Different Levels Of Molybdenum Research Articles

Interactive Effects of Boron and Molybdenum on Nodulation, Growth and Yield of Cowpea under South Gujarat Condition

Background: Cowpea seeds are nutritious component of human diet and being a legume crop, it also improves the soil fertility by increasing the amount of nitrogen in the soil through symbiotic nitrogen fixation. To study the effect of boron and molybdenum on nodulation, growth and yield of cowpea the field experiment was conducted at the Regional Horticultural Research Station, Navsari Agricultural University, Navsari, Gujarat, India, during summer season of 2019 and 2021. Methods: The experiment was carried out in a factorial randomized block design with 3 replications. Factor-1 consisted of four levels of seed treatments with molybdenum at 2 mg/l (M1), 4 mg/l (M2), 6 mg/l (M3) for 24 hours prior to sowing including control (M0), where as the second factor was consisted of four levels of boron (B) spray at 2 mg/l (B1), 4 mg/l (B2), 6 mg/l (B3) and control at 30 DAS, 45 DAS and 60 DAS with control. Boron was applied in the form of Boric acid and Molybdenum as ammonium molybdate. Result: The treatment combination of seed treatment of molybdenum @ 2 mg/ l with foliar spray of boron @ 4 mg/ l at 30, 45 and 60 DAS (M1B2) has significantly influenced yield parameters and registered maximum number of clusters per plant (6.50), green pod yield per plant (0.153 kg), green pod yield per net plot (3.98 kg), green pod yield per hectare (12.27 tonne). Seed treatment with different levels of molybdenum has significantly influenced nodulation in cowpea and recorded maximum number of nodules per plant (31.69 at final harvest) and fresh nodule weight (0.230 g/plant) in seed treatment of molybdenum @ 2 mg/ l (M2) among all the treatments at final harvest during all the years of study, including pooled analysis.

Assessment of molybdenum application on soybean physiological characteristics in maize-soybean intercropping.

Soybean is a leguminous crop known for its efficient nitrogen utilization and ease of cultivation. However, its intercropping with maize may lead to severe reduction in its growth and yield due to shading effect of maize. This issue can be resolved by the appropriate application of essential plant nutrient such as molybdenum (Mo). Aim of this study was to assess the effect of Mo application on the morphological and physiological characteristics of soybean intercropped with maize. A two-year field experiment was conducted for this purpose, and Mo was applied in the form of sodium molybdate (Na2MoO4), and four different levels were maintained i.e., 0, 60, 120 and 180 g ha-1. Soybean exhibited varying responses to different levels of molybdenum (Mo) application. Notably, in both sole and intercropped cropping systems, the application of Mo at a rate of 120 g ha-1 demonstrated the highest level of promise compared to other application levels. However, most significant outcomes were pragmatic in soybean-maize intercropping, as application of Mo @ 120 g ha-1 significantly improved soybean growth and yield attributes, including leaf area index (LAI; 434 and 441%), total plant biomass (430 and 461%), transpiration rate (15 and 18%), stomatal conductance (9 and 11%), and yield (15 and 20%) during year 2020 and 2021 respectively, as compared to control treatment. Similarly, Mo @ 120 g ha-1 application resulted in highest total grain yield (626.0 and 725.3 kg ha-1) during 2020 and 2021 respectively, which exceeded the grain yields of other Mo levels under intercropping. Moreover, under Mo application level (120 g ha-1), grain NPK and Mo contents during years 2020 and 2021 were found to be 1.15, 0.22, 0.83 and 68.94 mg kg-1, and 1.27, 0.25, 0.90 and 72.18 mg kg-1 under intercropping system increased the value as compared to control treatment. Findings of current study highlighted the significance of Mo in enhancing soybean growth, yield, and nutrient uptake efficiency in maize-soybean intercropping systems.

Evaluation of the Efficacy of the Inoculum Prepared from the Two Local Isolates enterobacter colacae and enterobacter ludwigii on Soybean (glycine max l.) Growth and Yield in Gypsiferous Soil under Different Molybdenum Levels

With the aim of reducing chemical fertilizers and relying on environmentally friendly natural biofertilizers that promote plant growth and increase yield, especially in gypsiferous soils spread in arid and semi-arid regions, which suffer from physical, chemical, fertility, and biological problems, which in turn affect the density of microorganisms, This experiment was conducted to study the efficiency of the inoculum prepared from the bacteria E. cloacae and E. ludwigii isolated from gypsiferous soils and molecularly characterized in improving the growth and yield of soybeans under different levels of molybdenum in gypsiferous soil, possibly due to its absence, particularly the bacteria responsible for nitrogen fixation. The results showed that the two treatments inoculated with E. cloacae and E. ludiwgii were significantly superior to the uninoculated treatment in all studied growth and yield traits and the percentage of nitrogen and protein in the seeds, and that the treatment inoculated with E. cloacae bacteria was superior to the treatment inoculated with E. ludiwgii bacteria in all traits, as well as the treatment fertilized at the level of 2 kg Mo ha-1 was significantly superior to the non-fertilized in all traits and showed The results of the interaction between inoculation and fertilization with molybdenum showed that the E. cloacae + 2 kg Mo ha-1 treatment was superior to the comparison treatment in all traits and gave values of 278 pod plant-1, 127.66 g plant-1, 6.23 tons ha-1, 6.27%, and 39.13%. 0.36%, 0.071% for the number of pods, weight of pods, grain yield, concentrations of nitrogen, protein, and molybdenum in the seeds, and the concentration of molybdenum remaining in the soil after harvest, respectively, compared to the comparison treatment that gave the values 150.67 pod plant-1, 68.33 g plant-1, 3.43 tons ha-1, 5.42%, 33.83%, 0.33%, and 0.068 for the aforementioned characteristics, respectively.

Molybdenum fertilizer improved antioxidant capacity of Chinese Merino sheep under compound contamination.

To investigate the response of different levels of molybdenum (Mo) fertilizer to Chinese Merino sheep (Junken Type) grazing on natural heavy metal-contaminated meadows, this study was carried out in the Bayanbulak Grassland lying in the northwest of Xinjiang Uygur Autonomous Region, China. A total of 24-hm2 polluted meadows were fenced and were randomly divided into four groups (3 replication/group and 2 hm2/replication) applied 0-kg Mo, 1-kg Mo, 2-kg Mo, and 3-kg Mo (ammonium molybdate tetrahydrate) per hectare for the CON group, group I, group II, and group III, respectively. Seventy-two healthy 1-year-old Chinese Merino sheep (45.56 ± 2.35 kg) were randomly assigned to the tested pastures for 90 days. Compared with the CON group, the Mo content from fertilized groups and the Se content from group II and group III in serums and livers were significantly increased (P < 0.05), and the Cu content from fertilized groups in serums and livers was significantly decreased (P < 0.05). The levels of blood Hb and RBC, and the activities of serum SOD, CAT, GSH-Px, and Cp in group III, were significantly higher (P < 0.05) than those in the CON group, group I, and group II. Serum MDA content in group III was significantly lower (P < 0.05) than that in the other three groups. In summary, Mo fertilization improved the antioxidant capacity of grazing sheep and also reduced the toxic damage to Chinese Merino sheep grazing on natural grasslands contaminated by heavy metals, but Mo poisoning caused by excessive fertilization should be prevented.

Effect of Molybdenum and Bio-fertilizers on Growth and Yield of Cowpea (Vigna unguiculata L.)

A field experiment was conducted during Kharif, 2021 at crop research farm, Department of Agronomy, SHUATS, Prayagraj (U.P) with the objective to evaluate the influence of molybdenum and biofertilizers on growth and yield of cowpea. The soil texture of the experimental plot was sandy loam, nearly neutral in soil reaction having pH 7.1. The experiment was laid out in Randomized block design with ten treatments and were replicated thrice. The treatments comprising of different levels of molybdenum and bio-fertilizers i.e. Rhizobium and Phosphate solubilizing bacteria whose effect was observed in Cowpea. The treatment 6 with application of molybdenum 4g/kg seed and Rhizobium + PSB recorded significantly higher in plant height (78.64cm), branches/plant (15.07), nodules/plant (37.87) and dry weight (45.11g/plant). Molybdenum 4g/kg seed and Rhizobium + PSB also recorded significantly higher in yield and yield attributes viz. pods/plant (16.20), seeds/pod (12.80), seed yield (1.50t/ha), stover yield (4.17t/ha). Therefore, treatment with application of Molybdenum 4g/kg seed along with Rhizobium and PSB was more productive and can be recommended to farmers after further trails.

Effect of different levels of molybdenum and rhizobium phaseoli in rice-mung bean cropping system

Effect of different levels of molybdenum and rhizobium phaseoli in rice-mung bean cropping system

Effects of Different Levels of Molybdenum on Rumen Microbiota and Trace Elements Changes in Tissues from Goats.

Molybdenum (Mo) is an essential trace element for animals and human beings. However, the negative effects on rumen function and distribution of trace elements in tissues induced by excessive Mo have not been well understood. Therefore, the purpose of present study was to investigate the impact of Mo on rumen microbiota, distribution of trace elements in various organs, and hematological parameters of goats. A total of 36 goats were randomly distributed into three groups with equal number and low-Mo and high-Mo groups were orally administered ammonium molybdate at 15 and 45mg · Mo · kg-1 · BW respectively, while the control group received corresponding quantitative deionized water. The results showed that the total number of ciliate and protozoa protein concentration decreased significantly (P < 0.01) on days 25 and 50. Concentrations of ammonia nitrogen and bacterial protein were significantly higher (P < 0.05) in low-Mo group, while they were lower (P < 0.05) in high-Mo group than the control group on days 25 and 50. In addition, Mo accumulated in serum and all detected tissues. Copper (Cu) and zinc (Zn) contents significantly decreased (P < 0.05) in hair and serum on days 25 and 50, while Cu contents increased (P < 0.05) and the change of Zn contents were not obvious (P > 0.05) in other tissues on days 25 and 50. Besides, there was no obvious variation in iron (Fe) contents during whole experiment period (P > 0.05). Furthermore, excessive Mo content had no significant effect on red blood cell (RBC) counts and hemoglobin (HGB) concentration (P > 0.05) on days 25 and 50, while white blood cell (WBC) counts increased significantly (P < 0.05) on day 50. These results indicated that excessive Mo content could impact the balance of ruminal microorganisms and interfere with the absorption and distribution of Mo and Cu mainly.

Effect of Stress from Cadmium Combined with Different Levels of Molybdenum on Serum Free Radical and Expression of Related Apoptosis Genes in Goat Livers

Molybdenum (Mo) is an essential element for human beings and animals; however, high dietary intake of Mo can lead to adverse reactions. Cadmium (Cd) is one of the major transitional metals which have toxic effects in animals. The toxicity of simple Cd or Mo has been researched frequently. However, the toxicity of Mo combined with Cd was rarely studied. To investigate the toxicity of Mo combined with Cd in liver of goats, 36 Boer goats were randomly divided into four groups and assigned with one of the three oral treatments of CdCl2 (0.5mgkg(-1) Cd) and [(NH4)6Mo7O24·4H2O] (15mgkg(-1) Mo, group I; 30mgkg(-1) Mo, group II; 45mgkg(-1) Mo, group III), while the control group received deionized water. Blood samples were collected on days 0, 10, 20, 30, 40, and 50 to determine antioxidant indices in serum. In addition, liver tissues were collected on days 0, 25, and 50 for detecting the messenger RNA (mRNA) expression levels of Bcl-2 and Bax. Moreover, liver tissues at 50days were subjected to histopathological analysis with the optical microscope. The results revealed a significant increase (P<0.05 or P<0.01) in the levels of nitric oxide (NO), malonaldehyde (MDA), and the activity of nitrix oxide synthase (NOS) and a significant decline (P<0.05) in the activities of total superoxide dismutase (T-SOD) and total antioxidative capacity (T-AOC). The mRNA expression level of Bcl-2 was suppressed (P<0.05), while the expression of Bax was increased (P<0.05) in liver. The histopathological changes were observed in the liver of goats including a small amount of erythrocyte, the unclear structure of hepatic cord and hepatic sinusoid, granular degeneration, vacuolar degeneration, and steatosis. In conclusion, combined chronic toxicity of Cd with different levels of Mo might induce goat liver cell apoptosis and cause oxidative stress in serum, and it showed a possible synergistic relationship between the two elements.

Cell apoptosis of caprine spleen induced by toxicity of cadmium with different levels of molybdenum

In order to clarify the effects of the combination of Mo and Cd on goat and relationship between the two elements, combined chronic toxicity of cadmium with different levels of molybdenum in vivo on apoptosis gene and ultrastructure of spleen was evaluated with the methods of RT-qPCR and transmission electron microscopy. A total of thirty-six goats were randomly distributed in equal number into four groups. These groups were randomly assigned with one of three oral treatments of CdCl2 (0.5mgCd kg−1) and [(NH4)6Mo7O24·4H2O] (15mg Mo kg−1, group I; 30mg Mo kg−1, group II; 45mg Mo kg−1, group III), while the control group received deionized water. Spleen tissues were taken from individual goat at different time intervals to measure the levels of apoptosis genes including Bcl-2, Bax, Cyt c, Caspase-3, Smac and ceruloplasmin (Cp). The results revealed that a significant suppression in Bcl-2 expression and increase in Cyt c, Caspase-3 and Cp expression in splenic cells. The Bax expression in group I and II was up-regulated, however, it displayed reduction in group III, whereas no statistical significance was observed on Smac expression. In addition, histopathologic injury revealed remarkable morphplogical changes on the splenocytes in the means of apoptosis including fragmentized nucleus, apoptotic body and vesiculation of cytoplasma and mitochondria. Taken together, combined chronic toxicity of cadmium with different levels of molybdenum induce goat spleen cell apoptosis associated with mitochondrial intrinsic pathway, and the two elements showed possible antergic relationship.

Yield attributes and yield of fenugreek (Trigonella foenum graecum L.) under different levels of phosphorus, molybdenum and inoculation ofPSB

season, 2010-11 on loamy sand soil to investigate the effect of phosphorus (0, 20, 40 and 60 kg P 2 O 5 ha), molybdenum (0.0, 0.5 and 1.0 kg Mo ha) and PSB (without inoculation and with inoculation) on yield attributes, yield and seed quality of fenugreek (Trigonella foenum graecum L.). The application of phosphorus upto 40 kg P 2 O 5 ha resulted in significantly higher number of branches per plant, chlorophyll content at flowering stage, nodules per plant, pods per plant, seeds per pod, seed and straw yield over their respective preceding levels (0 and 20 P 2 O 5 ha) but it was found at par with 60 kg P 2 O 5 ha in respect to branches per plant, chlorophyll content at flowering stage, nodules per plant, pods per plant, seeds per pod, seed and straw yield of fenugreek. Among different levels of molybdenum, 0.5 kg Mo ha gave significantly higher branches per plant, chlorophyll content at flowering stage, nodules per plant, pods per plant, seeds per pod, seed and straw yield over respective lower level. PSB inoculation significantly enhanced the branches per plant, chlorophyll content at flowering stage, nodules per plant, pods per plant, seeds per pod, seed and straw yield of fenugreek. The test weight increased with the successive levels of applied phosphorus, molybdenum and PSB inoculation but difference could not reach the level of significance. The interaction effect of phosphorus × PSB was found significantly higher branches per plant, pod per plant and seed yield (1568 kg ha) recorded with treatment combination 40 kg P 2 O 5 ha + with inoculation of PSB which was at par with other treatment combination 60 kg P 2 O 5 ha + with inoculation of PSB.

Effects of Different Levels of Molybdenum on Uptake of Nutrients in Rice Cultivars

A hydroponic trial was carried out to determine the effect of molybdenum (Mo) on utilization and uptake of macro and micronutrients in different rice cultivars. The experiment was conducted using a randomized complete-block design, with a split-plot arrangement of treatments and three replications. Four rates of Mo (0, 0.01, 0.1 and 1 mg L-1) and five cultivars (MR219, HASHEMI, MR232, FAJRE and MR253) provided the main and sub-plots, respectively. The results showed that the enhancement of Mo levels (from 0.01 to 0.1 and 0.1 to 1mg L-1) led to increase of root Mo uptake by 81.7 and 61.6% and shoot Mo uptake by 43 and 87%, respectively. Also, Mo application significantly affected shoot Phosphorus uptake so that highest shoot Phosphorus (P) uptake (0.43% plant-1) was achieved at 1mg Mo L-1 but there was no significant influence on root P uptake. Shoot Iron (Fe) uptake was inversely proportional to increment of Mo rates therefore, the highest rate of shoot Fe (59.05 μg plant-1) was obtained in treatments with least amount of applied Mo. Also, increase in Mo application enhanced manganese (Mn) uptake of shoot but there was no significant effect on Mn root uptake.

The Effect of Molybdenum and Iron on Nodulation, Nitrogen Fixation and Yield of Chickpea Genotypes (Cicer Arietinum L)

The present study was based on the hypothesis that the applied molybdenum and iron influence the nodulation, nitrogen fixation and yield by chickpea genotypes. For this purpose a field experiment was conducted to study the influence of different levels of molybdenum and iron on the nodulation, nitrogen fixation and yield of chickpea genotypes (Cicer arietinum L.) growing two different genotypes such as Desi (sheenghar) and Kabuli (Karak-II) during, 2011-12 at Malakandher Farm, The University of Agriculture, Peshawar. Different levels of molybdenum and iron were applied at the rate of 0, 0.25 and 0.50 and 0, 2 and 5.0 kg ha -1 , respectively along with a basal dose of 25 N, 60 P2O5 and 60 K2O in randomized complete block design with split plot arrangement and replicated three times. Results revealed that maximum yield and yield parameters, numbers of root nodules and nitrogen concentration were observed in those treatment plots where Mo 0.5 and Fe 2.0 kg ha -1 were applied simultaneously for both genotypes. The grain yield, nodulation and nitrogen concentration were recorded significantly more in Kabuli (Karak-II) as compared to Desi (sheenghar) of chickpea genotypes, perhaps due to the formation of maximum nodulation and nitrogen concentration by plants. Results revealed that with increasing the levels of Mo and Fe in soil, the concentration of Fe and N in plant leaves were significantly increased in both genotypes at flowering stage. Moreover, in the present study the number of nodules were correlated with N concentration of plants for both genotypes and found as the nodules formation increases the plant N concentration linearly increased and showed close relationship with one another. Similarly, the Fe-concentration increases in plant leaves, N-concentration also increases in a similar fashion, indicated that Fe-played a vital role in N-fixation by chickpea genotypes. The present study suggests that the application of Mo 0.5 and Fe 2.0 kg ha -1 is important which play a significant role in getting the maximum yield, nodules and nitrogen concentration in chickpea genotypes.

Rapid hydroponic screening for molybdenum tolerance in rice through morphological and biochemical analysis

High yielding varieties of rice (Oryza sativa) cultivars were tested for their tolerance to different levels of molybdenum (Mo) (0.1&amp;micro;M &amp;ndash; control, 0.2, 0.4, 0.8 and 1.6&amp;micro;M) in nutrient solution at pH 6.8. Seeds of rice were germinated and grown in presence of molybdenum under controlled environmental conditions. Standard growth parameters such as root length, shoot length, root/shoot dry biomass and root/shoot tolerance index were tested as markers of molybdenum toxicity. Measurements as early as 48 hours after the germination did not yield consistent results. However, root measurement on 3&lt;sup&gt;rd&lt;/sup&gt;, 6&lt;sup&gt;th&lt;/sup&gt;&amp;nbsp;and 9&lt;sup&gt;th&lt;/sup&gt;&amp;nbsp;day after root emergence showed significant differences among cultivars of rice. Rice cultivars Annapurna, Kusuma, Deepa and Vaghari developed better root system while, Paridhan-1, Pusa-2-21 and Ratna showed poor growth of the roots in presence (0.8&amp;micro;M) of molybdenum. The root tolerance index (RTI) and the shoot tolerance index (STI) in Annapurna, Kusuma and Deepa in rice were high indicating their tolerance to molybdenum; Paridhan-1 and Ratna, however, showed low RTI and STI. Based on the growth parameters, twenty cultivars of rice were ranked in respect of their tolerance to molybdenum: Annapurrna &amp;gt; Deepa &amp;gt; Kusuma &amp;gt; Vaghari &amp;gt; Hamsa &amp;gt; Vikram &amp;gt; Bharati &amp;gt; Paridhan-2 &amp;gt; Aswathi &amp;gt; Subhadra &amp;gt; Sankar &amp;gt; Sakti &amp;gt; Nilgiri &amp;gt; Rudra &amp;gt; Hema &amp;gt; Pragati &amp;gt; Pusa-2-21 &amp;gt; Ratna &amp;gt; Paridhan-1, respectively. Molybdenum toxicity was correlated with increased peroxidase and catalase activity in different cultivars of rice. This method can be employed for quick screening of rice cultivars for molybdenum tolerance in breeding programmes.

EFFECT OF MODES AND LEVELS OF MOLYBDENUM APPLICATION ON GRAIN YIELD PROTEIN CONTENT AND NODULATION OF CHICKPEA GROWN ON LOAMY SAND SOIL

A field experiment was laid out during three consecutive years of 1997–98 to 1999–2000 on loamy sand soil (typic ustipsamment) of the state of Rajasthan in India in rabi season to investigate the effect of modes of application and different levels of molybdenum (Mo) on grain yield, protein content and number of nodules per plant of chickpea (Cicer arietinum L.; Variety RSG-44). Doses applied were: 0.5, 1.0 and 1.5 kg Mo ha−1 as ammonium molybdate for soil application, and 1.75, 3.5 and 5.25 g sodium molybdate kg−1 seed for seed treatment. The six treatments with one control were replicated thrice in a randomized block design. The physico-chemical characteristics of the soil were: pH-8.1, EC 0.11 dsm−1 and OC 0.12%. Available N, P and K were 158, 20 and 216 kg ha−1, respectively. The Mo status of soil was 0.06 ppm. The three years' pooled data revealed that application of Mo either by soil application or through seed treatment, significantly increased the grain yield of chickpea. Soil application of 1.0 kg Mo ha−1 and seed treatment with 3.5 g sodium molybdate kg−1 seed increased the grain yield by 13.13% and 16.76% over the yields (24.4 and 24.5 q ha−1, respectively) at lower doses while it was at par with yields at higher doses of Mo. Protein content of grain, number of nodules per plant of chickpea and available nitrogen in soil also increased with increasing doses of Mo under both the modes of application.

Activity of nitrate reductase and the content of proteins inNicotiana rusticagrown with various levels of molybdenum

Abstract The effect that different levels of molybdenum (11 μMand 111 μM) exert on nitrate reductase (E.C. 1.6.6.1–3) activity (NRA), and the content of total proteins in Nicotiana rustica was studied. Eleven μM and 111 μM of molybdenum increased the activity of nitrate reductase during the growth cycle of N. rustica. Likewise, total protein content (mg/g DW) was increased during the vegetative growth of the plants.

Interaction of phosphorus and molybdenum and the availability of zinc, copper, manganese, molybdenum and phosphorus in waterlogged rice soil

Laboratory incubation experiments were conducted with low-land rice soil to study the effect of applying three different levels of molybdenum (0, 2.5 and 5.0 ppm) and phosphorus (0, 100 and 200 ppm), in all possible combinations, on the changes in available Mo, P, Mn, Zn and Cu in soil. The results showed that application of Mo at both the levels increased the content of extractable Mo and P but decreased those of Cu and Mo in soil whereas application of Mo at higher level only increased the content of extractable Zn in soil. Application of P at both the levels decreased the content of extractable Mo, Mn and Cu but increased that of P whereas it showed an inconsistent effect on the extractable Zn content in soil. The P × Mo interaction effect was found to be beneficial for the content of P, Mo and Zn only. During the initial period of incubation all elements except Cu recorded an increase but with the progress of incubation period the content of all the elements except Mn gradually declined.

The use of copper levels in hair to diagnose hypocuprosis

The possibility of using hair to help diagnose hypocuprosis was investigated. Diets containing different levels of molybdenum and sulphur were fed to nine Hereford steers. Liver reserves of copper were depleted rapidly when dietary levels of molybdenum and sulphur exceeded 2.7 mg/kg and 3.8 g/kg respectively. Following the onset of diarrhoea, liver reserves of copper were repleted by injecting copper glycinate. Samples of liver, blood and hair were collected at regular intervals and analysed for copper. Progressive changes in liver levels of copper were closely paralleled by changes in copper levels in hair and plasma. Relationships between copper levels in liver and plasma, and the liver and hair were both shown to be asymptotic. Plasma and hair levels were sensitive to changes in liver reserves below about 20 microgram/g, but changed little above this level. Sampling variation was shown to be less with hair than with plasma. It was concluded that copper levels in hair are a useful diagnostic aid in detecting hypocuprosis. Hair provides an integrated record of copper availability during its period of growth, and thus may be preferred to blood plasma which represents only a spot sample in time.

Nutritional control of xanthine dehydrogenase. II. Effects on xanthine dehydrogenase and aldehyde oxidase of culturing wild-type and mutant Drosophila on different levels of molybdenum.

Two new mutants, deficient in aldehyde oxidase and xanthine dehydrogenase, have been isolated from a wild-type stock of Drosophila melanogaster and have been provisionally termed lxd-c and lxd-d, respectively, as both mutants appear to be allelic with lxd (low xanthine dehydrogenase). An analysis has been made of the effects of dietary molybdenum on lxd, lxd-c, lxd-d, lao (low aldehyde oxidase), mal (maroon-like eye color), and pac (Pacific) wild-type flies. On the lower dietary levels of 10(-3) M and 10(-2) M molybdenum, increases in specific activity of both enzymes were observed only in lxd. Furthermore, two- to three-fold increases in specific activity of both enzymes occurred in all strains, except mal, when cultured on 5 x 10(-2) M molybdenum. The lxd and lxd-c strains failed to survive on this high concentration of the ion. Similar concentrations of molybdenum had no effect in vitro. An extra electrophoretic band of xanthine dehydrogenase was observed on polyacrylamide gel from extracts of wild-type flies cultured on certain levels of molybdenum, but its appearance was not always correlated with the increases in specific activity.

Molybdenum as a Plant Nutrient: VIII The Effects of Different Molybdenum Levels and Nitrogen Supplies on the Nitrogen Fractions in Cauliflower Plants Grown in Sand Culture

PREVIOUS papers in this series described the effects of different levels of molybdenum on the growth and on the ascorbic acid, chlorophyll, molybdenum, sugar, nitrate and total nitrogen contents of cauliflower plants grown in sand cultures with two levels of nitrate (1, 2, 3). A later paper (4) presented the results of similar investigations, on the effects of different molybdenum levels given in the presence of different types of nitrogen supply. It was shown that the appearance of whiptail symptoms in molybdenum-deficient plants was independent of the form of nitrogen supply given. This paper presents results obtained for various nitrogen fractions, which, except for adenine, were determined in the same plants as those for which the results previously reported were obtained. Results of investigations on amino acid constituents by chromatography on filter paper are also given; they relate to plants grown in the experiments described previously and to plants grown on other occasions.