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Results for “PLANT GROWTH”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 19 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2015

Arabidopsis MSH1 mutation alters the epigenome and produces heritable changes in plant growth

Plant phenotypes respond to environmental change, an adaptive capacity that is at least partly transgenerational. However, epigenetic components of this interplay are difficult to measure. Depletion of the nuclear-encoded protein MSH1 causes dramatic and heritable changes in plant development, and here we show that crossing these altered plants with isogenic wild type produces epi-lines with heritable, enhanced growth vigour. Pericentromeric DNA hypermethylation occurs in a subset of msh1 mutants, indicative of heightened transposon repression, while enhanced growth epi-lines show large chromosomal segments of differential CG methylation, reflecting genome-wide reprogramming. When seedlings are treated with 5-azacytidine, root growth of epi-lines is restored to wild-type levels, implicating hypermethylation in enhanced growth. Grafts of wild-type floral stems to mutant rosettes produce progeny with enhanced growth and altered CG methylation strikingly similar to epi-lines, indicating a mobile signal when MSH1 is downregulated, and confirming the programmed nature of methylome and phenotype changes

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2021

Plant Growth Study: Growth of Three Plant Species in 100-OL-1 Operable Unit Soils

Soil contamination from historical application of lead arsenate pesticides persists in the 100-OL-1 Operable Unit (OU) of the U.S. Department of Energy’s Hanford Site in Benton County, Washington. A remedial investigation used a portable X-ray fluorescence analyzer to estimate and map the concentrations of metals in surface soil in the 133 decision units comprising the OU. There is variability in lead and arsenic concentrations among the non-contiguous decision units, and an incomplete understanding of the ecological and human risks from soil contamination. While general screening criteria for lead are reported in literature, limited information is available on the impacts of heavy metals on site-specific plant and animal life. To address this information gap, a study on plant growth in Hanford soils was conducted using native bluegrass (Poa secunda), invasive cheatgrass (Bromus tectorum), and buttercrunch lettuce (Lactuca sativa). The latter is included because it is a common species used in plant growth studies. Soil samples were collected from a single general location within the 100-OL-1 OU, prepared, and categorized as having low, medium, or high concentrations of lead and arsenic, with the high concentration soil having concentrations of up to 3,400 and 790 mg/kg lead and arsenic, respectively. Additionally, a synthetic soil was prepared and used as a control, in accordance with standard plant growth protocols. Fifty-four seeds of each plant species were planted in each of the four soil types following the procedure outlined by the Washington State Department of Ecology. Germination rates and biomass measurements were recorded for 20 days. Both bluegrass and lettuce germination rates appeared to be reduced at the highest lead and arsenic concentrations (Pb: 3400 mg/kg, As: 790 mg/kg), while cheatgrass germination rates were unaffected. Total biomass for all species appeared to be related to the relative concentrations of lead and arsenic in the soil. Results of this growth study agree reasonably well with previous Hanford Site plant growth studies and provide additional data for assessing ecological risk at the Hanford Site.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2016

Overexpression of an Arabidopsis heterogeneous nuclear ribonucleoprotein gene, AtRNP1, affects plant growth and reduces plant tolerance to drought and salt stresses

Heterogeneous nuclear ribonucleoproteins (hnRNPs) participate in diverse regulations of plant growth and environmental stress responses. In this work, an Arabidopsis hnRNP of unknown function, AtRNP1, was investigated. We found that AtRNP1 gene is highly expressed in rosette and cauline leaves, and slightly induced under drought, salt, osmotic and ABA stresses. AtRNP1 protein is localized to both the nucleus and cytoplasm. We performed homologous overexpression of AtRNP1 and found that the transgenic plants showed shortened root length and plant height, and accelerated flowering. In addition, the transgenic plants also showed reduced tolerance to drought, salt, osmotic and ABA stresses. Further studies revealed that under both normal and stress conditions, the proline contents in the transgenic plants are markedly decreased, associated with reduced expression levels of a proline synthase gene and several stress-responsive genes. These results suggested that the overexpression of AtRNP1 negatively affects plant growth and abiotic stress tolerance. - Highlights: • AtRNP1 is a widely expressed gene and its expression is slightly induced under abiotic stresses. • AtRNP1 protein is localized to both the nucleus and cytoplasm. • Overexpression of AtRNP1 affects plant growth. • Overexpression of AtRNP1 reduces plant tolerance to drought and salt stresses. • AtRNP1 overexpression plants show decreased proline accumulation and stress-responsive gene expressions.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2013

Complete Genome Sequence of Micromonospora Strain L5, a Potential Plant-Growth-Regulating Actinomycete, Originally Isolated from Casuarina equisetifolia Root Nodules

Micromonospora species live in diverse environments and exhibit a broad range of functions, including antibiotic production, biocontrol, and degradation of complex polysaccharides. To learn more about these versatile actinomycetes, we sequenced the genome of strain L5, originally isolated from root nodules of an actinorhizal plant growing in Mexico.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2020

Ectomycorrhizal fungal diversity interacts with soil nutrients to predict plant growth despite weak plant-soil feedbacks

Background and aims Plant-soil feedbacks are the result of multiple abiotic and biotic mechanisms. However, few studies have addressed how feedbacks vary based on abiotic context or attempted to identify microbiota responsible for feedbacks. In this work, we investigated whether plant-soil feedbacks of an ectomycorrhizal tree (Quercus macrocarpa) varied based on soil nutrient status and whether fungal community composition and diversity could explain feedback patterns. Furthermore, we inoculated Q. macrocarpa seedlings with field-sampled soils taken from five soil origins – including heterospecific and conspecific trees and an old field – which were profiled using fungal DNA metabarcoding.Results Despite finding that soils associated with different hosts harbored distinct fungal communities and that fungal communities were predictive of plant growth, we did not find any significant plant-soil feedbacks regardless of fertilization status. We did find that the growth promotive effect associated with ectomycorrhizal OTU diversity was weakened with fertilization, suggesting context-dependent relations between plant growth and a guild of fungal mutualists. Our results demonstrate that the host-specific accumulation of functionally important soil microbes is not always sufficient to drive observable plant-soil feedbacks. Our data provide support for a role for ECM fungal diversity in mediating plant growth responses, though it is unclear whether this effect is direct or indirect.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2014

Overexpression of patatin-related phospholipase AIIIδ altered plant growth and increased seed oil content in camelina

Camelina sativa is a Brassicaceae oilseed species being explored as a biofuel and industrial oil crop. A growing number of studies have indicated that the turnover of phosphatidylcholine plays an important role in the synthesis and modification of triacylglycerols. This study manipulated the expression of a patatin-related phospholipase AIIIδ ( pPLAIIIδ ) in camelina to determine its effect on seed oil content and plant growth. Constitutive overexpression of pPLAIIIδ under the control of the constitutive cauliflower mosaic 35S promoter resulted in a significant increase in seed oil content and a decrease in cellulose content. In addition, the content of major membrane phospholipids, phosphatidylcholine and phosphatidylethanolamine, in 35S::pPLAIIIδ plants was increased. However, these changes in 35S::pPLAIIIδ camelina were associated with shorter cell length, leaves, stems, and seed pods and a decrease in overall seed production. When pPLAIIIδ was expressed under the control of the seed specific, β-conglycinin promoter, the seed oil content was increased without compromising plant growth. In conclusion, the results suggest that pPLAIIIδ alters the carbon partitioning by decreasing cellulose content and increasing oil content in camelina.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2020

Methods and apparatus for gnotobiotic plant growth

The disclosure relates to a plant growth apparatus and related system to grow and maintain plants under controlled biotic conditions, for example to grow axenic (microbe-free) plants, gnotobiotic (defined microbiota) plants, and holoxenic (complex, or undefined microbiota) plants. This system allows aseptic bottom irrigation with water, soluble nutrients, chemicals, and/or microbiota. Plants can be inverted for dipping and/or vacuum infiltration. The system also allows for passive (gravity) drainage, thereby allowing for gas exchange and preventing root anoxia. A variety of plant growth substrates can be used within the plant growth apparatus as a plant growth medium. The plant growth apparatus, containing the growth substrate medium, can be completely flushed via the drainage port to remove potential toxic byproducts of the sterilization processes. The entire system is suitably constructed using autoclavable material.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2022

Novel Mutant Alleles Reveal a Role of the Extra-Large G Protein in Rice Grain Filling, Panicle Architecture, Plant Growth, and Disease Resistance

Plant growth and grain filling are the key agronomical traits for grain weight and yield of rice. The continuous improvement in rice yield is required for a future sustainable global economy and food security. The heterotrimeric G protein complex containing a canonical α subunit (RGA1) couples extracellular signals perceived by receptors to modulate cell function including plant development and grain weight. We hypothesized that, besides RGA1, three atypical, extra-large GTP-binding protein (XLG) subunits also regulate panicle architecture, plant growth, development, grain weight, and disease resistance. Here, we identified a role of XLGs in agronomic traits and stress tolerance by genetically ablating all three rice XLGs individually and in combination using the CRISPR/Cas9 genome editing in rice. For this study, eight (three single, two double, and three triple) null mutants were selected. Three XLG proteins combinatorically regulate seed filling, because loss confers a decrease in grain weight from 14% with loss of one XLG and loss of three to 32% decrease in grain weight. Null mutations in XLG2 and XLG4 increase grain size. The mutants showed significantly reduced panicle length and number per plant including lesser number of grains per panicle compared to the controls. Loss-of-function of all individual XLGs contributed to 9% more aerial biomass compared to wild type (WT). The double mutant showed improved salinity tolerance. Moreover, loss of the XLG gene family confers hypersensitivity to pathogens. Our findings suggest that the non-canonical XLGs play important roles in regulating rice plant growth, grain filling, panicle phenotype, stress tolerance, and disease resistance. Genetic manipulation of XLG s has the potential to improve agronomic properties in rice.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2015

Spatial arrangement of canopy structure and land-use history alter the effect that herbivores have on plant growth

The spatial arrangement of past and present human activities could affect the strength of species interactions through changes to environmental conditions. To better understand how land-use history might mediate the effect of insect herbivory on the growth of four herbaceous plant species at the edges between woodlands and open savannas, we coupled large-scale manipulations of canopy structure by thinning overstory trees to create savanna habitat in non-agricultural and post-agricultural longleaf pine woodlands with local-scale herbivore exclosures at two distances from habitat edges. Light availability, grasshopper abundance, and herbaceous plant cover all increased in patches that received overstory tree thinning. Land-use history altered the effect that edges created by the overstory thinning treatments had on grasshopper herbivory for one plant species (Carphephorus bellidifolius). The edge between land-use histories also altered herbivore effects on three plant species in thinned patches. These edge effects were driven in part by changes in availability of alternative resources for grasshoppers, shady edges, or grasshopper abundance. Canopy manipulation also had important effects on herbivory that were independent of the habitat edge: grasshopper herbivory reduced plant growth of the smallest species (C. bellidifolius) regardless of canopy manipulation, whereas herbivory on two larger species (Solidago nemoralis and So. odora) reduced plant growth mainly in patches with an intact overstory canopy. Collectively, this work suggests that the species-specific effects of grasshopper herbivory on plant growth were driven by both plant traits (e.g., size or growth rates) and landscape-mediated changes to grasshopper abundance, light availability, or availability of alternative resources for grasshoppers created by land-use history and canopy structure. Furthermore, because the heterogeneity in herbivory revealed by our large-scale experiment is likely linked to plant traits, our results provide a means for understanding the profound, but often idiosyncratic, effects of land-use legacies and edges on plant populations and communities.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2014

Connections between Student Explanations and Arguments from Evidence about Plant Growth

We investigate how students connect explanations and arguments from evidence about plant growth and metabolism—two key practices described by the Next Generation Science Standards. This study reports analyses of interviews with 22 middle and high school students postinstruction, focusing on how their sense-making strategies led them to interpret—or misinterpret—scientific explanations and arguments from evidence. The principles of conservation of matter and energy can provide a framework for making sense of phenomena, but our results show that some students reasoned about plant growth as an action enabled by water, air, sunlight, and soil rather than a process of matter and energy transformation. These students reinterpreted the hypotheses and results of standard investigations of plant growth, such as van Helmont's experiment, to match their own understanding of how plants grow. Only the more advanced students consistently interpreted mass changes in plants or soil as evidence of movement of matter. We also observed that a higher degree of scaffolding during some of the interview questions allowed mid-level students to improve their responses. We describe our progress and challenges developing teaching materials with scaffolding to improve students’ understanding of plant growth and metabolism.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2012

Complete genome sequence of the rapeseed plant-growth promoting Serratia plymuthica strain AS9

Serratia plymuthica are plant-associated, plant beneficial species belonging to the family Enterobacteriaceae. The members of the genus Serratia are ubiquitous in nature and their life style varies from endophytic to free-living. S. plymuthica AS9 is of special interest for its ability to inhibit fungal pathogens of rapeseed and to promote plant growth. The genome of S. plymuthica AS9 comprises a 5,442,880 bp long circular chromosome that consists of 4,952 protein-coding genes, 87 tRNA genes and 7 rRNA operons. This genome is part of the project entitled Genomics of four rapeseed plant growth promoting bacteria with antagonistic effect on plant pathogens awarded through the 2010 DOE-JGI Community Sequencing Program (CSP2010).

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2015

Mining the phytomicrobiome to understand how bacterial coinoculations enhance plant growth

In previous work, we showed that coinoculating Rhizobium leguminosarum bv. viciae 128C53 and Bacillus simplex 30N-5 onto Pisum sativum L. roots resulted in better nodulation and increased plant growth. We now expand this research to include another alpha-rhizobial species as well as a beta-rhizobium, Burkholderia tuberum STM678. We first determined whether the rhizobia were compatible with B. simplex 30N-5 by cross-streaking experiments, and then Medicago truncatula and Melilotus alba were coinoculated with B. simplex 30N-5 and Sinorhizobium (Ensifer) meliloti to determine the effects on plant growth. Similarly, B. simplex 30N-5 and Bu. tuberum STM678 were coinoculated onto Macroptilium atropurpureum . The exact mechanisms whereby coinoculation results in increased plant growth are incompletely understood, but the synthesis of phytohormones and siderophores, the improved solubilization of inorganic nutrients, and the production of antimicrobial compounds are likely possibilities. Because B. simplex 30N-5 is not widely recognized as a Plant Growth Promoting Bacterial (PGPB) species, after sequencing its genome, we searched for genes proposed to promote plant growth, and then compared these sequences with those from several well studied PGPB species. In addition to genes involved in phytohormone synthesis, we detected genes important for the production of volatiles, polyamines, and antimicrobial peptides as well as genes for such plant growth-promoting traits as phosphate solubilization and siderophore production. Experimental evidence is presented to show that some of these traits, such as polyamine synthesis, are functional in B. simplex 30N-5, whereas others, e.g., auxin production, are not.

Plant Sciences↗
DOE OSTI2018

Cr3+ doped ZnGa2O4 far-red emission phosphor-in-glass: Toward high-power and color-stable plant growth LEDs with responds to all of phytochrome

Highlights: • A high-power and color-stable far-red emission phosphor-convertor LEDs is proposed. • The Cr{sup 3+} ion as the center of luminescence not only increase choice in plant lighting but also provides far-red light. • The ZGO:Cr{sup 3+}-PiG shows a quantum efficiency of ∼52.8%. • The high-power plant growth LEDs was fabricated, triggering providing broad spectral range for plant growth LEDs. - Abstract: In present work, a series of luminescent glass ceramic plates were prepared via phosphor-in-glass (PiG) technology, in which included the phosphor of ZnGa{sub 2}O{sub 4}:Cr{sup 3+} (ZGO:Cr{sup 3+}) and glass host with composition of 30SiO{sub 2}-30ZnO-22B{sub 2}O{sub 3}-12BaO-6Al{sub 2}O{sub 3} as matrix. The structure of ZnGa{sub 2}O{sub 4}:Cr{sup 3+}-based PiG (ZGO:Cr{sup 3+}-PiG) samples are characterized by powder X-ray diffraction, scanning electron microscope, and energy dispersive spectrometer mapping. These phosphors are found to be embedded in glass matrix without interfacial reaction. In addition, the ZGO:Cr{sup 3+}-PiG sample shows a quantum efficiency of ∼52.8% and its fluorescence intensity maintains 68.2% when temperature reaching 150 °C. Finally, high-power and color-stable far-red emission plant growth LEDs was fabricated by ZGO:Cr{sup 3+}-PiG and 400 nm near-UV LED chip, which spectra matches well the absorption of plant's photosynthetic pigments. More importantly, it responds to all of phytochrome, triggering providing broad spectral range for plant growth LEDs.

36 MATERIALS SCIENCE↗
DOE OSTI2012

Function of phloem-borne information macromolecules in integrating plant growth & development

Studies on higher plants have revealed the operation of cell-to-cell and long-distance communication networks that mediate the transport of information macromolecules, such as proteins and RNA. Based on the findings from this DOE-funded project and results from other groups, it is now well established that the enucleate sieve tube system of the angiosperms contains a complex set of proteins including RNA binding proteins as well as a unique population of RNA molecules, comprised of both mRNA and small RNA species. Hetero-grafting experiments demonstrated that delivery of such RNA molecules, into the scion, is highly correlated with changes in developmental phenotypes. Furthermore, over the course of this project, our studies showed that plasmodesmata and the phloem are intimately involved in the local and systemic spread of sequence-specific signals that underlie gene silencing in plants. Major advances were also made in elucidating the underlying mechanisms that operate to mediate the selective entry and exit of proteins and RNA into and out of the phloem translocation stream. Our pioneering studies identified the first plant protein with the capacity to both bind specifically to small RNA molecules (si-RNA) and mediate in the cell-to-cell movement of such siRNA. Importantly, studies conducted with support from this DOE program also yielded a detailed characterization of the first phloem-mobile RNP complex isolated from pumpkin, namely the CmRBP50-RNP complex. This RNP complex was shown to bind, in a sequence-specific manner, to a set of transcripts encoding for transcription factors. The remarkable stability of this CmRBP50-RNP complex allows for long-distance delivery of bound transcripts from mature leaves into developing tissues and organs. Knowledge gained from this project can be used to exert control over the long-distance signaling networks used by plants to integrate their physiological and developmental programs at a whole plant level. Eventually, this information will aid in the engineering of elite plant lines with optimal traits for plant growth under non-ideal conditions, enhanced biomass and/or seed yield, and directed carbon allocation for efficient and sustainable biofuels production.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2020

Maize ANT1 modulates vascular development, chloroplast development, photosynthesis, and plant growth

Arabidopsis AINTEGUMENTA (ANT), an AP2 transcription factor, is known to control plant growth and floral organogenesis. In this study, our transcriptome analysis and in situ hybridization assays of maize embryonic leaves suggested that maize ANT1 (ZmANT1) regulates vascular development. To better understand ANT1 functions, we determined the binding motif of ZmANT1 and then showed that ZmANT1 binds the promoters of millet SCR1, GNC, and AN3, which are key regulators of Kranz anatomy, chloroplast development, and plant growth, respectively. We generated a mutant with a single-codon deletion and two frameshift mutants of the ANT1 ortholog in the C4 millet Setaria viridis by the CRISPR/Cas9 technique. The two frameshift mutants displayed reduced photosynthesis efficiency and growth rate, smaller leaves, and lower grain yields than wild-type (WT) plants. Moreover, their leaves sporadically exhibited distorted Kranz anatomy and vein spacing. Conducting transcriptomic analysis of developing leaves in the WT and the three mutants we identified differentially expressed genes (DEGs) in the two frameshift mutant lines and found many down-regulated DEGs enriched in photosynthesis, heme, tetrapyrrole binding, and antioxidant activity. In addition, we predicted many target genes of ZmANT1 and chose 13 of them to confirm binding of ZmANT1 to their promoters. Based on the above observations, we proposed a model for ANT1 regulation of cell proliferation and leaf growth, vascular and vein development, chloroplast development, and photosynthesis through its target genes. Furthermore, our study revealed biological roles of ANT1 in several developmental processes beyond its known roles in plant growth and floral organogenesis.

59 BASIC BIOLOGICAL SCIENCES↗