The Respiration of Barley Plants

Folkes, B. F.; Willis, A. J.; Yemm, E. W.

doi:10.1111/j.1469-8137.1952.tb06140.x

Cited by 46 publications

(28 citation statements)

References 15 publications

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“…Usually about three-quarters of the loss front the endosperm was recovered as embryo nitrogen. This picture is sufficiently similar to well documented results obtained with barley (10,11) centrations of the neutral amino acids in the excised By contrast, much smaller increases in nitrogen were embryo were less than the initial levels. The drop observed in the excised embryos.…”

Section: Resultssupporting

confidence: 76%

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The Requirement for Organic Nitrogen in Zea mays Embryos

Oaks

Beevers

1964

Plant Physiol.

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Previous investigations have shown that, during germination, there is a transfer of organic nitrogen from storage tissues to the developing embryo (16). Indeed in both barley (10) and pea (5) specific storage proteins are the first components to disappear. (7), and which have been grown to maturity (1), present an apparent exception to the general picture. However, Nason (18) has shown that excised maize embryos have abnormally low levels of trypotophan, and when our own preliminary investigation showed that the amount of protein in such embryos was drastically reduced, an investigation was made of the importance of organic nitrogen normally supplied by the endosperm. A progress report of this work has appeared previously (20). MethodsMaize grain (hybrid variety Wf 9 X 38-11) was sterilized briefly with chlorox, rinsed, and allowed to germinate on a thin layer of agar (1.5%) in the dark at 260. When the root was 2 cm long (about 40 hr) the embryos (including scutella) were removed by sterile excision. Three or four normal seedlings (intact) or excised embryos were transferred to 10 ml of a mineral-salts solution (14,18) for soluble nitrogen and a-amino nitrogen determinations. The amino acids were washed free of other components in the alcohol extract by passage through a 6 X 1-cm column of Dowex-50 X 8 (H+) cation exchange resin and eluted with iN NH4OH. They were further fractionated into acidic, neutral, and basic amino acids by the procedures of Hirs, Moore and Stein (13,17). In this procedure glutamic and aspartic acids were adsorbed on a 20 X 1-cm Dowex-1 X 10 (acetate) column. Glutamine and asparagine in the water effluent from this column were hydrolyzed in iN HCl for 4 hours at 1000. The resulting glutamic and aspartic acids were adsorbed on a second Dowex 1-X 10 (acetate) column. The water effluent from this column was passed through a 15 X 1 cm Dowex-50 X 98 (Na +) column to adsorb the neutral and basic amino acids. The neutral amino acids were eluted with 15 nml of 0.1 mr Na citrate (pH 5.0) and the basic amino acids, including y-amino butyric acid, with 0.5 m Na citrate (pH 7.5). Glutanlic and aspartic acids were eluted serially from the Dowex-1 X 10 (acetate) columns with 0.2 N acetic acid. After each step in the procedure the eluates were dried and the a-amino nitrogen of each fraction was determined with ninhydrin (24). ResultsTransfer of Nitrogen front the Endosperm to tihe Embryo. Results with intact maize seedlings (fig 1) showed that during germination the alcohol-insoluble nitrogen fraction increased in the embryo while it declined in the endosperm. The level of alcoholsoluble nitrogen increased temporarily in the endosperm and had not fallen below the initial level at 96 hours. There was a progressive increase in this fraction in the embryo after 20 hours. Usually about three-quarters of the loss front the endosperm was recovered as embryo nitrogen. This picture is sufficiently similar to well documented results obtained with barley (10, 11) to assume that organic nitrogen is transferre...

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Section: Resultssupporting

confidence: 76%

“…In the zein (2). There is also an efficient transfer of amillo acids derived from endosperm protein to protein inI the growing parts in barley (10,11 (4 ). There is a concomitant rise in glutamic and asl)artic acids and their amides, but a striking clecrease in the soluble pools of the more complicated amino acids.…”

Section: Resultsmentioning

confidence: 97%

The Requirement for Organic Nitrogen in Zea mays Embryos

Oaks

Beevers

1964

Plant Physiol.

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“…In some of his experiments ammonium nitrogen seemed to stimulate the rate of respiration to a greater extent than nitrate, although the latter also had an appreciable effect. WILLIS (1951)" FOLKES, WILLIS andYEMM (1952), andWILLIS andYEMM (1955) consistently observed that in nitrogen-starved barley seedling roots the application of ammonium or nitrate salts produced a considerable stimulation of the respiration rate. From the graphs presented by WILLIS and YEMM (1955) it appeared, moreover, that the respiratory increase due to ammonium salt addition was faster than the increase due to nitrate addition.…”

Section: Starvation and Respirationmentioning

confidence: 90%

On the Mechanism of Ammonium Ion Uptake by Maize Roots

Becking

1956

Acta Botanica Neerlandica

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“…At 7 days, significant growth of leaf blades is complete (7); respiration reaches a peak (5,8,20); and nucleotides, protein nitrogen (13). and soluble protein (Fig.…”

Section: Resultsmentioning

confidence: 99%

Influence of Age and Illumination on Distribution of Several Calvin Cycle Enzymes in Greening Barley Leaves

Obendorf¹,

Huffaker²

1970

Plant Physiol.

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Activities of phosphoriboisomerase, phosphoribulokinase, and ribulose 1,5-diphosphate carboxylase, protein content, and chlorophyll accumulation in dark-grown barley seedlings were measured before and after illumination. Enzymatic activities, levels of soluble protein, and accumulation (upon illumination) of chlorophyll in leaves declined from tips toward the base. In response to increasing time of illumination, chlorophyll accumulation and activities of phosphoribulokinase and ribulose 1 ,5-diphosphate carboxylase (enzymes located in chloroplasts) increased most in tip portions whereas activity of phosphoriboisomerase and levels of soluble protein (constituents not confined to chloroplasts) increased similarly in all sections of the leaf. Maximum activity of phosphoribulokinase and maximum accumulation of chlorophyll shifted toward median portions of the leaf blade with increased age of seedling before illumination. Maximum activity of ribulose 1 ,5-diphosphate carboxylase and maximum level of soluble protein occurred in all leaf sections when the seedlings were 7 days of age before illumination.Upon the illumination of dark-grown seedlings, chlorophyll accumulates, protein is synthesized, chloroplasts develop an ordered lamellar form, the activity of photosynthetic enzymes increases, and net incorporation of CO2 begins. Some information is available on the development of several of these and other components with position in the leaf and age of the leaf. Rhodes and Yemm (13) reported that chloroplasts were larger and developed faster in the older cells of barley leaf tips than in younger cells at the base. Protochlorophyll levels in etiolated barley leaves declined from the tip toward the base (17). A decline in the tip with increasing age, however, shifted the maximal concentration toward the median sections. Williams and Rijven (19) noted marked differences in the timing of maximum protein and RNA levels for different parts of developing wheat leaves. Information is lacking on the development of photosynthetic enzymes in relation to position in the leaf and the development of other constituents. This paper reports the influence of illumination and leaf age and section on the activities of phosphoriboisomerase, phosphoribulokinase, and ribulose-1,5-diP carboxylase, and on soluble protein and chlorophyll.'Present address:

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The Respiration of Barley Plants

Cited by 46 publications

References 15 publications

The Requirement for Organic Nitrogen in Zea mays Embryos

The Requirement for Organic Nitrogen in Zea mays Embryos

On the Mechanism of Ammonium Ion Uptake by Maize Roots

Influence of Age and Illumination on Distribution of Several Calvin Cycle Enzymes in Greening Barley Leaves

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