Morphological and Physiological Effects of Maleic Hydrazide on Tobacco

Tobacco plants (Nicotiana tabacum cv. Burley 21) were cultured in the greenhouse to the 18-leaf stage. The apical meristem was removed and subsequent axillary bud growth was removed by hand (controls) or axillary bud development was inhibited by application of maleic hydrazide. Compared with the controls, maleic hydrazide treated plants had a decreased stem diameter and stem weight, but an increased leaf weight and leaf weight/area. Plant height and leaf area were the same for both treatments. Maleic hydrazide inhibited translocation of ¹⁴C from a single leaf exposed to ¹⁴CO₂. Respiration was greater than in the controls three days after application of maleic hydrazide, but 9 and 14 days after application there were no differences in respiration between the two treatments. Maleic hydrazide did not affect photosynthetic activity.     

Influence of PGRs on carbohydrate content in Lipaphis erysimi (Kalt.)

Six compounds (IBA, chlorogenic acid, cytokinine, GA3, alar B-9 and maleic hydrazide) belonging to four different categories of plant growth hormones were used to study their effect on carbohydrate content in L. erysimi. The second instar nymphs (48 hr old) were given both dipping and leaf surface treatment with 1024 ppm concentration of compounds for two time intervals i.e. 48 and 96 hr. The carbohydrate content decreased after treatment with 4 of the plant growth regulators i.e. GA3, alar B-9, IBA and chlorogenic acid with maximum suppression in GA3 treatment. Cytokinine did not induce any derogatory influence on carbohydrate content. The treatment with maleic hydrazide, on the other hand enhanced the carbohydrate content. It could be concluded that the application of these PGRs affected the carbohydrate synthesis or metabolism.     

The Development of Embryo, Endosperm, and Nucellus Tissues in Relation to Receptacle Growth in the Strawberry

Maleic hydrazide was applied to strawberry plants in an attemptto inhibit the growth of specific tissues within the developingachenes so as to trace their function as sources of stimulito the developing receptacles. Whole plants were sprayed at 1, 500 p.p.m. at various intervalsbefore and after the opening of the primary flower on the truss.Regular twice weekly sprays with various concentrations of 2-naphthoxyaceticacid at concentrations between 50 and 5oop.p.m. were also combinedwith the maleic hydrazide treatments. Observations were madeon the development and final weight of all fruits, and valuesobtained for the percentages of achenes in which there wereviable embryos at maturity. Achenes treated with maleic hydrazideat various intervals were examined to determine the effectsof the treatment on the development of the embryo, endosperm,and nucellus. If treatment with maleic hydrazide was delayeduntil the third day after anthesis the receptacles were ableto develop and to ripen successfully even though all the acheneson their surface were devoid of viable embryos. Maleic hydrazideat 1, 500 p.p.m. was totally inactive as an inhibitor of receptacleexpansion if treatment was delayed till later than the 10thday after anthesis. It is concluded that the embryo is not the source of the growthstimulus which promotes the development of the receptacle, andthat the endosperm probably does not become active as a majorsource of auxin-like substances until it has become cellularbetween 10 and 14 days after anthesis. The possible identityof the tissue controlling receptacle-growth in the period immediatelyfollowing pollination and fertilization is discussed.     

Changes in the rhizosphere microflora of maize seedlings by pretreatment of roots with hormones and urea

Summary Effect of pretreatment of root of maize seedlings with gibberellic acid, maleic hydrazide and urea was investigated. Gibberellic acid at 1 ppm stimulated the growth of fungi, bacteria, and actinomycetes in the rhizosphere region of maize seedlings while at 5 ppm concentration population of bacteria and actinomycetes were suppressed. Maleic hydrazide treatment stimulated all the three groups at 5 ppm concentration but at 1 ppm there was increase in population of only fungi and actinomycetes. Urea stimulated the growth of fungi, bacteria, and actinomycetes. The order of predominance of different groups also changed with treatments. It was fungi > bacteria > actinomycetes in case of gibberellic acid at 1 ppm and 5 ppm and maleic hydrazide at 1 ppm; and bacteria > fungi > actinomycetes in case of maleic hydrazide at 5 ppm, urea at 0.1M and in control.     

Attività Fosfatasica Acida in Rapporto a CCC,Idrazide Maleica e Colchicina

Abstract

Acide phosphatase activity in relation to ccc, maleic hydrazide and colchicine — The acid phosphatase at pH 5 were determined on homogenates of roots and seedlings obtained from barley seeds germinated in a solution of CCC, maleic hydrazide, colchicine and water.

The acid phosphatase is strongly stimulated from colchicine, CCC and maleic hydrazide, but the minimum time of treatment to obtain the above activation is different.

It is discussed if the obtained results can be put in relation to the ATP level required for mitosis and to the auxin's properties to intervene on the phosphor's transfer.     

Effects of 2,4-D and maleic hydrazide on the glycogen level in the embryonic development of Pimpla turionellae (L.) (Hym., Ichneumonidae)

Abstract: The effects of the herbicides 2,4-D and maleic hydrazide, which are used against wild plants in farming, on the glycogen level in the embryological development of Pimpla turionellae, an important insect species used in biological control programmes, have been investigated. Various concentrations of the applied herbicides decreased the hatching rate and glycogen levels of the eggs which were still going through embryonic development. It was observed that the glycogen level of Pimpla turionellae eggs that were not exposed to herbicides increased after 4 and 8 h during embryonic development, but decreased in the later stages (24 and 30 h). It was found that the hatching rate and glycogen levels throughout the embryonic development decreased with as the concentrations of 2,4-D and maleic hydrazide applied were increased.     

Transformed roots of Crepis capillaris--a [corrected] sensitive system for the evaluation of the clastogenicity of abiotic agents

The presence of a large number of pollutants, including mutagenic agents in the environment is a problem of a major concern. Rapid progress in plant biotechnology, especially in the development of cell transformation methods, including the production of transformed roots -- 'hairy roots' -- has opened new possibilities to use transformed root cultures in plant bioassays for the evaluation mutagenic effects of different agents. We have used Crepis capillaris hairy roots for evaluation of cytogenetic effects of mutagenic treatment. Effects of maleic acid hydrazide (MH) and X-ray treatment were analysed in chromosomal aberration, sister chromatid exchange (SCE) and TUNEL tests. Comparison of cytogenetic effects in hairy roots and roots of seedlings showed a much higher sensitivity of hairy roots, which makes them convenient material for monitoring DNA damage after mutagenic treatment.     

Effect of β-indoleacetic acid,maleic hydrazide,and 2,3,5-triiodobenzoic acid on N,P, K,and Ca accumulation by pea plants

A study was performed on the effect of various concentrations of IAA, 2,3,6-triiodobenzoic acid, and maleic hydrazide, supplied to Richter’s nutrient solution, on growth of pea plants in water cultures. After a 18-day cultivation growth was evaluated and in the plants gathered the content of total N, P, K, and Ca was estimated. Growth of experimental plants (as evaluated from fresh and dry weight) was affected by all three regulators in dependence on the concentration used. It was stimulated by lower concentrations and inhibited by higher, the production of both fresh and dry weight of the root system being stimulated by all IAA concentrations used. The ratio of root dry weight to that of the entire plant was markedly increased after application of IAA and 2,3,5-triiodobenzoic acid, whereas when applying maleic hydrazide it was only slightly increased in comparison with control. Stimulation or inhibition of growth induced by IAA treatment was accompanied by an accordingly increased or decreased accumulation of N, P, K, and Ca. Thus their utilization did not change in comparison with control. On the other hand, both inhibitory and stimulatory effects of 2,3,5-triiodobenzoic acid and maleic hydrazide on growth were associated with a relatively lower accumulation of the elements in question, resulting in an increased utilization. The distribution index of N, P, K, and Ca decreased with increasing concentrations of IAA, 2,3,5-triiodobenzoic acid and maleic hydrazide. Only the highest 2,3,5-triiodobenzoic acid and maleic hydrazide concentrations used brought about a more marked increase in the distribution index of potassium, simultaneously with a marked decrease in the distribution index of calcium.     

Translocation and Metabolism of Injected Maleic Hydrazide in Silver Maple and American Sycamore Seedlings

Studies were conducted to determine the fate of ¹⁴C-maleic hydrazide injected into the stem xylem of 1-year-old silver maple (Acer saccharinum L.) and American sycamore (Platanus occidentalis L.) seedlings. Maleic hydrazide was found to translocate to all parts of the plant within 1 day after treatment. The autoradiographs indicated that the radioactivity was accumulated in meristematic regions of the leaves. A significant amount (over 15% of the applied ¹⁴C) was exuded out of the roots into the nutrient solution after 30 days. The ¹⁴C in the nutrient solution was in the form of unchanged maleic hydrazide, whereas in plant tissue a metabolite possibly a conjugate with sugar was formed. With the passage of time, the amount of metabolite seemed to increase in proportion to that of maleic hydrazide. Approximately 30% of the applied ¹⁴C was unextractable with methanol after 30 days.     

Genotoxicity of maleic hydrazide,acridine and DEHP in Allium cepa root cells performed by two different laboratories

The purpose of this paper was to compare the results of the Allium cepa chromosome aberration assay between two laboratories under the same test protocol and at the same time, use chemicals and onions obtained in their own homeland. For this study three chemicals were selected: di(2-ethylhexyl)phthalate (DEHP), maleic hydrazide, and acridine. Both laboratories found genotoxicity with a positive dose-response relationship for maleic hydrazide and acridine. However, for DEHP the results were quite different--one of the laboratories found this compound not genotoxic but the other found a positive response. Although the comparative study was inconclusive for DEHP, it was successful for the maleic hydrazide, acridine and also for the positive control (methyl methanesulfonate). Further studies need to be performed in the case of DEPH.     

The influence of incorporated bromodeoxyuridine on mutagenicity testing by sister chromatid exchange induction inVicia faba root tip cells

The induction of sister chromatid exchanges (SCEs) inVicia faba root-tip cells after short-term (2 h) and long-term (24 h) treatments with alkylating agents (N-methyl-N-nitrosourea, ethyl methanesulphonate) and maleic hydrazide was studied. The primary roots were treated with mutagens before or after 5-bromodeoxyuridine (BrdU) incorporation into DNA and the influence of mutagen application on SCE induction in the cells with non- and BrdU-substituted chromosomal DNA. On the contrary, application of maleic hydrazide after the incorporation of BrdU into DNA strongly increased the rate of SCEs. The lowest limit concentrations of mutagens capable of significantly increasing SCE frequency in the cells with non-substituted DNA after the long-term treatment were estimated.     

Transformed roots of Crepis capillaries — a sensitive system for the evaluation of the clastogenicity of abiotic agents

The presence of a large number of pollutants, including mutagenic agents in the environment is a problem of a major concern. Rapid progress in plant biotechnology, especially in the development of cell transformation methods, including the production of transformed roots – ‘hairy roots’ – has opened new possibilities to use transformed root cultures in plant bioassays for the evaluation mutagenic effects of different agents. We have used Crepis capillaris hairy roots for evaluation of cytogenetic effects of mutagenic treatment. Effects of maleic acid hydrazide (MH) and X-ray treatment were analysed in chromosomal aberration, sister chromatid exchange (SCE) and TUNEL tests. Comparison of cytogenetic effects in hairy roots and roots of seedlings showed a much higher sensitivity of hairy roots, which makes them convenient material for monitoring DNA damage after mutagenic treatment.     

Isolation of 24-epibrassinolide from leaves of <Emphasis Type="Italic">Aegle marmelos</Emphasis> and evaluation of its antigenotoxicity employing <Emphasis Type="Italic">Allium cepa</Emphasis> chromosomal aberration assay

Brassinosteroids are of universal occurrence in plants. They have been reported to affect plant growth and development through a spectrum of physiological responses. Recently they are reported to confer resistance in plants against a number of biotic and abiotic stresses. In the present study, a brassinosteroid was isolated from Aegle marmelos Correa. (Rutaceae) which was characterized to be 24-epibrassinolide (EBL) using various spectroscopic techniques (TLC and ESI-MS analysis). It was evaluated for the antigenotoxicity against maleic hydrazide (MH) induced genotoxicity in Allium cepa chromosomal aberration assay. It was shown that the percentage of chromosomal aberrations induced by maleic hydrazide (0.01%) declined significantly with 24-epibrassinolide treatment. EBL (10⁻⁷ M) proved to be the most effective concentration with 91.8% inhibition. This is the first report on the isolation of 24-epibrassinolide from Aegle marmelos and its antigenotoxic effects against MH employing Allium cepa chromosomal aberration assay.     

Lipids in Berseem Seed (Trifolium alexandrinum) during Germination as Affected by Gibberellic Acid and Maleic Hydrazide

Lipid depletion of berseem seed treated with 100 mg/1 gibberellic acid or maleic hydrazide was studied during germination. During the first 3 days after germination there was little lipid consumption but thereafter the depletion of lipid was rapid. Gibberellic acid was found to enhance the lipid utilization of total lipids and triglyceride components during germination. On the other hand, maleic hydrazide reduced the utilization of triglycerides of the germinating seed. The rate of utilization was rapid for unsaturated fatty acids and slower for saturated ones in treated seeds as compared to untreated seeds.     

Rhythmic Growth in Excised Sprout-leaves of Onion Bulbs

Sprout leaf preparations, consisted of the inner 6 or 7 sprout leaves attached to the base plate of bulbs of Allium cepa cv. Downy Yellow Globe. The preparations excised from dormant bulbs were capable of sprouting. The elongation of the sprout leaves in the light was inhibited by a field pretreatment of 2000 mg/1 M.H.-30 (30% maleic hydrazide) and stimulated by incubation in the dark. Rapid cooling of the bulbs prior to excising of the preparations had no effect on sprouting. The ability of the sprout leaf preparations to elongate followed a cyclical time course, displaying maxima 8 to 12 weeks apart. Pretreatment with M.H.-30 inhibited this periodicity.     

The effect of maleic hydrazide on growth and mutation of a blue-green alga

Summary Maleic hydrazide is mutagenic to the blue-green alga Anacystis nidulans at pH 5.0, producing mutations to streptomycin-resistance and penicillin-resistance, and is non-mutagenic at pH 8.0, promoting growth in low concentrations. The maleic hydrazide-induced increases in the levels of streptomycin- and penicillin-resistance are 1000 and 500 times respectively over the parental strain. The resistant strains can further mutate spontaneously to give rise to strains resistant to still higher concentrations of the antibiotic.Cultures growing with manganese are more sensitive to maleic hydrazide-induced inhibition of growth than are those growing without manganese. However, cultures of the alga in maleic hydrazide grown in the presence of two different concentrations of manganese differ in the extent of growth which is better in those with the higher manganese concentration than in those with the lower. These results suggest different modes of interaction between manganese and maleic hydrazide, controlled primarily by manganese concentration.     

Estimation of mutagenicity and metabolic activation after recurrent exposures ofnicotiana tabacum L. var.xanthi to 14 pesticides

Recurrent application (17 administrations in 38 days) of 14 pesticides (Karathane FN 57, Fundazol 50 WP, Dithane M 45, Topsin M 70 WP, Perozin 75 B, Fademorf EK 20, Novozir MN 80, Metation E 50, Pirimor DP, Decemtion EK 20, Zeazin 50 DP, Fatex EK 80, maleic hydrazide and Ethrel) did not increase (with the exception of maleic hydrazide) the frequency of somatic mutations in a heterozygous chlorophyll mutant ofNicotiana tabacumL. var.xanthi n. c. None of the four tested pesticides (Fademorf EK 20, Decemtion EK 20, maleic hydrazide and Ethrel) were transformed in tobacco plants to a stable mutagenic or promutagenic product active in theSalmonella (Ames) mutagenicity assay.     

Reduced clastogenic activity of maleic hydrazide in Vicia faba seedlings grown in a situation of overcrowding stress

A pre-treatment stress situation of overcrowding of Vicia faba seedlings in the phase of germination and growth influenced their subsequent sensibility to treatment with the mutagenic herbicide maleic hydrazide. The seedlings showed a significant reduction in the frequency of micronucleated cells when they grew in a strongly crowded manner compared with scattered and uniformly distributed seedlings (3.83% versus 11.46%). The findings do not provide evidence for the involvement of phytochelatins in response to stress conditions in this process: pre-treatment with buthionine sulfoximine, a specific inhibitor of phytochelatin synthesis, did not modify the response of the seedlings to maleic hydrazide under conditions of overcrowding or under normal conditions. Scanning electron microscopy (SEM) was used to observe the root tip of V. faba grown in conditions of normal growth or overcrowding. SEM micrographs revealed differences between the tips with regards to root hair density and root surface morphology. Finally, we found a positive correlation between the frequency of micronucleated cells and the length of the primary root, for every time of growth considered (1, 3, 4 and 5 days).     

Mutagenicity and DNA-damaging activity for several pesticides tested with Bacillus subtilis mutants

The active pure compounds of 4 pesticides were tested for DNA-damaging and mutagenic activity in Bacillus subtilis and Salmonella typhimurium tester strains. Included were zinc ethylenebisdithiocarbamate (dithane), 1,2-dihydropyridazine-3,6-dione (maleic hydrazide), O,O-dimethylphosphorodithioate (malathion), and 1,2-dibromoethane (fumazone). These agents gave either weak or negative mutagenic responses with the Salmonella/microsome tests for mutagenicity, but were all positive when the tester was B. subtilis strain TKJ6321. Of the 4 chemicals, only fumazone required metabolic activation with rat-liver S9 mix. Upon activation, it produced a volatile mutagenic product. Dithane, maleic hydrazide, and malathion were all mutagenic and did not require metabolic activation. Among these agents, dithane was strongly mutagenic while fumazone, maleic hydrazide and malathion were moderately mutagenic. Only dithane gave significant DNA-damaging activity when applied to a battery of repair-deficient B. subtilis mutants. For the chemicals reported, it is concluded that B. subtilis is superior to S. typhimurium in the detection of mutagenic activity. We strongly recommend its use for prescreening procedures in combination with the S. typhimurium testers.     

Low temperature between conditioning and challenge treatment prevents the 'adaptive response' of Vicia faba root tip meristem cells.

When the temperature during intertreatment time (2 h) between conditioning and challenge treatment of Vicia faba root tip meristems with either triethylenemelamine or maleic hydrazide was reduced from 24 degrees C to 12 degrees C no adaptive response occurred any more. The yield of metaphases with chromatid aberrations under these circumstances was similar to that observed after challenge treatment alone, i.e., no reduction occurred. This indicates that the metabolic state of the cells is of critical importance for the presence or absence of adaptive responses.