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1.
Barley plants were grown hydroponically at two levels of K (3.0 and 30 mm) and Fe (1.0 and 10 μm) in the presence of excess Mn (25 μm) for 14 d in a phytotron. Plants grown under adequate K level (3.0 mm) were characterized by brown spots on old leaves, desiccation of old leaves, interveinal chlorosis on young leaves, browning of roots, and release of phytosiderophores (PS) from roots. These symptoms were more pronounced in the plants grown under suboptimal Fe level (1.0 p,M) than in the plants grown under adequate Fe level (10 μm). Plants grown in 10 μm Fe with additional K (30 mm) produced a larger amount of dry matter and released less PS than the plants grown under adequate K level (3.0 mm), and did not show leaf injury symptoms and root browning. On the other hand, the additional K supply in the presence of 1.0 μM Fe decreased the severity of brown spots, prevented leaf desiccation, and increased the leaf chlorophyll content, which was not sufficient for the regreening of chlorotic leaves. These results suggested that the additional K alleviated the symptoms of Mn toxicity depending on the Fe concentration in the nutrient solution. The concentration (per g dry matter) and accumulation (per plant) of Mn in shoots and roots of plants grown in 10 μm Fe and 30 mm K were much lower than those of the plants grown in 10 μm Fe and 3.0 mm K, indicating that additional K repressed the absorption of Mn. The concentration and accumulation of Fe in the shoots and roots of the plants grown in 10 μm Fe and 30 mm K were higher than those of the plants grown in 10 μm Fe and 3.0 mm K, indicating that the additional K increased the absorption of Fe under excess Mn level in the nutrient solution. The release of PS, chlorophyll content, and shoot Fe concentration were closely correlated.  相似文献   

2.
Nodule growth of a hypernodulating soybean (Glycine max (L.) Merr.) mutant line NOD1-3 was compared to that of its wild-type parent cv. Williams from 14 to 18 days after planting (DAP) in the absence of nitrate treatment (hereafter referred to as “0 mM treatment”) or with 5 mM nitrate treatment. The growth rate determined by increase in the diameter of the nodules was relatively lower in the mutant NOD1-3 than that of the parent Williams under nitrogen-free conditions (0 mM nitrate). The inhibition of nodule growth by 5 mM nitrate started at 1 d after the onset of the nitrate treatment in Williams, while the inhibition did not occur before the application of the nitrate treatment for 2 d in NOD1-3. The nodule growth was completely inhibited after 2 d in Williams and after 3 d in NOD1-3 during the 5 mM nitrate treatment period. After 4 d of 5 mM nitrate treatment, the nodule dry weight decreased by 22% in NOD1-3 and by 58% in Williams, respectively. The treatment with 5 mM nitrate decreased the acetylene reduction activity (ARA) in NOD1-3 by 60% per plant and by 50% per nodule g DW and these parameters were less sensitive to the treatment than those in Williams in which the inhibition rate was 90% per plant and 80% per nodule g DW. These results indicate that NOD1-3 is partially nitrate-tolerant in terms of individual nodule growth as well as total nodule dry weight and Nz fixation activity. A whole shoot of Williams and NOD1-3 plants was exposed to 14CO2 for 120 min followed by 0 or 5 mM nitrate treatment for 2 d, and the partitioning of the photoassimilates among the organs was analyzed. Under 0 mM nitrate treatment, the percentages of the distribution of 14C radioactivity between the nodules and roots were 63 and 37% in Williams and 89 and 11% in NOD1-3. Under the 5 mM nitrate conditions, the percentages of the distribution of 14C between the nodules and roots changed to 14 and 86% in Williams and 39 and 61% in NOD1-3, respectively. These results indicated that the hypernodulating mutant NOD1-3 supplied a larger amount of photoassimilates to the nodules than to the roots under nitrogen-free conditions, and that the nitrate depression of photoassimilate transport to the nodules was less sensitive than that of the parent line.  相似文献   

3.
The addition of exogenous proline (10 mm) to Na100-saline culture medium, modified LS medium (Linsmaier and Skoog 1965: Physiol. Plant., 18, 100–127) with 100 mm NaCl promoted the growth of tobacco (Nicotiana tabacum L., cv. Bright Yellow-2) suspension cells unadapted to salt stress without maintaining a high ratio of K+ to Na+ ions under salinity conditions. The addition of exogenous glutamic acid or alanine were not comparable to that of exogenous proline. The proline contents of the NaCl-unadapted cells became much higher when the cells were grown in Na100-saline culture medium with 10 mm proline than when the cells were cultured without proline. The accumulation of K+, Na+, counter ions was sufficient to compensate for the increase of the water potential of the cells caused by salinity. These results suggest that exogenous proline does not act as a nitrogen store and that proline may act as a protectant for enzymes and membranes against salt inactivation rather than as a compatible solute in tobacco suspension cells.  相似文献   

4.
It is well known that methyl mercaptan is porduced by the microbiological decomposition of methionine1),2),3). According to Kondo 4) and Onitake 1)not only hydrogen sulfide, but also methyl mercaptan were produced from cystine by E. coli and Proteus vulgaris in the medium containing one of glucose, lactose, sucrose, glycerin or histidine. Moreover, Onitake 1) found that methyl mercaptan was produced by the action of E. coli in the medium containing hydrogen sulfide and a trace of ethyl alcohol, and that evolution of methyl mercaptan began only 5 minutes after the start of experiment in the medium containing methionine, but it began after 12hrs in the medium containing 1-cystine and glucose. According to Birkinshaw, Findlay and Webb5) methyl mercaptan was found in the medium containing glucose, sulfate and other mineral salts, inoculated by Schizophyllum commune. In the same cultural condition as given above, methyl mercaptan, dimethyl sulfide, and dimethyl disulfide were detected by Challenger and Chartons 5) from the data presented above, in addition to microbiological formation of methyl mercaptan from methionine, the possibility cannot be excluded of methyl mercaptan formation by microbes from cystine, sulfate or hydrogen sulfide in the medium containing one of organic compounds such as sugars, glycerin, histidine and ethyl alcohol, etc.  相似文献   

5.
Abstract

The presence of 4-MeGln in the tulip plant was discovered by ZACHARIUS et al. (1954), and it was found that this amide generally occurred in the leaves of almost all the species of genus Tulipa (FOWDEN and STEWARD 1957a). The 4-MeGln compound has been detected in every part of the tulip plant, i.e., bulb scales, roots, basal plate, young shoots, leaves, stern, and flower (FOWDEN and STEWARD 1957a, b; OHYAMA 1986; OHYAMA et al. 1985, 1988a, b; ZACHARIUS et al. 1954, 1957). Especially 4-MeGln was found to be a major soluble N constituent in the leaves and stem of tulip of the flowering stage (OHYAMA et al. 1985; OHYAMA 1986).  相似文献   

6.
Recent studies have shown that the incorporation of ammonium nitrogen into amino acids in the leaves is strictly dependent on light (1-4). It is speculated that the effect of light on ammonium assimilation may be through the synthesis of the precursors of amino acids, or by the supply of the energy required for amination and amidation with organic acids. In the Vicia faba chloroplasts Givan et al. (1) exhibited that the synthesis of glutamic acid from a-ketoglutarate was linked with the generation of reduced pyridin nucleotide by photosynthetic electron transport. Mitchell and Stocking (2) suggested the direct coupling of glutamine formation with photophosphorylation in the pea chloroplasts. On the other hand. the processes of nitrate assimilation are more indebted to light than those of ammonium assimilation, because the former ones involve the reduction of nitrate to ammonium which is believed to be light-dependent (5). Canvin and Atkins (6). and Atkins and Canvin (7) reported that the incorporation of 15N-labeled ammonium and nitrate into amino acid fractiom was depressed by the dark treatment and by photosystem inhibitors; 3-(3′,4′-dichlrophenyl)-1-1-dimethylurea (DCMU) and carbonyl-cyanide-m-chlorophenyl-hydrazone(CCCP).  相似文献   

7.
A greenhouse experiment was conducted at Land Resources Research Institute, NARC, Islamabad to examine the impact of humic substances (HSs) coating on potassium fertilizers use efficiency. Tomato variety “Rio Grande” was used. The treatments applied were T1= Control (N, P at 250 and100?mg kg?1 respectively), T2?=?N, P?+?K at 200?mg kg?1 as SOP, T3?=?N, P?+?K at 200?mg kg?1 as NPK blend, T4?=?N, P?+?K at 200?mg kg?1 HSs coated SOP) and T5?=?N, P?+?K at 200?mg kg?1 HSs coated NPK blend. Results indicated a positive impact of sole and HSs coated products on agronomic traits, nutrient concentration, fruit quality traits, flower number, fruit umber, fruit weight, chlorophyll contents, fresh and dry biomass, tissue water contents, diameter and fruit mineral composition. The response of afore said traits to applied treatment varied.  相似文献   

8.
Nodulated soybean (Glycine max. (L) Merr. cv. Williams) plants were hydroponically cultured, and various combinations of 1-week culture with 5 or 0 mm nitrate were applied using 13-d-old soybean seedlings during three successive weeks. The treatments were designated as 0-0-0, 5-5-5, 5-5-0, 5-0-0, 5-0-5, 0-5-5, and 0-0-5, where the three sequential numbers denote the nitrate concentration (mm) applied in the first-second-third weeks. The size of the individual nodule was measured periodically using a slide caliper. All the plants were harvested after measurement of the acetylene reduction activity (ARA) at the end of the treatments. In the 0-0-0 treatment, the nodules grew continuously during the treatment period. Individual nodule growth was immediately suppressed after 5 mm nitrate supply. However, the nodule growth rapidly recovered by changing the 5 mm nitrate solution to a 0 mm nitrate solution in the 5-0-0 and 5-5-0 treatments. In the 5-0-5 treatment, nodule growth was completely inhibited in the first and the third weeks with 5 mm nitrate, but the nodule growth was enhanced in the second week with 0 mm nitrate. The nodule growth response to 5 mm nitrate was similar between small and large size nodules. After the 5-5-5, 5-0-5, 0-0-5, and 0-5-5 treatments, where the plants were cultured with 5 mm nitrate in the last third week, the ARA per plant was significantly lower compared with the 0-0-0 treatment. On the other hand, the ARA after the 5-0-0 and 5-5-0 treatments was relatively higher than that after the 0-0-0 treatment, possibly due to the higher photosynthate supply associated with the vigorous vegetative growth of the plants supplemented with nitrate nitrogen. It is concluded that both soybean nodule growth and N2 fixation activity sensitively responded to the external nitrate level, and that these parameters were reversibly regulated by the current status of nitrate in the culture solution, possibly through sensing of the nitrate concentration in roots and / or nodules.  相似文献   

9.
5-Aminolevulinic acid (ALA) acts to increase chlorophyll biosynthesis, photosynthesis, cold stress tolerance, and salt tolerance at low concentrations. We studied the effects of ALA on H2 15O translocation from the roots to the shoots of rice plants (Oryza sativa L. cv. Nipponbare) in real time by a positron-emitting tracer imaging system (PETIS). When the plant was treated with 10 μm ALA, the velocity of the H2 15O translocation from 2 to 12 min after absorption increased to 126, 137, 140% that of the control at 1.5, 2.5, and 3.5 h after ALA treatment, respectively. However, ALA did not affect the H2 15O translocation within 0.5 h of treatment. When the plant was treated with 0.1 mM ABA at 4 h after 10 μm ALA treatment, the velocity of the H2 15O translocation decreased at 0.5 h after ABA treatment. Those observations suggested ALA might be absorbed and transported to the guard cells within 1.5 h and functioned to expand the stomatal aperture.  相似文献   

10.
Most reports of the studies on solubilisatioh of phosphate in liquid culture and soil suggested that organic acids produced by microorganisms are responsible for promoting the dissolution of phosphate. Sperber (11, 12), Louw and Webley (7) and Duff, Webley and Scott (2) studied the production of acids by cultures of some phosphate dissolving fungi. actinomycetes and bacteria and observed that among the acids produced in liquid medium, hydroxy carboxylic acids such as lactic and 2-ketogluconic acids were responsible for solubilisation of phosphates. In the present studies, apart from the culture of Bacillus megaterium var. phosphaticum isolated from phosphobacterin which had been obtained from USSR. Indian strains of Bacillus megaterium, Bacillus circulans and Escherichia freundii isolated and identified by Sundara Rao and Sinha (13) were used. These studies were undertaken to find out different types of nonvolatile acids produced in Pikovskaya's (9) liquid medium.  相似文献   

11.
Nonexchangeable potassium (K-ne), i.e. 1 M NH4OAc-nonexchangeable K, often contributes significantly to plant nutrition. However conventional extraction methods often extract much more K-ne than plants even after intensive cropping, suggesting the difficulty in evaluating the amount of readily available soil K-ne. In this study, we used a milder extraction method (0.01 M HCl method) to examine its applicability to evaluate the amount of readily available K-ne in soil. In the first experiment, the concentration of K-ne in twenty surface soils sampled from agricultural fields in Japan and K-bearing minerals was determined by the 0.01 M HCl method, i.e. sequential extraction with 0.01 M HCl over a period of 10 d after removal of exchangeable K, and by conventional methods. The average percentage of the soil K-ne extracted by the 0.01 M HCl method amounted to 0.66% of the total K amount, and was much lower than that by a single extraction with 1 M HNO3 (2.0%) or with 0.2 M sodium tetraphenylboron for 2 d (22%). In the second experiment, the amount of K-ne removed by chemical extractions was compared with that of K-ne removed by maize plants grown for 29 d in five of the above soils. The amount of the K-ne evaluated by the 0.01 M HCl method gave the highest correlation (p < 0.05) with that of the K-ne utilized by plants among the extraction methods applied. The amount of soil K-ne extracted by the 0.01 M Hel method could therefore become a suitable index of the amount of readily available K-ne in soil. Extraction of K-ne in soils after maize planting further indicated that plants had removed K-ne more intensively than the 0.01 < HCl method probably only from the rhizosphere, although a high correlation was observed between the amount of K-ne removed by the 0.01 M Hel method and that by plants. This implies that the estimation of the amount of K-ne utilized by plants requires not only soil chemical analysis but also the evaluation of the percentage of the soil volume where the plant-induced release of K-ne actually occurs.  相似文献   

12.
Soil humus plays a significant role in the cation exchange of a soil. YOSHIDA (1) showed that, as a general rule, divalent ions such as calcium and magnesium were adsorbed more strongly onto humus than monovalent ions such as ammonium and potassium in an ion-exchange reaction. He did not, however, describe the behavior of heavy metal ions. BREMNER et al. (2) first suggested that soil organic matter forms complexes with polyvalent cations. HIMES and BARBER (3) found that soil organic matter reacts with divalent metal ions in a manner similar to the chelation reaction. Reviews of the soil organic matter-metal complex have been written by BREMNER et al. (2) and KAWAGUCHI, MATSUO and KYUMA (4).  相似文献   

13.
Abstract

Arsenic extractability with various solutions from peat samples collected in Deuli Village, Bangladesh, was investigated to reveal the leaching mechanisms of arsenic in sediments to groundwater. Peat layer was distributed at the depth of 7–8 m in the sediments, and the peat samples collected and used in this experiment contained 137 mg kg?1 arsenic. A wide range of pH values and concentrations of phosphoric acid and trisodium citrate was used for the extracting solutions. Arsenic extractability with Hel (25–1,000 mM) or NaOH (20–500 mM) at different pH values ranged for 30 to 60% in strong acid or alkali, while was less than 0.1% in the neutral pH range against the total content. Extraction of arsenic with 100 mM phosphoric acid and 100 mM trisodium citrate was about 20% even at a neutral pH, while the extractability with these solutions at concentrations below 1 mM was similar to that with distilled water. These results suggest that competitive exchange and / or chelating action are / is the prior possible mechanism for arsenic leaching from peat. However, the experimental conditions such as pH value or phosphate anion concentration differed from those in the study area where the pH of groundwater was almost neutral and the phosphate anion concentration was only 0.01 mM. Moreover, since the experiment was conducted using a batch system under oxidative conditions and not using a continuous flow system, the importance of the oxidation-reduction potential in the sediments and organic matter content in the groundwater should be investigated.  相似文献   

14.
We examined the effect of the calcium (Ca) concentration in the nutrient solution on the development of bacterial wilt and the population of its pathogen Ralstonia solanacearum in tomato (Lycopersicon esculentum Mill. cv. Momotarou) seedlings grafted onto the rootstock of a highly resistant cultivar (cv. Hawaii 7998). The grafted seedlings were cultured in a nutrient solution containing Ca at concentrations of 0.4, 4.4, and 20.4 mm, and inoculated with the pathogen by stem puncture at the base of the stem of the rootstock, and the disease incidence was recorded for a period of 21 d. In another experiment, xylem exudates were collected from decapitated scions of the Ca-treated seedlings 5 d after inoculation, and the population of the pathogen in the exudates was counted by plating on a selective medium. The grafted tomato seedlings were highly resistant to bacterial wilt, when cultured in the nutrient solution containing Ca at 20.4 mm. The population of the pathogen in the xylem exudates decreased with increasing concentration of Ca in the solution. However, even in the presence of Ca at a high concentration, infection with the virulent pathogen was observed in the xylem of the scion.  相似文献   

15.
Abstract

Several silicon (Si) extractants are being employed in different countries mostly for lowland acidic soils. Present investigation was conducted to evaluate suitable extractants for upland paddy grown on alkaline soils. Available Si was extracted by using ten different extractants. Tris buffer pH 7.0 (1:10) in Inceptisols showed positively highest and significant correlation with grain yield (r?=?0.870), grain Si uptake (r?=?0.887), straw yield (r?=?0.852), and straw Si uptake (r?=?0.919). However, 0.5?M acetic acid (1:2.5) in Vertisols showed positively highest and significant correlation with grain yield (r?=?0.810), grain Si uptake (r?=?0.852), straw yield (r?=?0.850), and straw Si uptake (r?=?0.929). The application of Si @ 200?kg ha?1 along with chemical fertilizers significantly increased yield and nutrient uptake of upland paddy on Vertisols. Tris buffer pH 7.0 (1:10) and 0.5?M acetic acid (1:2.5) were suitable extractant for Inceptisols and Vertisols, respectively based on its correlation with yield and nutrient uptake.  相似文献   

16.
Laminar opaline silica was first found in the 0.2 to 5 μ fraction and most abundant in the 0.4 to 2 μ fractions of young Japanese Andosols by Shoji and Masui (1969a, b). It was noted that the A horizon of a profile tends to be relatively rich in opaline silica whereas the B or C horizon, in allophane (Shoji and Masui, 1972a, b). They (I972a) distinguished four types of opaline silica particles such as circular, elliptical, rectangular, and rhombic, of which the circular and elliptical types predominate. It has been suggested that the formation of opaline silica is favored by a plentiful supply of soluble silica in the early weathering stage of Andosols, the supersaturation of silica by surface evaporation of soil solution, and the suppression of aluminum activity in the soil solution by the accumulation of soil organic matter (Shoji and Masui, 1972b; Wada and Harward, 1974). The purpose of the present short communication is to describe the occurrence of laminar opaline silica particles in some Oregon Andosols, U.S.A.  相似文献   

17.
Abstract

Studies on nutrient interactions in aromatic rice are needed for proper understanding of impact of imbalanced use of nutrients in the era of multi and micro-nutrient deficiencies. A pot experiment was conducted during the rainy/wet season (June–October) of 2013 at New Delhi, to study the interaction effects of two levels each of nitrogen (N) (0 and 120?kg?ha?1), phosphorus (P; 0 and 25.8?kg?ha?1), and zinc (Zn; 0 and 5?kg?ha?1) in two aromatic rice (Oryza sativa L.) varieties, viz. Pusa Rice Hybrid 10 and Pusa Basmati 1121. Application of N, P, and Zn resulted in increase of dry matter (0.91, 0.32, and 0.24?g plant?1, respectively) 60?days after sowing (DAS) and grain yield of rice (3.68, 1.67, and 1.17?g plant?1). The increase in yield of rice owing to N application was relatively higher by 0.98, 0.22, and 1.05?g plant?1, respectively, when either P or Zn or both were applied with N than alone application of N, indicating synergetic effect of P and Zn application with N. The higher concentration and uptake of K in grain (0.25% vs 0.10%) and straw (1.32% vs 0.94%) were observed in the treatment received N than no N, though K was applied uniformly in all the treatments. It indicates positive interaction of N and K. The higher uptake of P in grain and straw was observed when P was applied with N and Zn (3.34 and 2.15?mg plant?1), or with N (3.26 and 2.11?mg plant?1) signifying positive effect of N on P uptake in rice.  相似文献   

18.
Kursanov et al. conducted a series of studies on the CO2 uptake by roots and translocation and uilization in plant, using carbon-l4 labelled CO2. Kursanov, Kuzin and Mamul1) first studied the uptake of CO2 by the roots of intact bean seedlings and found that after 18-hours exposure in the light, most of the radioactive carbon was translocated upwards. Later on, in a more detailed paper2) these Russian workers estimated that under their experimental conditions, the amount of CO2 absorbed by roots is as much as 25 per cent of that taken up from the atmosphere by leaves. They also reported that soluble carbonates supplied as a fertilizer increased the yield of bean, barley, potato and sugar beet by 15 to 18 per cene). In addition Grinfeld 4) stated that 30–50 kg of CO2 per hectare, dressed as ammonium carbonate, increased the yield of sugar beet by 7 to 16 per cent.  相似文献   

19.
There have been several papers dealing with the difference in chemical composition between callus tissue and normal parent tissue. WEINSTEIN, TULECKE, NICKELL, and LAURENCOT (1–3) revealed, in a series of papers, that the contents of amino acids, sugars, and nucleic acids often differed strikingly between callus and normal tissue of Agave toumeyana Trel. (1), Ginkgo biloba, L. (2), and PAUL's scarlet rose (3). STEWARD, THOMPSON, and POLLARD (4) also reported that the content of some amino acids of rapidly growing and randomly proliferating tissue is outstandingly different from that of normal tissue.  相似文献   

20.
We isolated a novel Arabidopsis thaliana mutant line that requires high levels of boron (B) for normal growth. Line 8–21 was identified from ethyl methanesulfonate-mutagenized M2 population. When grown in medium containing 3 μm or less B in the form of boric acid, the fresh weights of aerial portions of the mutant were about a half of those of the wild type, but in that containing 300 μm B, the growth appeared normal. The mutant plants did not shown any difference in root growth from the wild-type plants in the range of B concentrations tested. When grown with 30 μm B, the B concentration in shoots of the line 8–21 was similar to that in the wild-type, suggesting that the mutant could not utilize B efficiently. Line 8–21 was not allelic to bor1-1 (Noguchi et al., Plant Physiol., 115, 901–906, 1997). A significant portion of F2 plants from the crosses between the wild-type and the mutant grew poorly on a low B media, suggesting segregation of the mutation.  相似文献   

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