Difference between Selenite and Selenate in the Regulation of Growth and Physiological Parameters of Nickel-Exposed Lettuce

Nickel is an essential plant micronutrient; however, even at low concentrations, it may be phytotoxic. Selenium is a beneficial element with an alleviating effect that has been confirmed in the case of many abiotic stresses, including metal toxicity. The aim of this study is to assess the effect of two forms of Se (Se(IV) or Se(VI)) on the phytotoxicity, accumulation, and translocation of Ni in lettuce. Nickel causes a reduction in lettuce growth and vitality of roots, probably through increased lipid peroxidation. The application of Se(IV) to a Ni-contaminated medium resulted in a further reduction of growth, especially in the presence of 6 µM Se(IV). The growth-promoting effect of Se was found only in the 2 µM Se(VI)/10 µM Ni treatment. The application of 6 µM Se, regardless of the Se form, to the Ni-containing substrate caused an increase in shoot Ni concentration. In turn, a decrease in root Ni content was found for all Se treatments. The strong aggravation of Ni phytotoxicity in the presence of 6 µM Se(IV) was most likely related to the accumulation of high Se concentration in the roots, and the combination of high root Ni accumulation caused irreversible dysregulation of cell metabolism.

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Growth of the gynophore of the peanut Arachis hypogaea. 2. Regulation of growth

Canadian Journal of Botany ◽

10.1139/b90-123 ◽

1990 ◽

Vol 68 (5) ◽

pp. 965-978 ◽

Cited By ~ 10

Author(s):

Deborah D. Shushu ◽

Elizabeth G. Cutter

Keyword(s):

Gibberellic Acid ◽

Arachis Hypogaea ◽

Indoleacetic Acid ◽

Soil Surface ◽

Triiodobenzoic Acid ◽

Arachis Hypogaea L ◽

Low Concentrations ◽

Intercalary Meristem ◽

Growth Promoting ◽

Regulation Of Growth

It was previously shown that removal of the ovary, which occupies the distal millimetre, caused cessation of growth of the gynophore and its intercalary meristem, suggesting that the ovary was a source of growth-promoting substances. Control of growth was studied in the gynophore of the peanut Arachis hypogaea L., cv. Bukene No. 2. Low concentrations of indoleacetic acid promoted growth of decapitated gynophores, whereas high levels inhibited elongation. Gibberellic acid promoted growth of the decapitated gynophores, whereas kinetin inhibited growth at all concentrations used. A combination of indoleacetic acid and gibberellic acid promoted extension growth of the decapitated gynophores above that of the intact gynophores; this was characterized, however, by a different pattern of cell division and cell elongation from that observed in the intact gynophores. Indoleacetic acid affected the "youngest" tissues, whereas gibberellic acid affected the whole length of the growing zone. High levels of indoleacetic acid caused diageotropism of the gynophores. Application of [14C] indoleacetic acid to vertical gynophores after the ovary was excised indicated that indoleacetic acid became redistributed to one side, resulting in horizontal bending. Thus an increased amount of auxin from the enlarging ovary may be involved in placing the ovary parallel to the soil surface when it reaches a suitable depth in the soil, during normal geocarpic development. Triiodobenzoic acid reduced growth when applied in lanolin as a ring between the ovary and the meristem but not when applied proximal to the meristem, suggesting that triiodobenzoic acid prevented the transport of auxin from the ovary to the meristem.

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THE IMPORTANCE OF INSULIN, CORTISOL, PROGESTERONE AND PROLACTIN FOR THE MAMMOTROPHIC EFFECT OF PREGNANT RAT SERUM

Acta Endocrinologica ◽

10.1530/acta.0.0850548 ◽

1977 ◽

Vol 85 (3) ◽

pp. 548-558

Author(s):

J. M. Peters

Keyword(s):

Culture Medium ◽

Indirect Evidence ◽

High Concentration ◽

Promoting Effect ◽

Rat Serum ◽

Pregnant Rat ◽

Low Concentrations ◽

Prolactin Content ◽

Growth Promoting

ABSTRACT In order to explain the increased mammotrophic activity of pregnant rat serum, some hormones known to have an in vitro effect on the mammary gland were added to non-pregnant rat serum and their effect compared with that of pregnant rat serum. The addition of insulin to the culture medium increased the mammotrophic effect of pregnant rat serum, but a difference between non-pregnant and pregnant rat serum could be demonstrated either in the presence or absence of a high concentration of insulin. While pregnant rat serum had a mammogenic (i. e. growth-promoting) effect, cortisol had no such effect and antagonized the mitotic activity induced by the pregnant serum. Pregnant rat serum was active at such low concentrations, that the progesterone content of pregnant rat serum could not explain the mammogenic activity of the latter. Moreover, the combination of progesterone with non-pregnant rat serum did not produce other changes produced by pregnant rat serum alone such as cytoplasmic opalescence and the localized development of vacuolization and secretion. Prolactin with non-pregnant rat serum produced a mammotrophic effect which was in all respects similar to that of pregnant rat serum. An effect could be demonstrated at 0.08 μg prolactin/ml medium. However, again pregnant rat serum was active at such low concentrations that the prolactin content of pregnant rat serum could not explain the mammotrophic effect of pregnant rat serum. Moreover, the effect of pregnant rat serum could not be blocked with rabbit anti-rat prolactin serum, but the anti-serum blocked the effect of rat prolactin added to non-pregnant rat serum. The results exclude the possibility that insulin, cortisol, progesterone or prolactin can account for the mammotrophic activity in pregnant rat serum. They provide indirect evidence for the importance of rat chorionic mammotrophin.

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Xyloglucan- and cello-oligosaccharides: Antagonists of the growth-promoting effect of H+

Physiologia Plantarum ◽

10.1034/j.1399-3054.1990.800117.x ◽

1990 ◽

Vol 80 (1) ◽

pp. 109-113 ◽

Cited By ~ 2

Author(s):

Ester P. Lorences ◽

Gordon J. McDougall ◽

Stephen C. Fry

Keyword(s):

Promoting Effect ◽

Growth Promoting

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IS THE GROWTH-PROMOTING EFFECT OF ANTIBIOTICS CONNECTED WITH THYROID FUNCTION?

Acta Endocrinologica ◽

10.1530/acta.0.0160365 ◽

1954 ◽

Vol 16 (4) ◽

pp. 365-368 ◽

Cited By ~ 4

Author(s):

Antti Telkkä ◽

A. N. Kuusisto

Keyword(s):

Thyroid Function ◽

Promoting Effect ◽

Growth Promoting

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Quantitative Relationship between Stimulus and Response in the Growth-Promoting Effect of Spirometra mansonoides Spargana on the Hypophysectomized Rat

Journal of Parasitology ◽

10.2307/3277738 ◽

1970 ◽

Vol 56 (4) ◽

pp. 840 ◽

Cited By ~ 8

Author(s):

Justus F. Mueller

Keyword(s):

Quantitative Relationship ◽

Promoting Effect ◽

Growth Promoting

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Effects of follicular fluids on the growth of porcine preantral follicle and oocyte

Zygote ◽

10.1017/s0967199408004711 ◽

2008 ◽

Vol 16 (3) ◽

pp. 239-247 ◽

Cited By ~ 8

Author(s):

T. Metoki ◽

H. Iwata ◽

M. Itoh ◽

M. Kasai ◽

A. Takajyo ◽

...

Keyword(s):

Calf Serum ◽

Follicle Development ◽

Preantral Follicle ◽

Promoting Effect ◽

Oocyte Growth ◽

Preantral Follicles ◽

Molecular Weights ◽

Heat Treated ◽

Growth Promoting ◽

Follicular Fluids

SummaryWe examined the effect of supplementing the culture medium with follicular fluid (FF) on the growth of porcine preantral follicles and oocytes. Firstly, preantral follicles were retrieved from ovaries and then FF was collected from all antral follicles that were 2–7 mm in diameter (AFF), which included large follicles of 4–7 mm in diameter (LFF) and small follicles of 2–3 mm in diameter (SFF). When preantral follicles with a diameter of 250 μm were cultured in medium containing AFF, the growth of follicles and oocytes was greater than when follicles were cultured in medium containing fetal calf serum (FCS). When this growth-promoting effect in AFF was compared for LFF and SFF, the LFF were shown to be significantly more effective than SFF. This LFF effect was lost, however, when the concentration of LFF in the medium was decreased from 5% to 0.5% or when LFF were heat treated (60 °C for 30 min) or trypsin was added. In contrast, a decrease in SFF concentration from 5% to 0.5% and heat treatment of the SFF enhanced preantral follicle growth. Furthermore, proteins obtained from LFF that had molecular weights greater than 10 kDa (LFF > 10 kDa) had similar, but relatively reduced, growth-promoting properties. The remaining three LFF protein fractions (<10 kDa or <100 kDa or >100 kDa), however, did not have these growth-promoting properties. In conclusion, the supplementation of medium with LFF, rather than serum, enhanced preantral follicle and oocyte growth. Factors that enhanced follicle development in LFF and factors that suppressed follicle development in SFF were proteins and these LFF factors ranged in size from 10 kDa to over 100 kDa.

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