Importance of molybdenum in the nitrogen metabolism of microorganisms and higher plants

Mulder, E. G.

doi:10.1007/bf02080608

Cited by 122 publications

(41 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, since the comparisons were made between healthy and deficient plants, the possibility that the differences observed were due to the different physiological age of the plants could not be excluded. Mulder (1948) avoided this complication by comparing deficient plants with those which had been treated with molybdate only 3 days prior to harvest, and produced evidence which confirmed the conclusions of Hewitt, Jones, and Williams (1949).…”

Section: Introducitonmentioning

confidence: 88%

“…Although it has been known for some time that molybdenum is essential for the utilization of nitrate by plants (Steinberg 1937;Hewitt and Jones 1947;Mulder 1948) no satisfactory evidence has been presented to indicate the precise step in this process for which molybdenum is required. Hewitt, Jones, and Williams (1949) showed that not only protein but also amino acid content in molybdenum-deficient plants was low in comparison with that of normal plants, and concluded that molybdenum was required for some step between the initial reduction of nitrate and the formation of amino acids.…”

Section: Introducitonmentioning

confidence: 99%

See 1 more Smart Citation

The Role of Molybdenum in Nitrate Reduction Inhigher Plants

Spencer¹,

Wood²

1954

Aust. Jnl. Of Bio. Sci.

View full text Add to dashboard Cite

SummaryExperiments are described which were designed to locate the molybdenumrequiring step in the chain of reactions involved in nitrate utilization in higher plants.Tomato plants deficient in molybdenum were treated with molybdate, and the changes in content of nitrate, nitrite, ammonia, amides, amino acids, and proteins, expressed on a dry weight basis, were followed over a short period. Two days after treatment with molybdate there was a marked decrease in the level of nitrate. During this period the concentrations of nitrite, ammonia, amides, amino acids, and protein increased. The nitrite and ammonia contents of the tops were doubled 4 hr after supplying molybdate to the molybdenumdeficient plants.It is concluded that in the intact plant molybdenum is essential for a reaction involved in the reduction of nitrate to nitrite. The known metabolic functions of molybdenum are discussed briefly.Analytical methods used in these determinations are described.

show abstract

Section: Introducitonmentioning

confidence: 88%

Section: Introducitonmentioning

confidence: 99%

The Role of Molybdenum in Nitrate Reduction Inhigher Plants

Spencer¹,

Wood²

1954

Aust. Jnl. Of Bio. Sci.

View full text Add to dashboard Cite

show abstract

“…Total N was determined by the Kjeldahl method modified to include nitrates. Nitrate N was determined by the method described by SNEiLiL and SNEILL (12).…”

mentioning

confidence: 99%

Molybdenum Nutrition of Alfalfa

1950

View full text Add to dashboard Cite

Molybdenum is the latest element to be found essential for microorganisms and higher plants. The literature, recently reviewed by MULDER (12), indicates that Mo is necessary for N fixation by Azotobacter and Rhizobium and for the metabolism of nitrates by all plants. The biological importance of Mo was originally discovered by BORTELS (3, 4), who reported that Azotobacter and peas, soybeans, and red clover showed increases in growth and in N fixation from additions of Mo. Essentiality of Mo for higher plants was first demonstrated by Arnon and Stout in 1939. Using highly purified nutrient solutions, they produced Mo-deficiency symptoms in tomatoes in six successive experiments. Later JENSEN and BETTY (9) and JENSEN (10) reported that small applications of Mo to alfalfa and clover growing in pots of sand increased the yields of tops and the N content of both tops and roots. Mulder showed that nodulated peas grown in culture solutions lacking both Mo and combined N quickly developed Ndeficiency symptoms. The Mo requirement of tomatoes was greatly reduced when ammonium N was substituted for nitrate N in the nutrient solutions. Recent work by HEWITT and JONES (8) indicates that Mo is indispensable for the growth of tomatoes, cauliflower, cabbage, and mustard and that it functions in the reduction of nitrates. VANSELOW and DATTA (15), using the spectrographic method, studied the Mo requirements of lemons and found that leaves containing 0.01 p.p.m. Mo were deficient but those containing concentrations greater than 0.024 p.p.m. were normal. Deficiency was produced with either nitrate or ammonia N.Further investigation of the importance of Mo in plant nutrition has been stimulated by reports of Mo-deficient soils in AUSTRALIA (1, 2),

show abstract

“…A requirement for Mo is known for the reductive systems of Neurospora, soya bean and probably Escherichia coli, where it is also thought to act as an electron carrier: the relevant literature has been reviewed by Nason (Biochemists' Handbook, 1961b). Other biological uses of Mo are known: it affects the nitrogen metabolism (Mulder, 1948) and the growth (Mulder, 1954) of some higher plants and micro-organisms ; molybdate is metabolized by Azotobacter (Keeler, 1958) and by certain farm animals (Stewart, Farmer & Mitchell, 1946). The concentration of molybdenum (m,uM) required by Azotobacter (Burk, 1934) are not as small as with the present Leptothrix and vanadium can replace molybdenum (Horner, Burk, Allison & Sherman, 1942) in the case of Azotobacter more easily.…”

Section: Discussionmentioning

confidence: 99%