiotic tolerance. Furthermore, our results suggest that seedlings exposed to T. inflatum GT22 VCs holds promising potential for harnessing beneficial effects to improve crop productivity.