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Results for “Pisum sativum”

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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42 records · Page 3
All sourcesNASA NTRSDOE OSTI
NASA NTRS1984

Inhibition of polar calcium movement and gravitropism in roots treated with auxin-transport inhibitors

Primary roots of maize (Zea mays L.) and pea (Pisum sativum L.) exhibit strong positive gravitropism. In both species, gravistimulation induces polar movement of calcium across the root tip from the upper side to the lower side. Roots of onion (Allium cepa L.) are not responsive to gravity and gravistimulation induces little or no polar movement of calcium across the root tip. Treatment of maize or pea roots with inhibitors of auxin transport (morphactin, naphthylphthalamic acid, 2,3,5-triiodobenzoic acid) prevents both gravitropism and gravity-induced polar movement of calcium across the root tip. The results indicate that calcium movement and auxin movement are closely linked in roots and that gravity-induced redistribution of calcium across the root cap may play an important role in the development of gravitropic curvature.

Indoleacetic Acids/antagonists & inhibitors/metabo↗
NASA NTRS1984

Voltage transients elicited by sudden step-up of auxin

It is hypothesized (i) that the molecular mechanism for the reception of friction and flexure and the mechanism by which auxin enhances ethylene production have in common a release of free calcium into the cytosol, (ii) that elevated cytosolic calcium initiates vesicle exocytosis, and (iii) that the vesicles release a factor or set of factors which depolarizes the plasmalemma and promotes ethylene synthesis. One consequence of such exocytosis should be small, extracellularly observable voltage transients. Transients, ranging in size up to 600 microvolts and possessing risetimes (10-90%) of approximately 200 ms, are known to be elicited in etiolated stems of Pisum sativum L. by friction and are here shown to be elicited by sudden increase of auxin concentration and also by a Ca2+ ionophore.

Calcium/metabolism↗
NASA NTRS1992

Casein kinase II protein kinase is bound to lamina-matrix and phosphorylates lamin-like protein in isolated pea nuclei

A casein kinase II (CK II)-like protein kinase was identified and partially isolated from a purified envelope-matrix fraction of pea (Pisum sativum L.) nuclei. When [gamma-32P]ATP was directly added to the envelope-matrix preparation, the three most heavily labeled protein bands had molecular masses near 71, 48, and 46 kDa. Protein kinases were removed from the preparation by sequential extraction with Triton X-100, EGTA, 0.3 M NaCl, and a pH 10.5 buffer, but an active kinase still remained bound to the remaining lamina-matrix fraction after these treatments. This kinase had properties resembling CK II kinases previously characterized from animal and plant sources: it preferred casein as an artificial substrate, could use GTP as efficiently as ATP as the phosphoryl donor, was stimulated by spermine, was calcium independent, and had a catalytic subunit of 36 kDa. Some animal and plant CK II kinases have regulatory subunits near 29 kDa, and a lamina-matrix-bound protein of this molecular mass was recognized on immunoblot by anti-Drosophila CK II polyclonal antibodies. Also found associated with the envelope-matrix fraction of pea nuclei were p34cdc2-like and Ca(2+)-dependent protein kinases, but their properties could not account for the protein kinase activity bound to the lamina. The 71-kDa substrate of the CK II-like kinase was lamin A-like, both in its molecular mass and in its cross-reactivity with anti-intermediate filament antibodies. Lamin phosphorylation is considered a crucial early step in the entry of cells into mitosis, so lamina-bound CK II kinases may be important control points for cellular proliferation.

NASA Discipline Plant Biology↗
NASA NTRS2023

Legume Crop Testing for Space

Long-duration missions beyond low-Earth orbit will encounter challenges in maintaining adequate nutrition and crew acceptability in the food system. In situ production of fresh produce can supplement nutrient deficiencies in the prepackaged diet. Currently, there are a relatively small number of crops that can be reliably grown for space crop production efforts. Recent challenges with Veggie plant growth technical demonstrations, such as interveinal chlorosis and necrosis of Tokyo Bekana Chinese cabbage when grown under elevated CO 2 (~3000 ppm) and narrow-band LED lighting, have highlighted the necessity to conduct rigorous ISS-relevant crop screening on the ground. Additionally, crops should be selected to address specific nutritional deficits, as identified by NASA’s Human Research Program, with an emphasis on having a diversity of crops to meet nutritional requirements and crew acceptability. To achieve this, the concept of Crop Readiness Level (CRL) has been developed to gauge readiness of crops for spaceflight applications. CRL determination includes assessing environmental compatibility, food safety considerations, relevant nutritional analysis, and sensory analysis. Recent testing at Kennedy Space Center has focused on advancing the CRL of a variety of legumes. Twenty-four varieties of peas ( Pisum sativum ) and beans ( Phaseolus vulgaris ) were grown under 300 μmol m -2 s -1 PPFD from LED lights, 3000 ppm CO2, and 23 °C to simulate an ISS environment. Crops were harvested and size and yield were assessed. Then, baseline nutritional analysis (Vitamins B1, C, K; elemental analysis; proximate analysis) and sensory evaluation were performed on eight down-selected varieties. These baseline tests will help in selecting candidate crops for future missions and assessing crop production hardware and changes in environmental conditions on future crop performance and nutritional quality.

LaShelle E Spencer↗
DOE OSTI2024

Dirigent isoflavene-forming PsPTS2: 3D structure, stereochemical, and kinetic characterization comparison with pterocarpan-forming PsPTS1 homolog in pea

Pea (legume plant defense) phytoalexin pterocarpans (–)-maackiain and (+)-pisatin have opposite C6a and C11a configurations, but how this occurs biosynthetically is unknown. Herein, pea dirigent-protein (DP) PsPTS2, which generates 7,2'-dihydroxy-4',5'-methylenedioxyisoflav-3-ene (DMDIF), was investigated as regards stereoselectivity towards four possible 7,2'-dihydroxy-4',5'-methylenedioxyisoflavan-4-ol (DMDI) stereoisomers. Each DMDI stereoisomer configuration was determined using NMR spectroscopy, electronic circular dichroism, and molecular orbital analyses. PsPTS2 efficiently converted cis-(3R,4R)-DMDI into DMDIF, this being 20-fold faster than with the trans-(3R,4S)-isomer. The 4R-configured substrate’s near ß-axial OH orientation significantly enhanced its leaving group abilities in creating intermediate A-ring mono-quinone methide (QM), whereas the 4S-isomer’s 4-OH group α-equatorial orientation was a poorer leaving group. Substrate docking simulations also indicated that the 4R-configured ß-axial OH was closest to the Asp catalytic center, whereas the 4S-isomer’s α-equatorial OH was further away. Neither cis-(3S,4S)- nor trans-(3S, 4R)-DMDIs were substrates, even with the former having the same C3/C4 stereochemistry as (+)-pisatin. PsPTS2, assayed with cis-(3R,4R)-7,2'-dihydroxy-4'-methoxyisoflavan-4-ol [cis-(3R,4R)-DMI] and its C3/C4 stereoisomers, gave 2',7-dihydroxy-4'-methoxyisoflav-3-ene (DMIF), with the same substrate stereoselectivity. DP homologs may exist in licorice (Glycyrrhiza pallidiflora) and the tree legume Bolusanthus speciosus, as DMIF is found in both. PsPTS1 preferentially utilized cis-(3R,4R)-DMDI to give (–)-maackiain, this being 2200-fold more efficient than with cis-(3R,4R)-DMI. PsPTS1 also slowly converted trans-(3S,4R)-DMDI into (+)-maackiain, again reflecting the better 4R configured OH leaving group. Pea PsPTS2 and PsPTS1 provisionally provide a facile DP-engendered means to enable differing C6a and C11a configurations in (+)-pisatin and (–)-maackiain. Both DP transformations are considered to occur via DP-engendered generation of an identical mono-QM bound intermediate, which with PsPTS2 either re-aromatizes to give DMDIF or with PsPTS1 undergoes intramolecular cyclization to afford (–)-maackiain. Substrate docking simulations using PsPTS2 (2.5 Å resolution) and PsPTS1 (1.5 Å resolution) plausibly indicate that cis-(3R,4R)-DMDI binds in the anti-configuration in the PsPTS2 active site to afford DMDIF, and the syn-configuration in PsPTS1 to give maackiain.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2023

Exopolysaccharide is required for motility, stress tolerance, and plant colonization by the endophytic bacterium Paraburkholderia phytofirmans PsJN

Paraburkholderia phytofirmans PsJN is an endophytic bacterium and has been shown to promote the growth and health of many different plants. Exopolysaccharide (EPS) plays important roles in plant-bacteria interaction and tolerance to environmental stresses. However, the function of EPS in PsJN and its interaction with plants remain largely unknown. In this study, a deletion mutation of bceQ gene, encoding a putative flippase for the EPS biosynthesis, was introduced in the genome of PsJN. The ΔbceQ mutant produced a significantly lower level of EPS than the wild type strain in culture media. Compared to the wild type PsJN, the ΔbceQ mutant was more sensitive to desiccation, UV damage, salt (NaCl) and iron (FeCl 3 ) stresses, and bacteriophage infection. More importantly, the mutation of bceQ decreased the endophytic colonization of PsJN in camelina (Camelina sativa) and pea (Camelina sativa) under plant drought stress conditions. To the best of our knowledge, this is the first report that EPS production is required for the maximal colonization of an endophytic bacterium in the plant tissues under stress conditions.

59 BASIC BIOLOGICAL SCIENCES↗