Project description:Phosphorus (P) is an essential macronutrient for various biological processes in plant growth. Modern agricultural science has advanced the knowledge of regulatory mechanisms underlying phosphorus starvation responses (PSRs), aiming to develop phosphate-efficient crops with sustainable production under reduced Pi fertilizer application. However, information regarding coordinated shoot and root adaptation in response to combined nutrient stresses is limited. This study investigated the role of Phloem Phosphate Stress Repressed 1 (PPSR1) in modulating PSRs and other nutrient adaptation. The Arabidopsis functional homologue of Cucumis sativus PPSR1 (CsPPSR1), designated AtPPSR1, was identified. AtPPSR1 encodes a glycine-rich domain-containing protein, and its ectopic expression confers enhanced growth performance to plants. Transcriptomic analyses revealed AtPPSR1 as a regulatory mediator of PSRs, photosynthesis and root development. We revealed that AtPPSR1 interacted with PHOSPHATE STARVATION RESPONSE 1 (PHR1) to regulate PHR1-target genes for adaptive root development, in response to Pi-starvation stress. Additionally, AtPPSR1 was discovered as graft-transmissible, and the shoot-borne AtPPSR1 played a role in restoring the root phenotype of the ppsr1 mutant. Physiological analyses revealed that enhanced AtPPSR1 expression enabled resilience to nitrogen (N) and potassium (K)-starvation, as well as to Pi-deficiency. Furthermore, we identified homologues of CsPPSR1 and AtPPSR1 in Brassica napus (canola), which displayed similar expression patterns in response to Pi-starvation stress. Overexpression of PPSR1, identified from Arabidopsis, cucumber and canola, improved growth performance and seed yield in canola under N-, Pi- or K-deficient conditions. These findings provide novel insights into PPSR1-mediated molecular coordination to improve growth performance under mineral nutrient-stresses conditions.
Project description:RNASeq of roots from two genotypes of Arabidopsis thaliana plants, Col-0 and myb36-2 grown axenically or with a 41 member bacterial Synthetic Community (SynCom) to explore the interaction between the root diffusion barriers and the root microbiome.
Project description:To determine secreted proteins that involved in adaptation of nutrient sources and response to nutrient stresses, we analyzed transcriptomes of Pochonia chlamydosporia strain 170 under three different nutrient conditions, CD (nutrient rich medium) that was predicted to repress parasitism, MM (nutrient-poor liquid minimal medium) that was predicted de-repress genes associated with parasitism, and MM-eggs(minimal medium with root-knot nematode eggs) that was prepared to induce parasitism.
Project description:Chromatin modifications play important roles in plant adaptation to abiotic stresses, but the precise function of histone H3 lysine 36 (H3K36) methylation in drought tolerance remains poorly evaluated. Here, we report that SDG708, a specific H3K36 methyltransferase, functions as a positive regulator of drought tolerance in rice.
Project description:Here, we investigated the function of the plant-specific SR protein RS33 in pre-mRNA splicing regulation and abiotic stress responses in rice. The loss-of-function mutant, rs33, showed increased sensitivity to salt and low-temperature stress. Genome-wide analyses of gene expression and splicing in seedlings subjected to these stresses identified multiple splice isoforms from stress-responsive genes dependent on RS33. The number of RS33-regulated genes is much higher under low-temperature stress as compared to salt stress. Our results suggest that this plant-specific splicing factor plays crucial and distinct roles during plant adaptation to abiotic stresses.
Project description:We generated a comprehensive RNAseq expression atlas for several stress conditions in order to analyze changes in the gene expression during adaptation to mild stresses. The stresses are divided into two main groups: the “nutrient stresses” and the “environmental stresses”. Nutrient stresses include nutrient depletion (-N, -P, -S, -micronutrients), salt stress (+NaCl), osmotic stress (+mannitol) and control. The environmental stresses consist of high light, prolonged darkness, heat, cold and control.
Project description:Heat stress (HS) is often a recurring and constant threat to crop productivity worldwide. For optimal crop survival, a sensitive and dynamic balance between stress-response and growth-control is required. Previous studies have demonstrated unique properties of 22-nt siRNAs in plant adaptation to environmental stresses, yet much less is known about how DCL2 regulate mechanisms under stresses in detail. Here, we demonstrate that the production of 22-nt siRNAs, particularly from SMXL4/5, might be crucial for plants to adapt to HS.
Project description:Plant-derived smoke plays a key role in seed germination and plant growth. To investigate the effect of plant-derived smoke on chickpea, a gel-free/label-free proteomic technique was used. Germination percentage, root/shoot length, and fresh biomass were increased in chickpea treated with 2000 ppm plant-derived smoke within 6 days. On treatment with 2000 ppm plant-derived smoke for 6 days, the abundance of 90 proteins including glycolysis-related proteins significantly changed in chickpea root. Proteins related to signaling and transport were increased; however, proteins related to protein metabolism, cell, and cell wall were decreased. The sucrose synthase for starch degradation was increased and total soluble sugar was induced in chickpea. Similarly, the proteins for nitrate pathway were increased and nitrate content was improved in chickpea. On the other hand, although secondary metabolism related proteins were decreased, flavonoid contents were increased in chickpea. Based on proteomic and immuno-blot analyses, proteins related to redox homeostasis were decreased and increased in root and shoot, relatively. Furthermore, fructose-bisphosphate aldolase was increased; while, phosphotransferase and phosphoglyceromutase were decreased in glycolysis. These results suggest that plant-derived smoke improves early stage of growth in chickpea with the balance of many cascades such as glycolysis, redox homeostasis, and secondary metabolism.
Project description:Root exudates play major roles in the recruitment of plant microbiota. The metabolic composition of root exudates varies according to plant developmental stage, nutrient availability, (a)biotic stresses and interaction with the root-associated microbiota, including arbuscular mycorrhizal fungi (AMF), which play a key role in plant mineral nutrition and stress tolerance. While it is well established that AMF can perceive plant root exudate compounds, little is known about plant root exudate modifications in response to AMF inoculation. Here, we developed an aeroponic-based culture system suitable for the analysis of maize root exudates during symbiosis with the AMF Rhizophagus irregularis while controlling nutrient availability. We validated the functionality of the system by monitoring both maize root colonization by the AMF and the expression profile of symbiotic root marker genes. We then investigated the composition of root exudates (strigolactones and specialized metabolites) from mycorrhizal and non-mycorrhizal plants grown under different N and P regimes. Comparisons of specialized metabolite profiles from root exudates, root tissues, and fungal extracts allowed us to identify candidate metabolic features specifically accumulating in mycorrhizal root exudates. Thus, we provide an innovative method to better understand the role of root exudate metabolites in shaping the microbiota of mycorrhizal plants.