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A cDNA encoding a putative H+-translocating pyrophosphatase (H+-PPase) has been cloned from Zea mays by suppression subtractive hybridization (SSH) coupled with in silico cloning approach. The isolated 2974 bp full-length cDNA named ZmGPP contains a single 2400 bp open reading frame encoding a
Tonoplast-enriched vesicles isolated from maize (Zea mays L.) coleoptiles and seeds synthesize ATP from ADP and inorganic phosphate (Pi) and inorganic pyrophosphate from Pi. The synthesis is consistent with reversal of the catalytic cycle of the H+-ATPase and H+-pyrophosphatase (PPase) vacuolar
Low phosphate availability is a major constraint on plant growth and agricultural productivity. Engineering a crop with enhanced low phosphate tolerance by transgenic technique could be one way of alleviating agricultural losses due to phosphate deficiency. In this study, we reported that transgenic
Plasma-membrane-located primary pumps were investigated in the sieve element (SE)-companion cell complex in the transport phloem of 2-week-old stems of Ricinus communis L. and, for comparison, in stems of Cucurbita pepo L. and in the secondary phloem of Agrobacterium tumefaciens-induced crown galls
The present study was undertaken to determine whether vacuolar H(+)-pyrophosphatase (V-PPase) might replace vacuolar H(+)-ATPase under energy stress due to anoxia or chilling in anoxia-tolerant species such as rice (Oryza sativa L.) and corn (Zea mays L.). The relative transcript level of V-PPase in
There have been conflicting reports in the literature concerning the polypeptide composition of the vacuolar H(+)-translocating inorganic pyrophosphatase (tonoplast H(+)-PPase) of plant cells. The major subunit(s) of the enzyme have been attributed to polypeptides of relative molecular weight (M(r))
BACKGROUND
Cyperus rotundus L. is a C4 weed of large vegetative and reproductive vigor endowed with competitive advantages over most crop species mainly under adverse environmental conditions. Vacuole functions are critical for the mechanisms of drought resistance, and here the modulation of the
Preparations enriched in plastids were used to investigate the location of ADP-glucose pyrophosphorylase (AGPase) in the developing endosperm of maize (Zea mays L.). These preparations contained more than 25% of the total activity of the plastid marker enzymes alkaline pyrophosphatase and soluble
The phosphohydrolase activity of a light microsomal fraction isolated from corn roots (Zea mays L. cv LG 55) was investigated. The fraction, which appears to be enriched in endoplasmic reticulum and Golgi membranes, has ATPase and pyrophosphatase activities that hydrolyze ATP and pyrophosphate at an
Corn (Zea mays L. cv Trojan T929) coleoptile membranes were fractionated on isopycnic sucrose density gradients. Two peaks of ATP-driven H(+)-transport activity, corresponding to the previously characterized tonoplast (1.07 grams per cubic centimeter) and Golgi (1.13 grams per cubic centimeter)
The energy derived from pyrophosphate (PPi) hydrolysis is used to pump protons across the tonoplast membrane, thus forming a proton gradient. In a plant's cytosol, the concentration of PPi varies between 10 and 800 microm, and the PPi concentration needed for one-half maximal activity of the maize
Tonoplast vesicles were isolated by discontinuous sucrose gradient centrifugation in the presence of Mg(2+) from 5 day old corn (Zea mays L., Golden Cross Bantam) seedling roots. Marker enzyme assays indicated only a low degree of cross-contamination of tonoplast vesicles at the 10/23%
Comparative analysis of the transport activity of proton pumps (plasmalemma H+-ATPase, vacuolar H+-ATPase, and vacuolar H+-pyrophosphatase) in the membrane preparations obtained from coleoptile cells ofetiolated maize seedlings (Zea mays L.) was carried out. The highest level ofvacuolar
ATP-sulfurylase (ATP-sulfate adenyltransferase, EC 2.7.7.4) was found in nonparticulate fractions of both roots and leaves of Zea mays L. seedlings using two detection methods. Addition of exogenous pyrophosphatase was essential for maximum rates of conversion of (35)SO(4) (2-) to labeled adenosine
To gain a better understanding of the mechanisms that underpin aortic calcification, rodent models have been previously utilised. Regions of calcium and phosphate deposition are commonly visualised using labor-intensive two-dimensional histomorphometric techniques. In this study, we developed a