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1.
Changes in activity levels of important enzymes of carbohydratemetabolism (and ß-amylases, sucrose synthetase, acidinvertase, acid phosphatase, glucose phosphate isomerase, aldolase,phosphofructokinase and pyruvate kinase) during seed developmentwere determined. Changes in the activities of these enzymesand their functional significance in developing seeds are described.A close correlation was found between the stage of maximum carbohydrateoxidation and the accumulation of reserve materials in the developingseeds.
1Present address: School of Agriculture and Forestry, Universityof Melbourne, Parkvilie 3052, Victoria, Australia.
2Present address: School of Botany, University of Melbourne,Parkville 3052, Victoria, Australia. (Received October 8, 1982; Accepted January 10, 1983) 相似文献
2.
Summary Gibberellins A3, A4+7 and A13 and (–)-kaurene delay floral-bud initiation and flowering and decrease the number of floral-buds and flowers in Impatiens balsamina under 4-hr photoperiods. They do not have any marked effect under 8-hr photoperiods. Under 16- and 24-hr photoperiods they hasten floral-bud initiation and flowering and increase the number of flowers, the effect being greater under 16- than under 24-hr days and the order of effectiveness being GA4+7>GA3>GA13>(–)-kaurene.While GA3 and GA4+7 promote extension growth, the effect being greater with the former, GA13 and (–)-kaurene do not promote it under any photoperiod. The magnitude of stem elongation in different treatments prior to floral-bud initiation increases from 4- to 8-hr photoperiods but decreases under 16- and 24-hr periods, the effect being more under 24-hr although both 16-and 24-hr photoperiods are noninductive for flowering. 相似文献
3.
Rice seedlings accumulate stainable amounts of the 104 and 90 kDa polypeptides in response to high temperature stress. We have purified and raised highly specific polyclonal antisera against both of these polypeptides. In western blotting experiments, we find that these proteins are accumulated to different extents in rice seedlings subjected to salinity (NaCl), water stress, low-temperature stress and exogenous abscisic acid application. These proteins also accumulated when rice seedlings grown in pots under natural conditions were subjected to water stress by withholding watering. Seedlings of Triticum aestivum, Sorghum bicolor, Pisum sativum, Zea mays, Brassica juncea and mycelium of Neurospora crassa showed accumulation of the immunological homologues of both the 104 and the 90 kDa polypeptides, in response to high-temperature stress. We have earlier shown that shoots of rice seedlings exposed to heat shock accumulate a 110 kDa polypeptide which is an immunological homologue of the yeast HSP 104 (Singla and Grover, Plant Mol Biol 22: 1177–1180, 1993). Employing anti-rice HSP 104 antibodies and anti-yeast HSP 104 antibodies together, we provide evidence that rice HSP 104 is different from the earlier characterized rice HSP 110. 相似文献
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A composting experiment was conducted to evaluate the effect of a hyperlignocellulolytic fungal consortium and different nitrogen
amendments on paddy straw composting in terms of changes in physicochemical and biological parameters. A fungal consortium
comprising four lignocellulolytic mesophilic fungal cultures was used as inoculum for bioaugmentation of paddy straw in perforated
pits. The comparative effect of farmyard manure (FYM), soybean trash, poultry litter and urea on the composting process was
evaluated at monthly intervals in terms of physicochemical (pH, EC, available P, C:N ratio and humus content) and biological
(enzymatic and microbial activity) parameters. The compost prepared from bioaugmented paddy straw composting mixture, with
poultry manure as nitrogen supplement attained desirable C:N ratio in 1 month and displayed least phytotoxicity levels along
with higher production of β-1,4-Exoglucanase. The combined activity of the autochthonous composting microbiota as well as the externally applied fungal
inoculum accelerated the composting process of paddy straw. Supplementation of paddy straw with poultry manure in 8:1 ratio
was identified as the best treatment to hasten the composting process. This study highlights the importance of application
of fungal inoculum and an appropriate N-amendment such as poultry manure for preparation of compost using a substrate having
high C:N ratio, such as paddy straw. 相似文献
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Deepti Singh Priyanka Gupta Sneh Lata Singla-Pareek Kadambot H.M. Siddique Ashwani Pareek 《Current Genomics》2021,22(1):59
BackgroundThe two-component signaling (TCS) system is an important signal transduction machinery in prokaryotes and eukaryotes, excluding animals, that uses a protein phosphorylation mechanism for signal transmission.ConclusionProkaryotes have a primitive type of TCS machinery, which mainly comprises a membrane-bound sensory histidine kinase (HK) and its cognate cytoplasmic response regulator (RR). Hence, it is sometimes referred to as two-step phosphorelay (TSP). Eukaryotes have more sophisticated signaling machinery, with an extra component - a histidine-containing phosphotransfer (HPT) protein that shuttles between HK and RR to communicate signal baggage. As a result, the TSP has evolved from a two-step phosphorelay (His–Asp) in simple prokaryotes to a multi-step phosphorelay (MSP) cascade (His–Asp–His–Asp) in complex eukaryotic organisms, such as plants, to mediate the signaling network. This molecular evolution is also reflected in the form of considerable structural modifications in the domain architecture of the individual components of the TCS system. In this review, we present TCS system''s evolutionary journey from the primitive TSP to advanced MSP type across the genera. This information will be highly useful in designing the future strategies of crop improvement based on the individual members of the TCS machinery. 相似文献
9.
In the present study, we used osteoprotegerin (OPG), which blocks osteoclastogenesis, to correct and thus explain the hypercalcemia that is seen during dietary Mg deficiency in the mouse. Control and Mg-deficient mice received injections for 12 days of either OPG or vehicle only. Serum Ca was similar in Mg-deficient mice treated with OPG and in control mice receiving OPG (9.2±0.3 mg/dl vs. 9.2±0.5). Both groups had significantly higher serum Ca than controls or Mg-deficient animals receiving vehicle alone. Surprisingly, Mg-depleted mice that received OPG in doses that inhibit osteoclastic bone resorption remained hypercalcemic. Because mature osteoclasts still present in the marrow might be hyperactive, we examined osteoclast morphology at the light microscopic and ultrastructural level. Light microscopic examination of trabecular bone showed few osteoclasts in OPG-treated mice. Ultrastructural examination revealed that osteoclasts in OPG-treated mice have decreased contact with the endosteal bone surface and absence of a ruffled border. Because the morphology of the existing pool of mature osteoclasts did not enhance resorption, another mechanism, such as increased intestinal absorption of Ca in Mg-deficient mice, likely contributes to the hypercalcemia observed during Mg deficiency. 相似文献
10.
A nickel hexacyanoferrate polypyrrole film was synthesized through an electrochemical two-step methodology leading to a very stable and homogenous robust hybrid film. A highly sensitive, specific and rapid amperometric d-amino acid biosensor was constructed by immobilizing d-amino acid oxidase on this film deposited over the surface of a glassy carbon electrode. The modified electrode was characterized by scanning electron microscopy, electrochemical impedance spectroscopy and Fourier transform infrared spectrophotometry. The biosensor showed optimum response within 1 s, when operated at 50 mV s?1 in 0.01 M Tris HCl buffer, pH 7.0 at 30 °C. The biosensor exhibited excellent sensitivity with a detection limit of 1.5 µM (S/N = 3) for d-amino acids and wider linear range, 20–500 µM. Analytical recovery of added d-alanine (5 and 10 mM) in serum samples was 98.00 and 98.80 %, respectively. Within-batch and between-batch coefficients of variation in serum samples were 1.36 and 2.77 %, respectively. The enzyme electrode was used more than 50 times over 2 months, when stored at 4 °C. The proposed modified electrode exhibited sufficient mechanical and electrochemical stability and high sensitivity compared to earlier electrochemical d-amino acid biosensors. Interference by ascorbic acid and uric acid, the main interfering species in the biological samples, was negligible. 相似文献