Endogenous Plant Growth Substances Research Articles

Simultaneous analysis of endogenous plant growth substances during floral sex differentiation in Jatropha curcas L. using HPLC–ESI–MS/MS

Abstract The seed of Jatropha curcas is an ideal feedstock for producing biodiesel. However, low seed yield which was limited by its low female to male flower ratios is a bottleneck for its utilization. Here, six endogenous plant growth substances, Indole-3-acetic acid (IAA), Gibberellin A3 (GA3), Zeatin (Zt), Abscisic acid (ABA), Jasmonic acid (JA), and Salicylic acid (SA), were evaluated in male and female floral differentiation stages to uncover the regulatory events of endogenous plant hormones in J. curcas. Our results showed that the female floral initiation was accelerated by the higher concentration of Zt, GA3, JA, SA and the ratios of JA/GA3%, JA/Zt%, and GA3/Zt%, whereas its subsequent development was involved in low concentration of Zt and GA3. Conversely, the lower concentration of Zt, GA3, JA, SA and the ratios of GA3/SA%, Zt/SA%, and JA/SA% were significantly related to male floral initiation, and its subsequent development was co-promoted by the higher concentration of IAA, Zt, GA3 and JA. In addition, the concentration of ABA was down-regulated both in male and female floral differentiation processes. To our knowledge, this is the first investigation to link floral sex differentiation with endogenous plant growth substances in J. curcas. It provided insight into the potential for the regulation of flowering and the increase of fruit yield with exogenous plant growth substances.

Applications of magnesium affect pericarp colour in the Feizixiao lychee

ABSTRACTThe pericarp of the Feizixiao lychee (Lychee chinensis Sonn.) remains green when the concentration of sugar in the aril peaks, the so-called stay-green phenomenon. The objective of the present study was to evaluate the effect of foliar-applied Mg on pericarp colour, and to determine the relationship between pericarp colour, plant growth substances, and activities of the key enzymes associated with colour development. We quantified the pigment concentrations and endogenous plant growth substances (abscisic acid – ABA – and ethylene), and determined the activities of chlorophyllase (Chlase), pheophorbide acid monooxygenase (PaO), and UDP-glucose:flavonoid 3-O-glucosyltransferase (UFGT). Magnesium was found to increase the accumulation of anthocyanin in the pericarp, and contributed to the red colour of the pericarp and overcame the stay-green phenomenon. In contrast, Mg had no effect on the concentration of chlorophyll in the pericarp. Strong relationships between anthocyanin, UFGT, and ABA suggest that the enzyme increased the accumulation of anthocyanin by increasing the concentration of ABA and the activity of UFGT. Strong negative relationships between chlorophyll, PaO and Chlase, and ethylene production suggest that ethylene increased the degradation of chlorophyll by increasing the activity of the two enzymes. The Mg spray was suggested for application in lychee orchards.

Light Mediates Endogenous Plant Growth Substances in Thidiazuron-induced Somatic Embryogenesis in Geranium Hypocotyl Cultures

Thidiazuron-induced somatic embryogenesis in geranium (Pelargonium x hortorum Bailey) was readily achieved under both light and darkness. The hypocotyl explants treated with TDZ formed well differentiated embryos when incubated under conditions of continuous light, complete darkness or 16-h photoperiod. However, embryogenesis was significantly impaired by light at both 16-h and continuous light exposure. Maintaining the cultures in the dark increased the frequency of the somatic embryos formed with a corresponding moderate elevation of the endogenous plant growth substances measured. In the complete absence of TDZ, all of the hypocotyl explants cultured in the dark remained thin but formed etiolated roots. The number of explants that formed roots decreased with increasing light exposure time; in addition the roots formed were shorter in length. The levels of endogenous adenine, adenosine, DHZ, zeatin, isopentenyladenine (2iP), tryptamine, IAA and ABA remained elevated for the first 2 days of culture in explants maintained on MSO and under continuous light, while they decreased on day 3 of culture. We provide evidence that the interaction between TDZ and light treatments modulated the endogenous plant growth substances, which in turn affected the embryogenic process in geranium hypocotyl explants.

The aromatic cytokinins

After the discovery of kinetin (Miller et al. 1956, J. Am. Chem. Soc. 78: 1345–1350) there was a flurry of syntheses that led to the finding of 6‐benzylaminopurine (BA), an active and easily obtainable cytokinin. Much research into cytokinin physiology was subsequently done with this substance. Further, the isolation and unequivocal identification of natural BA and the high biological activity of its meta‐hydroxylated analogues stimulated the search for other natural aromatic cytokinins. Screening was accomplished by ELISA of HPLC fractions using antisera against ortho‐ and meta‐hydroxybenzyladenosine. Subsequent isolation and decisive identification by mass spectrometry led to discovery of a broad spectrum of endogenous plant growth substances structurally similar to a highly active compound, meta‐topolin (6‐[3‐hydroxybenzyl‐amino]purine), and to its less active analogue, ortho‐topolin (6‐[2‐hydroxybenzyl‐amino]purine). The structures of such aromatic cytokinins suggest considerably different biosynthetic pathways from that of zeatin and related isoprenoid cytokinins. From a physiological viewpoint, aromatic cytokinin metabolism can be classified under four main headings analogous to isoprenoid cytokinins: interconversion, hydroxylation, conjugation, and oxidative degradation. This review attempts to put into context what is known about 9‐alkyl‐BAs and compares their metabolism in regard to the practical use of cytokinins in agriculture and biotechnology. The recently discovered unusual specificity of additionally C2,N9‐disubstituted aromatic cytokinins toward cell cycle kinases, suggests that these cytokinin‐derived growth regulators may selectively inhibit certain steps of the cell cycle. The functional overlap of the aromatic cytokinins with those of their isoprenoid counterparts and cytokinin inhibitors, in relation to growth and developmental processes in plants, has yet to be determined.

ブドウ‘巨峰’の結実と小花中の内生植物ホルモンとの関係

The effects of dipping flower clusters before bloom in solutions of various plant growth regulators (GR) on the setting of parthenocarpic and seeded berries in 'Kyoho' grape were studied. The effects of a) dipping immature rachis in 2, 500 ppm succinic acid-2, 2-dimethyl hydrazide (SADH) and b) severe winter pruning on the content of endogenous plant growth substances in florets were also examined. The 'Kyoho' vines were trained to a vertical espalier and the pergola trellis systems.1. Dipping flower clusters in plant growth retardants, ((2-chloro-ethyl) trimethyl ammonium chloride) (CCC) and SADH significantly increased the set of seeded berries as compared to the control clusters. Among different dosages of GR, 2, 500 ppm SADH was most effective, independent of the training system; applications of growth promoters were ineffective in setting seeded berries. SADH also increased the number of seeds per berry, especially on vines trained to an espalier system.2. Severe pruning resulted in a high percentage set of seedless berries.3. An application of SADH decreased gibberellin (GA) and increased abscisic acid (ABA) contents in florets. Contrarily, severe pruning resulted in a rapid increase in GA level at bloom and a decrease in ABA content. The amount of cytokinins and indole-3-acetic acid (IAA) in florets also changed with these treatments. The amount of cytokinins increased with SADH treatment, but the relationship between the setting of seeded berries and the level of cytokinins and IAA in florets could not be established.These results suggest that poor berry setting in 'Kyoho' can not be explained by the theory of nutritional competition between cluster development and shoot growth. That endogenous plant growth substances, especially GA and ABA, in the florets are closely associated with the setting of seeded berries became evident in this study.

Study of endogenous plant growth substances in Douglas fir II. Gibberellin analysis

Study of endogenous plant growth substances in Douglas fir II. Gibberellin analysis

Study of endogenous plant growth substances in Douglas fir I. Cytokinin analysis

Study of endogenous plant growth substances in Douglas fir I. Cytokinin analysis

Endogenous Plant Growth Substances in Developing Fruit of Prunus cerasus XIII. Relationship between Conjugated and Free Abscisic Acid in Pericarp

Abstract The presence of abscisic acid (ABA) in both conjugated and free forms was established by thin-layer and gas-liquid chromatography and by combined gas chromatography-mass spectrometry. The concentration of the free acid was greater than that of conjugated ABA early in fruit development (Stages I and II); however, the conjugated form was more prevalent than the free acid during Stage III. The highest concentration of both the free acid and the conjugated ABA was found during periods of most active fruit enlargement and low concentrations during the retarded phase of pericarp growth. The conjugated form represented a significant and, during Stage III, the major portion of the total ABA present.

Endogenous plant growth substances content in young fruits of seeded and seedless Clementine mandarin as related to fruit set and development

The content of plant growth substances in the fruits of seedless (‘Fino’) and seeded (‘Monreal’) Clementine mandarin ( Citrus reticulata Blanco) during the early stages of development was investigated. Auxin-like substances were determined with the oat mesocotyl bioassay, gibberellin-like substances with the α-amylase bioassay, and abscisic acid (ABA) by gas chromatography—electron capture detector. Methanolic extracts of fruits of seedless Clementine had higher content of auxin-like compounds in the acidic and butanolic fractions than the seeded Clementine extracts. In particular, a compound with R f 0–0.25 in the chromatograms may be involved in the parthenocarpic fruit set development of ‘Fino’ Clementine ovaries. Diffusable gibberellin-like compounds ( R f 0.8–1.0), probably produced in the developing seeds, were obtained from seeded Clementine fruits after the time of anthesis. The content of ABA in the fruits was always low in ‘Monreal’ Clementine, whereas in fruits of ‘Fino’ Clementine and of ‘Monreal’ without seeds it increased dramatically after anthesis. It is suggested that the control of fruit set and development in Clementine mandarin is carried out through an equilibrium between auxin-like substances (‘Fino’) or gibberellin-like substances (‘Monreal’) and ABA.

REVIEWS

Books reviwed in this article: Handbook of Phycological Methods – Developmental and Cytological Methods. Ed. by Elisabeth Gantt Endogenous Plant Growth Substances. By Thomas A. Hill Plants and Islands. Ed. by D. Bramwell Forest Ecology. By Stephen H. Spurr and Burton V. Barnes Biochemistry and Physiology of Plant Hormones. By T. C. Moore Bryophyte Systematics. Ed. by G. C. S. Clarke and J. G. Duckett Spät‐ und postglaziale Waldgeschichte der Alpen auf grund der bisherigan Pollen‐analysen. By F. Kral Nature and Origins of Carbohydrates in Soils. By M. V. Cheshire Morphology and Infrageneric Relationships of the Getius Jatropha (Euphorbiaceae). University of California Publications in Botany, Volume 74. By Bijan Dehgan and Grandy L. Webster Amenity Grassland: An Ecological Perspective. Ed. by I. H. Rorison and Roderick Hunt The Plant Seed. Development, Preservation and Germination. Ed. by I. Rubenstein, R. L. Phillips, C. E. Green and B. G. Gengenbach

Endogenous Plant Growth Substances in Developing Fruit of Prunus cerasus L

A polar gibberellin active in the dwarf rice (Oryza sativa L.) seedling and barley (Hordeum vulgare L.) half-seed assays was extracted from immature sour cherry (Prunus cerasus L.) seed and identified as gibberellin A(32) by gas-liquid chromatography and selected ion monitoring.

Endogenous Plant Growth Substances in Developing Fruit of Prunus cerasus L. VI. Cytokinins in Relation to Initial Fruit Development1

Abstract Ethanolic extracts of sour cherry (Prunus cerasus L. cv. Montmorency) fruit were partitioned into butanol and water-soluble fractions. Following paper chromatography, each fraction was tested for cytokinin activity by the radish cotyledon and soybean callus bioassays. Activity in both fractions increased between 14 and 21 days after anthesis, and remained high at 28 days, although cell division in the pericarp had ceased. One growth promotor in the butanol fraction resembled zeatin in its chromatographic mobility on both paper and Sephadex LH-20, and was identified as zeatin by gas chromatography-mass spectrometry of its trimethylated derivative. A water-soluble growth promoter, which exhibited activity in only the radish cotyledon bioassay, was unaffected either by acid or by alkaline phosphatase hydrolysis.

Endogenous Plant Growth Substances in Developing Fruit of Prunus cerasus L. V. Changes in Inhibitor (ABA) Levels in the Seed and Pericarp1

Abstract Abscisic acid (ABA) was isolated from sour cherry (Prunus cerasus L. cv. Montmorency) fruit and identified by thin-layer and gas-liquid chromatography and combined gas chromatography-mass spectrometry. Inhibitor levels in the seed paralleled those in the pericarp and were, in general, directly related to growth rate of the fruit, higher levels being found during the initial rapid growth (Stage I) than during the retarded growth phase (Stage II). The level of the inhibitor increased in Stage III, then decreased in the final stages of maturity. The possible role of endogenous ABA in cherry fruit development is discussed.

Endogenous Plant Growth Substances in Developing Fruit of Prunus cerasus L. III. Isolation of Indole-3-acetic Acid from the Seed1

Abstract Acidic ethyl ether-soluble growth substances extracted from sour cherry (Prunus cerasus L. cv. Montmorency) seeds were subjected to repeated paper chromatography. A growth promoting substance was isolated, active in both the Avena first internode and Avena curvature bioassays, with chromatographic and chromogenic properties similar to those of indole-3-acetic acid (IAA). This tentative identification was strengthened by gas-liquid co-chromatography of the trifluoroacetyl derivatives of authentic IAA and the endogenous growth promoter. Conclusive confirmation that the growth promoting substance is IAA was provided by combined gas chromatography-mass spectrometry.

Endogenous Plant Growth Substances in Developing Fruit of Prunus cerasus L. IV. Extractable Auxin in the Seed and Pericarp1

Abstract Endogenous acidic and neutral growth-promoting substances were extracted from sour cherry (Prunus cerasus L. cv. Montmorency) seed and pericarp tissues, separated by ascending paper chromatography and detected by the Avena first internode bioassay. Although correlations were established between the levels of seed auxin and concomitant development of the nucellus and integuments and the development of the endosperm and embryo, no correlation was found between the levels of seed and pericarp auxin or between the level of pericarp auxin and concomitant fruit development.

Endogenous Plant Growth Substances (Studies in Biology No. 40)

Endogenous Plant Growth Substances (Studies in Biology No. 40)

Endogenous Plant Growth Substances in Developing Fruit of Prunus cerasus L. I. Levels of Extractable Gibberellin-Like Substances in the Seed1

Abstract Levels of gibberellin (GA)-like substances were determined in sour cherry (Prunus cerasus L.) seed in relation to fruit development using the cucumber and dwarf pea bioassays. Two GA-like substances were found; one was soluble in ethyl acetate and the other, a more polar substance, in butanol. Concentrations of both substances increased to a maximum 14 days after anthesis and then decreased and remained low during Stage III. Changes in seed GA-like substances coincided with development of the seed components, nucellus, endosperm, and embryo, and the early enlargement of the pericarp, but not with subsequent development of the pericarp. Both the ethyl acetate- and butanol-soluble GA-like seed substances chromatographed at a lower Rf than GA3. The butanol-soluble component is probably not a glycoside, since no ethyl acetate-soluble GA was released on hydrolysis. The butanol-soluble component resembles GA32 in polarity, partitioning characteristics and Rf.