ABSTRACT
Background 2,4-Dichlorophenoxyacetic acid (2,4-D) is widely used as a broad-leaved herbicide and plant growth regulator. Related studies have shown that 2,4-D has neurotoxicity, ability to disrupt endocrine function, genotoxicity, carcinogenicity, and reproductive toxicity. Objective This experiment is conducted to investigate the effect of 2,4-D exposure on reproductive system of female rats, and to preliminarily explore the potential ameliorative effect of Lycium barbarum polysaccharide (LBP) and its possible mechanism. Methods Twenty-four SPF female SD rats with six rats in each group were randomly divided into a blank control group (deionized water 1 mL·d−1), an exposure group (75 mg·kg−1 2,4-D), an LBP control group (50 mg·kg−1 LBP), and an LBP intervention group (75 mg·kg−1 2,4-D + 50 mg·kg−1 LBP). The rats were given intragastric administration once a day for 28 consecutive days. Body weight was measured every two days. After exposure, ovary and uterus were weighed and organ coefficients were calculated; the pathological changes of ovary and uterus were detected by hematoxylin-eosin staining (HE); the level of estradiol (E2) in serum was detected by ELISA; the levels of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and malondialdehyde (MDA) in serum were measured by corresponding kits; the apoptosis of ovarian and uterine cells was detected by TUNEL fluorescence staining; and the protein expression levels of Fas, FasL, FADD, Pro-Caspase-8, Cleaved-Caspase-8, Pro-Caspase-3, and Cleaved-Caspase-3 in ovarian tissues were detected by Western blotting. Results Compared with the blank control group, the ovarian structure of the exposure group was abnormal, the number of follicles at different developmental stages decreased, morphological changes were observed, and the number of atretic follicles increased; the endometrium was incomplete, with different degrees of nuclear pseudostratification and decreased number of glands in lamina propria. Compared with the exposure group, the ovarian structure of the LBP intervention group was complete, and the follicles at different developmental stages increased in amount, remained intact, and were arranged closely; the uterine structure was relatively intact, showing decreased endometrial loss and nuclear pseudostratification. There were significant differences in the levels of SOD, GSH-Px, E2, and MDA among the four groups (F=86.1, 26.2, 43.3, and 22.3, all P<0.01). Compared with the blank control group, the levels of serum SOD, GSH-Px, and E2 decreased in the exposure group (P<0.01), while the concentration of MDA increased (P<0.01). Compared with the exposure group, the levels of serum SOD, GSH-Px, and E2 in the LBP intervention group increased (P<0.01), and the concentration of MDA decreased (P<0.01). There were significant differences in the apoptosis rates of ovarian and uterine cells among the four groups (F=64.8, 55.5, both P<0.01). Compared with the blank control group, the apoptosis rates of ovarian and uterine cells increased in the exposure group (P<0.01). Compared with the exposure group, the apoptosis rates of ovarian and uterine cells decreased in the LBP intervention group (P<0.01). There were significant differences in the expression levels of death receptor pathway-related proteins in ovarian tissues among the four groups (all P<0.05). Compared with the blank control group, the expression levels of Fas, FasL, FADD, Pro-Caspase-8, Cleaved-Caspase-8, Pro-caspase-3, and Cleaved-Caspase-3 were increased in the exposure group (P<0.05 or 0.01). Compared with the exposure group, the expression levels of above proteins were decreased in the LBP intervention group (P<0.05 or 0.01). Conclusion The study findings reveal that 2,4-D can induce oxidative stress and further mediate Fas-FasL pathway to induce apoptosis, resulting in reproductive system damage in female rats. LBP can reduce the oxidative stress level, down-regulate the expression of Fas-FasL pathway-related proteins, and reduce the apoptosis of germ cells, therefore protecting reproductive system of female rats.
ABSTRACT
Los plaguicidas están entre las principales causas de intoxicación por sustancias químicas en Colombia. Entre ellos se cuentan herbicidas como el paraquat, el glifosato y el ácido 2,4-diclorofenoxiacético (2,4-D). Este último es uno de los herbicidas más usados en el mundo y la intoxicación por causa de este tiene una presentación similar a la intoxicación por inhibidores de la colinesterasa. El abordaje clínico de la intoxicación por 2,4-D es un reto para el primer respondiente, pues el cuadro sintomático es amplio dados los diferentes efectos de la sustancia, entre los que están el gastrointestinal, el metabólico, el renal, el neurológico, y, por supuesto, el toxicológico. Si bien la alcalinización urinaria es una piedra angular del manejo, cada vez hay más información sobre la efectividad y seguridad del uso de la hemodiálisis en casos graves. En este reporte se presentan los casos de dos pacientes con ingesta de 2,4-D, los únicos reportados en Colombia.
In Colombia one of the main sources of intoxication for chemical compounds are pesticides, finding in this groups herbicides like Paraquat, Glyphosate and 2,4-D, the last is one of the most used herbicides worldwide, finding similar clinical manifestations from those intoxications due to cholinesterase inhibitors. The access to this patient might represent a great challenge for the primary responder, because the symptomatic manifestations are wide due to the different risks it configures, like gastrointestinal, metabolic, renal, neurologic, and toxicological risk. Urinary alkalization was the recommended strategy for the management of this intoxication, but the evidence so far shows better safety and effectiveness using hemodialysis in the most severe cases. Then, the clinical cases of two patients with 2,4-D intake are presented, being those the only ones reported in Colombia so far.
Os praguicidas estão entre as principais causas de intoxicação por substâncias químicas na Colômbia. Entre eles se encontram herbicidas como o Paraquat, o glifosato e o ácido 2,4-diclorofenoxiacético (2,4-D). Este último é um dos herbicidas mais usados no mundo e a intoxicação por causa deste tem uma apresentação similar à intoxicação por inibidores da colinesterase. A abordagem clínica da intoxicação por 2,4-D é um desafio para o primeiro respondente, pois o quadro sintomático é amplo dados os diferentes efeitos da substância, entre os que está o gastrointestinal, o metabólico, o renal, o neurológico, e, por suposto, o toxicológico. Se bem que a alcalinização urinária é uma pedra angular do manejo, cada vez mais há mais informação sobre a efetividade e segurança do uso da hemodiálise nos casos graves. Neste reporte se apresentam os casos de dois pacientes com ingestão de 2,4-D, os únicos reportados na Colômbia.
Subject(s)
Humans , 2,4-Dichlorophenoxyacetic Acid , Poisoning , Renal Dialysis , AlkalinizationABSTRACT
RESUMO O ácido 2,4-diclorofenoxiacético (2,4-D) é o segundo herbicida mais consumido no Brasil e seus efeitos na contaminação dos recursos hídricos e consequente risco sanitário para abastecimento público são conhecidos. O 2,4-D e seu principal produto de degradação, o 2,4-diclorofenol (2,4-DCP), apresentam potencial de desregulação endócrina, e o ácido 2,4,5-triclorofenoxiacético (2,4,5-T) é tóxico e persistente no meio ambiente. A inexistência de uma metodologia para quantificação simultânea desses compostos motivou o desenvolvimento e a validação do método de extração e concentração de amostras ambientais e a quantificação em cromatografia líquida de alta eficiência com detector de arranjo de diodos (CLAE-DAD) para análise de 2,4-D, 2,4-DCP e 2,4,5-T em água filtrada produzida em estação de tratamento de água e água de manancial superficial. Os resultados de extração em fase sólida e a concentração da amostra demonstraram recuperação de 89 a 119%, e desvio padrão entre 0,9 e 11,4%. Para os ensaios de identificação e quantificação, os limites de detecção variaram entre 0,17 e 0,51 µg.L-1 e limite de quantificação de 1,0 µg.L-1. Os resultados mostraram que é possível empregar esse método na quantificação do 2,4-D, do 2,4-DCP e do 2,4,5-T em monitoramento ambiental e em sistemas de abastecimento de água atendendo às legislações brasileiras.
ABSTRACT The 2,4-dichlorophenoxyacetic acid (2,4-D) is the second most consumed herbicide in Brazil and their effects in the contamination of the water resources and consequent sanitary risk for public supply are known. The 2,4-D and its main degradation product, 2,4-dichlorophenol (2,4-DCP), have the potential for endocrine disruption and 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) is toxic and persistent in the environment. The absence of a methodology that simultaneously determines these compounds led to the development and validation of the solid phase extraction method, environmental samples concentrations, identification and quantification in HPLC-DAD for 2,4-D, 2,4-DCP and 2,4,5-T analysisin filtered water, produced at water treatment plants, and surface water. The extraction essay and samples concentration showed recovery from 85 to 119%, standard deviation between 0.9 and 11.4%. For identification and quantification essays, detection limits ranged between 0.17 and 0.51 µg.L-1 and the quantification limit was 1.0 µg.L-1. The results showed that it is possible to employ this method for the quantification of 2,4-D, 2,4-DCP and 2,4,5-T in environmental monitoring and in water supply systems taking account of Brazilian regulatory agencies
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No último ano, o Brasil apresentou um aumento de 190% na utilização de agrotóxicos, o que implica em um grave problema de saúde pública. O ácido 2,4-diclorofenoxiacético possui classificação toxicológica I (extremamente tóxico) e por ser muito volátil, favorece a contaminação de solos, águas, animais e seres humanos. Modelo do estudo: Estudo Experimental. Objetivo: Analisar o infiltrado inflamatório de camundongos submetidos à nebulização aguda ao herbicida ácido 2,4-diclorofenoxiacético, em diferentes intervalos de tempo e concentrações. Métodos: Foram utilizados 80 camundongos Swiss machos divididos em quatro grupos (n=20): salina, baixa (3,71 x 10-3 gramas de ingrediente ativo por hectare), média (6,19 x 10-3 gramas de ingrediente ativo por hectare) e alta concentração (9,28 x10-3 gramas de ingrediente ativo por hectare). Todos os animais foram expostos às nebulizações preconizadas para cada grupo por 15 minutos, em diferentes intervalos de tempo: 24, 48, 72 e 192 horas. O protocolo de exposição contou com duas caixas ligadas a um nebulizador ultrassônico e o vestíbulo nasal de cada animal foi retirado após a eutanásia, para a análise histológica. Resultados: A contagem de mastócitos apresentou valores significativamente aumentados no grupo alta concentração, no intervalo de tempo de 48 horas, quando comparado ao de 24 horas. Conclusão: Os resultados mostraram que a exposição aguda ao herbicida ácido 2,4-diclorofenoxiacético aumenta a produção de mastócitos na cavidade nasal de animais expostos a altas concentrações, e que podem estar relacionados ao surgimento de reações alérgicas. (AU)
In the last year, Brazil presented a 190% increase in the use of agrochemicals, which implies a serious public health problem. 2,4-Dichlorophenoxyacetic acid has toxicological classification I (extremely toxic) and because it is very volatile, it favors the contamination of soils, water, animals and humans. Study model: Experimental study. Objective: To analyze the inflammatory infiltrate of mice submitted to acute nebulization to the 2.4-dichlorophenoxyacetic acid herbicide at different time intervals and concentrations. Methods: Eighty Swiss male mice were divided into four groups (n=20): saline, low (3.71 x 10-3 grams of active ingredient per hectare), medium (6.19 x 10-3 grams of active ingredient per hectare) and high concentration (9.28 x 10-3 grams of active ingredient per hectare). All animals were exposed to the nebulizations proposed for each group, for 15 minutes, at different time intervals: 24, 48, 72 and 192 hours. The exposure protocol had two boxes attached to an ultrasonic nebulizer and the nasal vestibule of each animal was removed after euthanasia for histological analysis. Results: The mast cell count showed significantly increased values in the high concentration group, in the time interval of 48 hours, when compared to the 24-hour period. Conclusion: The results showed that the acute exposure to the herbicide 2,4-dichlorophenoxyacetic acid increases the production of mast cells in the nasal cavity of animals exposed to high concentrations, which may be related to the appearance of allergic reactions. (AU)
Subject(s)
Animals , Mice , 2,4-Dichlorophenoxyacetic Acid , Inflammation , Mast CellsABSTRACT
Stevia rebaudiana (Asteraceae) is a plant of economic importance because of its medicinal properties and the presence of sweetener compounds on its leaves. These compounds can be a substitute for sucrose in a wide variety of products used by persons with diabetes and obesity problems. To standardize an efficient and effective propagation method for the different Stevia genotypes grown in Colombia, this study evaluated the effect of different combinations of the plant growth regulators 2,4-dichlorophenoxyacetic acid (2,4-D), indole-3-acetic acid (IAA), indole-3-butyric acid (IBA), 6-(gamma, gamma-dimethylallylamino) purine (2iP) and Zeatin on the induction and development of somatic embryos. Adenine and coconut water were also evaluated as supplements in the basal culture medium Murashige and Skoog Basal Salt Mixture (MS) with glutamine. The combination of 2,4-D (18.09 µM) and 2iP (7.38 µM) produced the highest number of somatic embryos per explant, which had well-defined characteristics. The genotype showed a significant effect on the embryogenic response. In the "SRQ-93" genotype, the formation and development of somatic embryos was achieved, whereas the genotypes "Bertoni" and "Morita II" only yielded embryogenic and non-embryogenic calli, respectively. The conversion to seedlings was achieved on the regeneration medium containing gibberellic acid (GA3) (0.29 µM) and activated charcoal.
Stevia rebaudiana (Asteraceae), es una planta de gran importancia económica debido a sus propiedades medicinales y a la presencia de compuestos endulzantes en sus hojas, los cuales pueden sustituir la sacarosa en gran variedad de productos utilizados por personas con problemas de diabetes y obesidad. Con el propósito de estandarizar un método de propagación eficiente y efectivo para diferentes genotipos de Stevia cultivados en Colombia, en la presente investigación se evaluó el efecto sobre la inducción y desarrollo de embriones somáticos de diferentes combinaciones de los reguladores de crecimiento vegetal 2,4-D, IAA, IBA, 2iP y Zeatina, además de los suplementos adenina y agua de coco en el medio de cultivo basal Murashige y Skoog (1962), adicionado con glutamina. Con la combinación 2,4-D (18.09 µM) y 2iP (7.38 µM) se obtuvo el mayor número embriones somáticos por explante con características bien definidas. El genotipo tuvo un efecto significativo en la repuesta embriogénica, en el genotipo "SRQ-93" se logró la formación y el desarrollo de embriones somáticos, mientras que en los genotipos "Bertoni" y "Morita II", solo se obtuvo callo embriogénico y no embriogénico respectivamente. La conversión a plántulas se alcanzó en el medio de regeneración conteniendo GA3 (0.29 µM) y carbón activado.
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Objective: To induce callus from the medicinally valuable species, Barringtonia racemosa L. (B. racemosa) whereby the formation of callus is essential for micropropagation studies and in vitro plant secondary metabolites production. Methods: The callus induction potential in B. racemosa was assessed from endosperm explant cultured on different culture media and plant hormonal treatments. Lloyd and McCown's woody plant medium and Murashige and Skoog's medium were used in the study as culture media. On the other hand, various concentrations and combinations of 2,4-dichlorophenoxyacetic acid (1.0-2.0 mg/L) and kinetin (0.5-2.5 mg/L) had been incorporated in the culture media to exert the effects of auxin and cytokinin on callus induction. Results: From the present study, it was found that the profuse [(1.681 ± 0.770) g fresh weight, (0.239 ± 0.239) g dry weight] and friable callus formation was optimally produced with desirable morphology and considerable percentage of callus induction (56.70%) in endosperm explants cultured on 1.0 mg/L 2,4-dichlorophenoxyacetic acid and 1.5 mg/L kinetin in Murashige and Skoog's medium. Conclusions: A reliable protocol for inducing callus formation of profuse and friable morphology in endosperm explant of B. racemosa had therefore been successfully established.
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Azadirachta indica, es una planta con múltiples aplicaciones tanto forestal como farmacológica. Por ende, el establecimiento del sistema de cultivo in vitro por embriogénesis somática ofrece diversas y variadas ventajas, tales como obtener plantas altamente productivas en metabolitos. En este estudio, se utilizaron secciones foliares y cotiledonares, inducidas en medios MS (1962) suplementados con: BAP sólo y combinado con ANA / 2,4-D, TDZ sólo y con ABA. La regeneración fue con MS sólo o con K + AIA y BAP + AIA. Como resultado se estableció un sistema eficiente con secciones de cotiledones, observándose organogénesis a bajas concentraciones de BAP, mientras a altos niveles de BAP (2,5 mg.L-1), así como con TDZ + ABA (0,02 + 1 mg.L-1) respectivamente favorecieron la embriogénesis somática primaria y secundaria en un 96 % y 71 % respectivamente. La regeneración fue 71 % con MS, mientras que el enraizamiento fue de 86,67 % con MS½, obteniéndose plantas completas a corto plazo.
Azadirachta indica, is a plant with multiple forest and pharmacological application. Therefore, the establishment of in vitro culture system for somatic embryogenesis offers several distinct advantages such as obtaining highly productive plant metabolites. In this study, were used sections cotyledon and leaf, induced on MS medium (1962) supplemented with: BAP alone and combined with NAA / 2,4-D, TDZ alone and ABA. Regeneration was with MS alone or with K + BAP + IAA and IAA. As a result was established an efficient system with cotyledon sections, being observed organogenesis at low concentrations of BAP, while high levels of BAP (2.5 mg.L-1) with 96 % and TDZ + ABA (0.02 + 1 mg.L-1) with 71 %, favoring the primary and secondary somatic embryogenesis. Regeneration was 71 % with MS; rooting was 86.67 % with MS½, presenting whole plants obtained short term.
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Polyacrylamide resin was synthesized via surface-initiated atom transfer radical polymerization ( SI-ATRP) method. Acrylic amide ( AM) was grafted onto the surface of the chloromethyl polystyrene resin via SI-ATRP in the CuBr/2, 2'-bipyridine ( Bpy) system as catalyst at room temperature. The compositions of polyacrylamide resin were determined by means of elementary analysis, FT-IR analysis and scanning electron microscopy ( SEM) . The adsorption properties, the parameters of kinetics and the thermodynamics of the resin were evaluated in details, respectively. As the results, adsorption capacity of 2,4-dichlorophenoxyacetic acid (2,4-D) increased with the initial concentrations of solution increasing at room temperature, and its highest adsorption capacity was 111. 0 mg/g with solution concentration of 8 mmol/L. Adsorption isotherm at room temperature was determined and modeled with Langmuir and Freundlich equations. The thermodynamic equilibrium functions were calculated to be ΔG0, hence, the adsorption was spontaneous, endothermic and entropy increasing. The kinetics fitted the pseudo-second-order well. The polyacrylamide-chloromethyl polystyrene (PAM-CMCPS) resin was used for the adsorption of 2,4-D in orange sample, and good results were obtained.
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The objective of this work was to induce direct somatic embryogenesis from segments of immature leaves of the RB872552 variety of sugarcane and to correlate this morphogenic event with oxidative stress. Two previously described protocols were utilized for the induction of somatic embryogenesis in sugarcane with different supplementations of the culture medium and different incubation conditions. For the conversion of embryos into plants was used MS medium without phytoregulators. Histological analyses and activity of antioxidant enzymes were also conducted for the embryogenic and non-embryogenic tissues. The formation of somatic embryos was obtained in 81 % of the explants with the combination of regulators 2,4-D (2,4-dichlorophenoxyacetic acid)and BAP (6-benzylaminopurine) when incubated under 16 h photoperiod. With regards to the antioxidant enzymes, there was increased activity of peroxidase and an increase in the soluble protein content in embryogenic tissues, whereas lower activities of polyphenol oxidase and catalase appeared in these tissues compared to nonembryogenic tissues. It could be inferred that oxidative stress plays an important role in the induction of somatic embryogenesis in sugarcane.
El objetivo de este trabajo fue inducir la embriogénesis somática directa en segmentos de hojas jóvenes en la variedad de caña de azúcar RB872552, e investigar la correlación de este evento morfogénico con el estrés oxidativo. Se utilizaron dos protocolos de inducción de embriogénesis somática, previamente descritos para caña de azúcar, con distintas suplementaciones en el medio de cultivo y en las condiciones de incubación. Para la conversión de embriones en plantas se utilizó el medio MS sin fitoreguladores. Se realizaron además análisis histológicas y de actividad enzimática antioxidante en tejidos embriogénicos y no embriogénicos. La formación de embriones somáticos ocurrió en 81 % de los explantes, con la combinación de los reguladores de crecimiento 2,4-D (ácido 2,4-diclorofenoxiacético) y BAP (6-bencilaminopurina) e incubación bajo un fotoperiodo de 16 h. Respecto a las enzimas antioxidantes, se observó un incremento en la actividad de peroxidasa y en el contenido de proteínas solubles en los tejidos embriogénicos, mientras que la polifenoloxidasa y la catalasa presentaron valores más bajos de actividad en estos tejidos, en comparación con los no embriogénicos. Se podría inferir que el estrés oxidativo juega un papel importante en la inducción de la embriogénesis somática en caña de azúcar.
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The objectives of this study were to establish appropriate conditions for obtaining plant regeneration and acclimatization of the 'RB92579' and 'RB93509' sugarcane cultivars and to elucidate the shoots origin through histological analysis. For both cultivars, obtaining shoots showed better results with the culture of explants on a callus induction medium containing 2.0mg L-1 2,4-dichlorophenoxyacetic acid, followed by cultivation on a shoot induction medium containing 0.1mg L-1 kinetin and 0.2mg L-1 benzilaminopurine. The MS medium without growth regulators proved to be appropriate for elongation and rooting of shoots and the use of the composed substrate of vermiculite + MS salts was effective for acclimatization. Histological analysis revealed that the origin of the shoots in both cultivars occurred through indirect organogenesis.
Os objetivos deste estudo foram estabelecer condições apropriadas para a obtenção de regeneração de plantas e aclimatização das cultivares 'RB92579' e 'RB93509' de cana-de-açúcar e elucidar a origem das brotações através da análise histológica. Em ambas as cultivares, as brotações obtidas apresentaram os melhores resultados com a cultura dos explantes em um meio de indução de calo contendo 2,0mg L-1 de ácido 2,4-diclorofenoxiacético, seguido do cultivo em meio indutor de brotações, contendo 0,1mg L-1 de cinetina e 0,2mg L-1 benzilaminopurina. O meio MS sem reguladores de crescimento foi adequado para o alongamento e enraizamento das brotações e da utilização do substrato composto de vermiculite + sais do meio MS, foi eficaz para a aclimatização. A análise histológica revelou que a origem das brotações em ambas as cultivares ocorreu via organogênese indireta.
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2,4-Dichlorophenoxyacetic acid is a component of agent orange, which was spread during Vietnam War. Due to the toxicity of this agent, several diseases may be occuring today, potentially causing social problem. The author tried to take as preliminary information for a further clinical study by examining whether 2,4-dichlorophenoxyacetic acid makes any change in the retina of a white rat histopathologically. The objects were 6 white rats of 200-300 gm in weight. After diluting 40% 2,4dichlorophenoxyacetic acid, it was injected intraperitoneally into the rats at the levels of 5 mg/kg, 10 mg/kg, 15 mg/kg of agent. The eyeballs of the each groups were enucleated on 24 hours and 3 days and examinated with an electron microscope. Histopathological changes in the retina were characterized by the degeneration of the retinal pigment epithelial cells, the photoreceptor cells, and the choriocapillaris. To prove that 2,4-dichlorophenoxyacetic acid injures human retina, experiments with futher various plans and epidemiological surveys should be provided.
Subject(s)
Animals , Humans , Rats , 2,4-Dichlorophenoxyacetic Acid , Citrus sinensis , Epithelial Cells , Injections, Intraperitoneal , Photoreceptor Cells , Retina , Retinaldehyde , Social Problems , VietnamABSTRACT
2,4-Dichlorophenoxyacetic acid, a commonly used herbicide, increased the growth of the filamentous blue-green alga, Nostoc linckia at doses upto 100 μg /ml. The herbicidetreated N2-cultures showed enhanced heterocyst frequency and N2-growth. Thus, the herbicide stimulated algal growth at the expense of molecular nitrogen under aerobic growth conditions. Rifampicin caused chain formation of heterocysts. This was effectively counteracted by 2,4-dichlorophenoxyacetic acid, suggesting a biological interaction between them at the level of the heterocyst spacing control mechanism.