Pea Test Research Articles

On Cyanine Dyes. XI. The Relative Activities of Cyanine Dyes and related Cycloammonium Salts in the Pea Test

On Cyanine Dyes. XI. The Relative Activities of Cyanine Dyes and related Cycloammonium Salts in the Pea Test

The detection and determination of auxins in organic manures. Part II.—Extraction of auxins from manures, and applications of the perchloric acid test for β-indolyl acetic acid and of the went pea test

The detection and determination of auxins in organic manures. Part II.—Extraction of auxins from manures, and applications of the perchloric acid test for β-indolyl acetic acid and of the went pea test

Untersuchungen über Pflanzliche Wuchsstoffe. VII. Über Struktur und Wirkungsmechanismus der Pflanzlichen Wuchs‐ und Hemmstoffe

The view of the mechanism of the action of plant growth substances developed elsewhere has led to the assumption that growth substances and inhibitors in plants may be closely related1). The results of some recent investigations10) 11), which in our opinion support this view, are discussed, and in the case of cis‐cinnamic acid coumarin (lactone of o‐oxy(cis)cinnamic acid) such a structurally related pair of growth substance and inhibitor is indicated.In the pea test, inhibitor (coumarin) and growth substance (naphthalene acetic acid) prove to be antagonists, while such an influence cannot be established in the blastokolin test. A number of compounds with the structure of inhibitors (unsaturated lactones) are examined in the blastokolin test. Furthermore the importance of these investigations for the natural auxins is outlined. The formation of unsaturated δ‐lactones, being possible in that case, does really occur in the photo‐inactivation of auxin‐a‐lactone (conversion into lumi‐auxone). On account of this the hypothesis is developed that lumi‐auxone (or a closely related compound) may perform the function of an inhibitor.Finally a number of facts from botanical investigations are summarized, which point to the close relationship between growth substance and inhibitor and which, moreover, support the view of the function of lumi‐auxone (or related compound)

On the Nastic and Traumatic Responses in the Pea Test

American Journal of BotanyVolume 29, Issue 3 p. 201-206 Article ON THE NASTIC AND TRAUMATIC RESPONSES IN THE PEA TEST Charles L. Schneider, Charles L. Schneider Stanford University, CaliforniaSearch for more papers by this author Charles L. Schneider, Charles L. Schneider Stanford University, CaliforniaSearch for more papers by this author First published: 01 March 1942 https://doi.org/10.1002/j.1537-2197.1942.tb13993.xCitations: 2AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Citing Literature Volume29, Issue3March 1942Pages 201-206 RelatedInformation

ON THE NASTIC AND TRAUMATIC RESPONSES IN THE PEA TEST

THE PEA TEST of Went (1934), a test method for the plant growth hormone auxin, depends on the curvature of longitudinally slit, growing stems (see sketch, fig. 1). Because of released tissue tensions and compressions, the slit halves of the stems curve strongly outward, a new equilibrium position being reached after a short time. In auxin solutions the preliminary outward curvature is soon followed by an inward curvature, i.e., a curvature toward the cut surface. This inward curvature is a result of unequal growth of the inside and outside layers of tissue and is a function of the auxin concentration. There has been a series of investigations on the physiological mechanism of this response (Went, 1934; Jost and Reiss, 1936; van Overbeek and Went, 1937; Tbimann and Schneider, 1938, 1939; Jost, 1938; Went, 1939). The explanations offered cover most of the conceivable possibilities and include: 1. Growth of the layers of cells near the longitudinallv cut surface such that these inner cells become more nearlv isodiametric; i.e., they decrease in length although they increase in volume. Thus the inside becomes shorter and causes an inward curvature. 2. Auxin can enter only through the intact surface (not through the cut surface), and establishes, therefore, an auxin gradient such that the 'outer layers are stimulated to grow more than the inner. 3. All layers have about equal access to the supplied auxin, but the central and peripheral layers inherently accumulate auxins to different degrees or respond to them to different degrees-i.e., the response is nastic. 4. The injury resulting from slitting reduces the potential growth of cells near the cut-i.e., the response is traumatic. The first two explanations have already been abandoned. The nastic and traumatic explanations remain; their evaluation in relation to each other is the subject of this paper. In making this evaluation, allowances must be made for the variable condition of the material used. For example, the finding that a given fraction of the curvature of highly responsive halved stems is the result of trauma or of nasty need not necessarily hold exactly in another case where only slightly responsive halved stems are encountered. In this connection it is of interest that with pea stems the reactivity varies to such a degree as to give the large curvatures reported by Went (1934, 1939) or no inward curvatures at all as reported by Jost and Reiss (1936); similarly with dandelion (Taraxacum) flower stalks, either inward pea test curvatures or only extreme outward curvatures can be obtained, in this case, de-

DEPENDENCE OF THE AVENA COLEOPTILE GROWTH‐RATE ON THE PREVIOUS AUXIN SUPPLY

DEPENDENCE OF THE AVENA COLEOPTILE GROWTH‐RATE ON THE PREVIOUS AUXIN SUPPLY

Comparison of Growth Responses Induced in Plants by Naphthalene Acetamide and Naphthalene Acetic Acid

1. A comparison was made of some of the responses of certain plants when treated with naphthalene acetamide and naphthalene acetic acid. 2. Naphthalene acetamide caused growth curvatures when used in the pea test, and in Avena coleoptiles when applied unilaterally in the form of a 0.02 per cent lanolin mixture. When applied to coleoptiles in relatively low concentrations (250 gamma per liter), using the usual Avena test with agar blocks, the acetamide failed to give growth curvatures. Naphthalene acetic acid caused growth curvatures in both the pea and Avena test at concentrations of 1 mg. per liter and 250 gamma per liter, respectively. 3. Unilateral applications of lanolin containing naphthalene acetamide (2 per cent) on stems of etiolated pea and kidney bean plants resulted in negative curvatures. No apparent curvatures resulted when the stems of four o'clock, soybean, and tomato plants grown in natural light were treated unilaterally with acetamide. Petunia and kidney bean plants treated in this manner showed slight negative curvatures. Applications of a 2 per cent mixture of lanolin and naphthalene acetic acid resulted in first negative then positive bending in all except kidney bean plants grown in light. Negative curvatures were interpreted as resulting from initially low concentrations of the acid. Growth was apparently inhibited, on the side of the stem nearest the application, as the concentration of acid in the tissues became greater. 4. Naphthalene acetamide and naphthalene acetic acid were applied to bean plants in the form of emulsion sprays. Both compounds inhibited development of the terminal buds and expansion of primary leaves when used in strong concentration. The acetamide stimulated root growth over that of untreated plants while the acid was ineffective in this respect. The less concentrated acetamide sprays accelerated top growth to some extent while the acid sprays had no noticeable effect. 5. Terminal applications of 2 per cent lanolin-naphthalene acetamide or naphthalene acetic acid mixture to decapitated beans or lateral applications on the stems resulted in mobilization of solid materials toward the treated region. Mobilization was associated with appreciable secondary thickening in plants treated with naphthalene acetamide, and with marked cellular proliferation when naphthalene acetic acid was applied.

Further Analysis of the Pea Test for Auxin

Further Analysis of the Pea Test for Auxin

Relation of Environment and of the Physical Properties of Synthetic Growth Substances to the Growth Reaction

1. It is concluded that the acid curvature in the pea test is due to a greater growth of the cut surface than of the intact surface. This is explained as due to a higher concentration of active auxin on the cut surface, caused by a measurable decrease of the internal pH of the cut surface, when split pea sections are placed in acid buffers. 2. A correlation is found between the dissociation curves and the activities at different internal pHs of cis-cinnamic acid and phenylacetic acid. 3. By correcting for difference in pK, so that only equimolar concentrations of the free acid are compared, it is found that cis-cinnamic acid possesses the same activity as indole (3) acetic acid in the pea test. The activity of phenylacetic acid, although enhanced, was not so high as that of indole (3) acetic acid. 4. By pretreating pea sections with phenylbutyric acid and correcting for difference in pK when possible, the following compounds are found to possess molar activities equal to that of indole (3) acetic acid in ...

Mechanism and Quantitative Application of the Pea Test

1. If growing stems of pea seedlings are split and immersed in a solution containing auxin, the two halves will curve inward (fig. 5). This pea test curvature is proportional to the logarithm of the auxin concentration (fig. 6). The curvature is due to differential growth. 2. The epidermis side of the halved stems grows faster than the wounded inside (fig. 1). This difference in growth in turn is caused by the fact that auxin is unable to enter the stem through the wounded surface. If auxin is forced into the halved stems by infiltration with auxin solutions, the inside will grow just as much as the unwounded epidermis side (table 6). 3. The pea test can be successfully used for quantitative auxin determinations, the technique of which is described. 4. The pea test curvature is dependent upon the pH of the auxin solutions (fig. 6). At greater acidities greater curvatures are obtained. As in the Avena coleoptile, the sensitivity of the pea stems to auxin has a daily and seasonal variation. A wide variety o...

Auxin, the plant growth-hormone

I. This continuation of the review on auxin in volume 1 of this journal is necessarily incomplete, for more than 500 papers have appeared on the subject in the last ten years, and space does not permit a more extended treatment. Only a few trends in the field will be enumerated, and whenever a number of papers on the subject have appeared in close sequence, usually only one or a few of them are listed, the choice being more or less arbitrary; availability of them in America, and sometimes priority or completeness in their exposition, have been used as criteria for selection. More stress is laid in this supplement on the theoretically important points than on the practical ones, since another review in this journal by Zimmerman on growth hormones has been announced; Zimmerman is one of the chief exponents of less theoretical treatment of the plant hormone field (38). Detailed information can be found elsewhere (8, 9, 31, 49, 56, 74, 84, 89), and the same subdivision will be followed here as in the original review, although the emphasis on subjects has shifted very much. II. The Avena method is still the principal method of quantitative analysis of auxins. A modification of it (61), the deseeded Avena test, is more sensitive to low concentrations and has been accepted as the standard test in some laboratories. Other qualitative and semiquantitative tests have been described in great number. Only the "green tissue tests" (38) and the pea test (76, 80) need be mentioned. Also, new auxin units have been introduced, W.A.E. of Boysen Jensen (9) and T.D.C. of Avery et al. (2), but they have exactly the same disadvantage as the A.E. of Kogl. They all depend on the relative sensitivity of Avena coleoptiles to auxin, which sensitivity varies with time of day, season, locality and laboratory. The only more or less absolute unit, although not ideal, is van Overbeek's (53) indoleacetic acid equivalent. It gives the amount of indoleacetic acid inducing the same curvature in the Avena test as the tested sample. III. Chemical isolation and identification nf indlneaetic acirl 1 Supplement to article in The Botanical Review 1: 162-182. 1935. 487