Effects Of Morphactin Research Articles

Physiological and biochemical effects of morphactin IT 3233 on callus and tumour tissues of Nicotiana tabacum L. cultured in vitro III. Transamination processes catalysed by aminotransferase L-alanine: 2-oxoglutarate

An active alanine transaminase was found both in callus and tumour tissues of tobacco. The enzyme is more active in the latter tissue, and the reaction balance is strongly shifted towards alanine production, while in callus tissue towards glutamic acid formation. Morphactin applied to the tissue cultures stimulates markedly the enzyme activity only in callus. A negative correlation was observed between the intensity of transamination processes and enhanced synthesis of proteins in the tissues studied. Morphactin disturbs nitrogen metabolism in the callus tissue. Tumour tissue is more resistant to the action of this substance. The different hormonal activities in these tissues may be the cause of the different effects of morphactin.

Effects of morphactin and paclobutrazol flowering treatments on shoot and root phenology in mango cv. Kensington Pride

Mango cv. Kensington Pride, is the major horticultural tree crop in the tropical region of northern Australia. The warm, humid climate encourages vegetative growth and growers need to implement flowering treatments to maximise opportunities for high fruit yields. Two chemical-based flowering treatments have recently been introduced to the north Australian mango region. The first, paclobutrazol (P), inhibits the synthesis of gibberellins and is applied as a soil drench. The second, known as mango flowering treatment (M), uses the plant growth regulator morphactin which is applied by tying a length of twine that has been soaked in a solution of the chemical into a cincture cut around the circumference of the tree trunk. This experiment evaluated the effects of P and M on shoot phenology and the relationship between vegetative and floral growth of trees grown on nine commercial orchards in the Darwin–Katherine region of northern Australia over three consecutive seasons. In a supplementary experiment the effects of M on root growth were studied. In the year following application of P and M trees generally flowered more profusely, with the maximum intensity of flowering being up to twice that of control (C) trees at some sites. The effectiveness of M was not as consistent in the second year and by the third year this treatment had no effect on flowering. The P treatment consistently improved flowering but the attainment of maximum intensity of flowering in the Darwin region was delayed in the third year when there were fewer cool days in the pre-flowering period compared with the first 2 years. Vegetative growth was reduced by M and P at many sites, with canopy surface area of trees in these treatments being 20–30% lower than in C. Root growth of M trees was restricted to levels that were generally 33–50% of the growth achieved in C, although by the end of the year following treatment root growth in M and C was similar. Growers need to implement flowering treatments to maximise the potential for flowering of mango cv. Kensington Pride in the Australian tropics. The P treatment usually enhances flowering but may require a sustained period of cool weather in the pre-flowering period for maximum effect. The M treatment usually enhances flowering in the season following treatment but loses its effect in subsequent seasons. Root growth is reduced in M during the season following treatment which may be associated with the effects on vegetative growth and flowering and also affect the ability of trees to take up water and nutrients.

Effects of Morphactin and DCPTA on Stem Growth and Bioinduction of Rubber in Guayule

Morphactin applied to stems of guayule (Parthenium argentatum Gray) at rates of 1000 and 5000 ppm caused significant increases in stem diameter over non-treated controls after 120 days. However, rubber content remained unchanged. Additional treatment with DCPTA did not stimulate rubber accumulation in the morphactin-treated plants. Morphactin treatments also caused a decrease in plant dry weight. Morphactin and DCPTA in combination appeared to have a negative, synergistic effect on plant growth. Lack of rubber accumulation in morphactin-treated plants was attributed to disorganized, convoluted, vascular cells within the cortical tissue, which is the primary site of rubber accumulation. Chemical names used: methyl-2-chloro-9-hydroxy-fluorene-9-carboxylate (morphactin); 2-(3,4-dichlorophenoxy)-triethylamine (DCPTA).

Effects of Morphactin and Other Auxin Transport Inhibitors on Soybean Senescence and Pod Development

Because triiodobenzoic acid increases pod number, albeit variably, in soybean (Glycine max), we tested other auxin-transport inhibitors. Morphactins, especially methylchlorflurenol (MCF), were found to be very active (optimal concentration 10 micromolar) when sprayed onto the foliage. Applications at 1 week after the start of flowering were most effective, producing a 40% increase in pod number with little inhibition (12%) of stem elongation. MCF increased the number of pods initiated (reaching 1 cm length) at least partially by prolonging the initiation period, while pod abortion (failure of pods > 1 cm long) remained low. Generally, MCF did not increase seed yield (dry weight/plant); more, but smaller seeds, were formed by the treated plants. The promotive effect of MCF on pod initiation seems to be independent of its inhibition of stem elongation, which is insignificant at 10 micromolar. MCF delayed pod maturation by 3 to 4 days, while foliar yellowing, blade abscission, and petiole abscission were retarded by 2, 4, and 2 days, respectively. MCF has only a small effect on senescence and that could be indirect, due to a delay in pod development. Other auxin-transport inhibitors tested, including N-1-naphthylphthalamic acid, produced little or no increase in pod number; however, 0.1 millimolar 5-[2'-carboxyphenyl]-3-phenylpyrazole caused a 27% increase. These results implicate auxin as a potential regulator of pod development, and they show that soybean seed yield is not simply sink limited.

Temporal morphology and cap formation in Acetabularia--II. Effects of morphactin and auxin.

In order to support the hypothesis that circadian rhythms are implicated in cap formation, experiments were undertaken on the possible time-dependency of the effects of (a) a competitive inhibitor of auxins, morphactin and (b) of auxin (IAA). It was found that: (i) the inhibitory effect of morphactin varies dramatically with the time at which the several weeks' treatment was first begun; (ii) the maximum inhibition varies with development and decreases with time; (iii) IAA accelerates cap formation when the algae are submitted to IAA during the exponential growth phase; the effect is time dependent and decreases with time; (iv) IAA first applied on smaller algae has a transient inhibitory effect which is time dependent; (v) anucleate fragments also respond differentially to an IAA treatment begun at several times in the 24-hr cycle, most clearly when newly formed mRNA have been accumulated and (vi) the effect of iAA is not cumulative with that of a LD shift; that of morphactin is not, or only slightly, improved by a LD shift.

Influence of Morphactin on Leaf Morphology and Stomatal Apparatus of Vigna radiata (L.) Wilczek

Abstract The present paper reports the effects of morphactin on leaf morphology and stomatal apparatus of Vigna radiata. Morphactin treated plants showed fusion of leaflets resulting in the formation of a simple leaf with various modifications or amplification giving rise to tetra-, penta-, and multifoliate leaves simulating palmate leaves. The area of leaflets and petiole size of treated plants were considerably reduced. Morphactin also changed the form of stomata with paracytic, anisocytic and anomocytic types observed. A reduction in frequency of stomata, size of epidermal cells, trichomes and stomatal pore were common with an increase in stomatal size on the abaxial surface. Aberrations such as contiguous stomata, stomatal degeneration and stomata having a single guard cell were noted. Since the action of morphactin is in the direction of reducing transpiration, the application of this substance may be helpful in cultivation of crops exposed to periodic dry conditions.

Effect of morphactin on fruit and seed development in Nicotiana rustica Linn.

Summary The post-pollination effects of a morphactin, chloroflureno-methylester (methyl-2-chloro-9-hydroxyfluorene-9-carboxylic acid) on Nicotiana rustica Linn , are reported. Plants that were already flowering were sprayed with the morphactin solution. The flower buds which opened up to 6 days after the treatment were hand-pollinated with pollen grains collected from untreated plants. Some of these pollinated flowers were used to study pollen germination, pollen tube growth, embryo and endosperm development, and the remaining flowers were left to fruiting stage. The fruits were harvested and analyzed 3 weeks after pollination. Morphactin did not affect pollen germination and pollen tube growth. Although fruit development was normal, morphactin induced abscission of many of the developing fruits and also drastically reduced the seed set at concentrations higher than 1 ppm. These effects of morphactin depended also on the age of the flower at the time of treatment.

Opposing effects of morphactin on the rooting of cuttings in the presence or absence of auxin

SummaryThe formation of adventitious roots on stem cuttings of French bean (Phaseolus vulgaris L.) and justicia (Justicia gendarussa L.) was inhibited by pre-treatment of the stock plants with the growth inhibiting morphactin, Chlorflurenol (2-chloro-9-hydroxyfluorene-9-carboxyIic acid). The basal application of IBA to French bean and NAA to justicia cuttings, before planting, counteracted the inhibitory effect of morphactin. In the presence of auxins, cuttings from the morphactin-pre-treated stock plants rooted more than cuttings from the control plants.

Effects of Morphactin and α- Naphthylacetic Acid on the Growth of Dwarf and Normal Rice

Effects of Morphactin and α- Naphthylacetic Acid on the Growth of Dwarf and Normal Rice

Effects of Morphactin on Indol-3yl-acetic Acid Transport, Growth, and Geotropic Response in Cereal Coleoptiles

The effects of the morphactin 2-ehloro-9-hydroxyfluorene-9-carboxylic acid methyl ester [CFM] on growth, geotropic curvature and transport and metabolism of indol-3yl-acetic acid [IAA-5-3H] in the coleoptiles of Zea mays and A vena saliva have been investigated. A strong correlation has been found to exist between the inhibition of the geotropic response and the inhibition of auxin transport. CFM supplied at concentrations sufficient to abolish auxin transport has been shown to promote the elongation of Zea, but not of Avena, coleoptile segments. CFM does not change the pattern of metabolism of IAA in Zea coleoptile segments. In these segments IAA is metabolized when its concentration is high, but the radioactivity transported basipetally, or laterally in geotropically stimulated coleoptiles, is virtually confined to the IAA molecule. Radioactivity exported into the basal receiver blocks is wholly confined to IAA. It is concluded that CFM inhibits the geotropic response in coleoptiles by suppression of the longitudinal and lateral auxin transport mechanisms. The growth-promoting properties of this substance cannot be linked with its effects on either auxin metabolism or transport.

Effects of Morphactin, a New Plant Growth Substance

Effects of Morphactin, a New Plant Growth Substance

Effects of morphactin on the negative geotropic response and leaf senescence

Effects of morphactin on the negative geotropic response and leaf senescence