The amount of protein produced per m2 by plants cultivated in soil in a greenhouse at three levels of fertilizer application, for c. 10 weeks, was estimated by Kjeldahl analysis of the TCA-insoluble fraction of freeze-dried material. The quantity of protein extractable for production of leaf protein concentrates was determined by Kjeldahl analysis of non-dried but frozen material after disintegration with a meat mincer and an Ultra-Turrax homogenizer, hydraulic pressing and filtration, and protein precipitation by heat (in two steps) or by TCA. The precipitability was also studied by Folin-Ciocalteu determination of protein. The quality of each protein concentrate was studied by determining nitrogen content (Kjeldahl), digestibility by pepsin and by pepsin+ pancreatin, nutritive value in Tetrahymena tests, and lysine and methionine content (analysed microbiologically).Twenty-nine species and varieties were investigated. Large differences between species were found in all the properties studied. Protein extractability varied between 5 and 80%, while the extractable protein produced per m2 ranged between I and 140 g. The highest digestibility was two to three times greater than the lowest one. In the most digestible species (Amaranthus caudatus), 82% of the N of the chloroplastic protein concentrate was digested by pepsin +pancreatin. The Tetrahymena value generally ranged between 40 and 98, whereas casein gave values of about 75. The lysine content always exceeded the FA0 minimum. The methionine content of most species varied between 2.0 and 2.2% of the hydrolyzed protein.Amaranthus caudatus and the Chenopodiaceae investigated were the most suitable species for large-scale production of leaf protein concentrates for human consumption because they gave high yield of extractable protein and high-quality protein concentrates.

No abstract

The aim of tlie present investigation was to separate und show the effect of j^rowtb-regulating substances in roots of wheat, and especially to find out if there are root growth-regulating substances with actions differing from that of auxin, particularly of tbe anti-auxin type.Material. Wbeat plants were grown in a nutrient solution at 22° C. The roots were harvested 10 to 12 days after germination and immediately extracted; 60 to 200 g. of roots (fresh weight) were used for each extract.Preparation of extracts: After washing the roots were crushed in a little ether and allowed to stand in ether for 48 hours at 5° C in the dark. About 500 ml. of peroxide-free ether were used per 100 g. of roots. Finally the roots were pressed and washed with several portions of ether in a IJiichner funnel. As it was found impo.ssible to carry out the following chromatograjjhy without a preliminary rough separation, only the acid fraction of the extracts was examined after preparation by repeated shaking with NaHCO;j-sohition (pH c. 8.5), acidifying this solution with HCl till pII 3 to 4, and shakiiig again wilh ether. Tbe etber was completely distilled off under reduced pressure in a nitrogen atmospbere. When further preparation was not immediately undertaken, in order to avoid oxidation as far as possible the residue was stored in tbe dark at 5' C in a nitrogen atmospbere until the following day, when it wa.s laken up in etbcr till a final volume of 1.5 ml.Method of separation. The different compounds contained in tbe extracts were separated by means of paper chroniatography, wbich was carried out at 22^ C on Munktell no. OB paper, with n-hutanol saturated with water and ammonia, as described by Luckwill (1), and with descending solvents.[406]

Three series of full-sib progenies and parental inbred lines or populations were used to study the inheritance of the number of cells and length of cell along the hypocotyl length, and the response to gibberellic acid in young plants of sugar beet. Variance components were determined by using a factorial cross design. There were no significant estimates of non-additive genetic variation for either cellular characters. Both additive and non-additive genetic variance were responsible for the variability of stem length after GA3 treatment. It is concluded that additive type genes predominantly control the number of cells in all series. The length of cell had significant additive variances in most cases, but it was indeed markedly influenced by environmental factors. Number of cells (cell division rate) and GA3 sensitivity in young plants even before vernalization were related to bolting tendency. Bolting-susceptible genotypes generally expressed higher stem length in the response to added GA3 as compared to the bolting-resistant genotypes. However, some genotypes bolted easily in the field but reacted weakly to the GA3 treatment and vise versa. Genotypes that were susceptible to bolting and/or sensitive to GA3 had a specific range (intermediate) of cell number. There were, however, some genotypes containing an intermediate number of cells which demonstrated low bolting. These responded faintly to gibberellin treatment. The results suggest that several physiological requirements have to be fulfilled before bolting can occur, and that other plant characters interfere with the bolting phenomenon.

The aim of the investigation was to correlate the sensitivity to Iow temperature that leads to bolting of sugar beet with a property of seedlings or seeds, analyzahle without cold treatment. Populations or inbred lines were investigated, tbe bolting percentages of which had been determined in field trials. Sulfhydryls (-SH) and disulfide sulphur (-S-) were analyzed by amperometric titration with silver nitrate. Disulfides were broken witb sulphite, and proteins were unfolded with urea.Negative correlations were found between the bolting percentage and (-SH + -S-) per leaf fresh or dry weight unit and per leaf protein nitrogen, with urea at the titrations. Positive correlations were obtained between the bolting percentage and the ratio of (-SH -t--S-) titratable in the absence of urea to that titratable in the presence of urea, when leaf homogenates or leaf or seed protein precipitates were examined. Centrifugation experiments showed that membrane proteins were responsible for the correlation. By poiyacrylamide gel electrophoresis of the membrane proteins it was found that the proportion between some of these proteins was correlated with tbe bolting percentage.From these results and such from analyses of beet plants during and after cold treatment a hypothesis was cotistnicted: Low bolting susceptibility, i.e., low sensitivity to low temperature, is caused by a high proportion of a hydropbobic membrane protein, rich in -SH or -S-. This protein interferes with the reactivity of the plants to gihberellins resulting from low temperatures or long days.