Effect Of Brassinosteroids Research Articles

Effect of brassinosteroids on nucleic acids and protein content in cultured cells of Chlorella vulgaris

This study was conducted to investigate changes of nucleic acids and protein levels in response to brassinosteroid (BR) effect in the green alga Chlorella vulgaris Beijerinck. BRs had the greatest effect on growth and metabolism of algae between 24 and 36 h after treatment in the range from 10 –12 to 10 –8 M. The highest growth of the content of nucleic acids and proteins was observed in the case of brassinolide (BL) at the concentration 10 –8 M in the 36th hour of cultivation. BL and its derivatives are biologically more active than castasterone (CS). The lowest stimulatory activity was shown by homoCS. The stimulatory effect of BRs in the algae was arranged in the following order: BL > 24-epiBL > homoBL > CS > 24-epiCS > homoCS. The relationship between the structure and the biological activity of BRs in stimulation of growth and changes in the content of DNA, RNA and proteins are discussed.

Effects of Brassinosteroids on disease resistance of rice

Effects of Brassinosteroids on disease resistance of rice

Effect of brassinosteroids on growth, metabolite content and yield of arachis hypogaea

The effects of brassinolide and 24-epibrassinolide on growth, content of nucleic acids, soluble proteins, carbohydrate fractions and yield of groundnut (Arachis hypogaea L.) was studied. Brassinosteroids substantially increased the growth of the plant. Growth promotion by brassinosteroids was associated with enhanced levels of DNA, RNA, soluble proteins and various carbohydrate fractions. Exogenous application of brassinosteroids also resulted in enhanced yield and fat content.

Recent progress in brassinosteroid research

The progress of investigations in recent years of the occurrence, analysis, structure/activity relationships, physiology, role in stress responses, and applications of brassinosteroids is reviewed. Their inclusion in the category of plant hormones is now widely accepted, and much more research into the effects of brassinosteroids can be expected in future.

Effect of brassinosteroids on growth and proton extrusion in the alga Chlorella vulgaris Beijerinck (Chlorophyceae)

Brassinolide, as a plant hormone, promotes growth of a number of plant species. Similar effects are induced by its epimer 24-epibrassinolide. In this paper we discuss the effects of brassinosteroids on the growth and proton extrusion in the green alga Chlorella vulgaris (Chlorophyceae). At concentrations between 10−15 and 10−8 m, brassinolide and 24-epibrassinolide induce a significant stimulation of growth and H+ extrusion. The growth was associated with an increase in the capability of algal cells to acidify the medium, where brassinolide is biologically more active than 24-epibrassinolide.

Effects of Brassinosteroid on Vegetative and Reproductive Growth in Two Day-neutral Strawberries

The effects of brassinosteroid on growth parameters of two day-neutral strawberries (Fragaria × ananassa Duch. 'Miyoshi' and 'Enrai') grown in a greenhouse were investigated. In both cultivars, brassinosteroid increased total leaf areas by 150-180% and the number of leaves, petiole length, and number of crowns by 110-140% over the untreated control plants. Runner formation was unaffected by the brassinosteroid. Dry weights of leaves, petioles, crowns, and total organs of plants treated with brassinosteroid were heavier than those of untreated plants, whereas the dry weights of roots from treated plants were equally heavy as those of the control. Brassinosteroid significantly increased the total number of flowers and number of inflorescences per plant, but not the number of flowers per inflorescence. Brassinosteroid significantly increased total marketable berries and total yield per plant in 'Miyoshi', but it did not increase yields of 'Enrai'.

Effects of Brassinosteroid on Cell Division and Colony Formation of Chinese Cabbage Mesophyll Protoplasts.

Effects of epibrassinolide (EBR), one of the brassinosteroids (BRs), on culture of Chinese cabbage mesophyll protoplasts were researched. The addition of EBR to the liquid culture medium increased the cell division rate and the amount of soluble protein of the protoplasts during culture. These results showed that EBR enhanced cell reproduction of Chinese cabbage mesophyll protoplasts. EBR 10-1 mg/L was especially effective. After 3 weeks of culture, there were more cell clusters in the petri dishes containing EBR than in those not containing EBR. The number of clusters increased in direct proportion to the EBR concentration. The clusters in liquid medium were transferred to agarose solidified medium which contained the same concentration of EBR as liquid culture, and after that colony formation was observed. As the result, the addition of 10-1 mg/L EBR obviously enhanced colony formation of the protoplasts. It was shown that EBR was effective in multiplication of the protoplasts.

Effects of brassinosteroids on conditioning and germination of clover broomrape (Orobanche minor) seeds

Brassinolide [2α, 3α, 22R,23R-tetrahydroxy-24S-methyl-B-homo-7-oxa-5-α-cholestan-6-one] and its related compounds, brassinosteroids, applied at the early stages of conditioning shortened the conditioning period required before clover broomrape seeds would germinate after exposure to germination stimulants, such as dl-strigol and natural stimulants from red clover (Trifolium pratense L.) root exudate. Brassinosteroids applied after conditioning increased the rate of the seed germination induced by these stimulants. The inhibitory effect of light on seed germination when it was induced by dl-strigol could be overcome by brassinosteroids. Brassinosteroids also eliminated the inhibitory effects of light and dl-strigol applied at the early stages of conditioning. GA3 was also effective in causing seed conditioning and increased the rate of the germination induced by these stimulants. There was a relationship between brassinosteroids and GA3 in many of the experiments conducted. These findings may have practical implications in increasing the effectiveness of applying germination stimulants in the field to soils for ‘suicidal germination’ of broomrape seeds.

Stimulation of source-applied14C-sucrose export inVicia fabaplants by brassinosteroids, GA3and IAA

The effect of brassinosteroids (SSHB, 24-Epi), GA 3 and IAA on sucrose uptake and export from source leaf was studied in Vicia faba plants. Brassinosteroids, GA 3 and IAA applied exogenously to the source leaves were found to enhance the retention of 14 C-label and stimulate the uptake in discs of source leaves during 4-h treatment. The hormone-promoted sucrose uptake is probably due to modulation of the H + -ATPase activity as indicated by increasing V max -values for sucrose uptake. Enhanced transport of 14 C-compounds to the apical sink region was observed in SSHB- and GA 3 -treated plants after 24 h

Effects of brassinosteroids on growth and yields of crops.

Effects of brassinosteroids on growth and yields of crops.

Effect of brassinosteroid on cell division and enlargement in cultured carrot (Daucus carota L.) cells

When added at 3.10(-6) mM to auxin-starved suspension cultured carrot (Daucus carota L.) cells, the steroid hormone 24-epibrassinolide (BR) induces cell enlargement but not cell division.This is at variance from the effect of 2,4-D which, in the same experimental conditions, restores cell division without having any effect on cell enlargement.Furthermore, in the tested experimental conditions, the effect of BR is dominant over the effect of 2,4-D when the two hormones are simultaneously supplied to the auxin-starved culture.

The effect of brassinosteroid and 2,4‐D‐L‐amino acid conjugates on ethylene production by etiolated mung bean segments

Brassinosteroid (BR) an analogue of brassinolide was tested in combination with thirteen 2,4‐dichlorophenoxyacetic acid‐L‐amino acid conjugates for its possible synergistic effects on ethylene production by etiolated mung bean (Vigna radiata L. Rwilcz cv. Berken) hypocotyl segments. When BR was used in combination with 2,4‐D‐L‐amino acid conjugates the degree of enhanced ethylene production varied with the conjugate tested. In fact, the activity of the conjugate alone was directly related to its activity with BR.

The effect of brassinosteroid on auxin‐induced ethylene production by etiolated mung bean segments

Brassinosteroid, an analogue of brassinolide, (BR) (2α, 3α, 22β, 23β‐tetrahydroxy‐24β‐methyl‐B‐homo‐7‐oxa‐5α‐cholestan‐6‐one), was tested in conjunction with indole‐3‐acetic acid (IAA), naphthaleneacetic acid (NAA), 2,4‐dichlorophenoxyacetic acid (2,4‐D), indole‐3‐butyric acid (IBA), indole‐3‐propionic acid (IPA), indole‐3‐pyruvic acid (IPyA), indole‐3‐aldehyde (IAld), indole‐3‐carbinol (ICB) or tryptophan (TRP) for its effects on ethylene production by etiolated mung bean (Vigna radiata (L.) Rwilcz cv. Berken) hypocotyl segements. The enhancement of ethylene production due to BR was greatest in conjunction with 1 μM IBA, 2,4‐D, IAA, or NAA (these increases were 2580, 2070, 890, and 300%, respectively). When increasing concentrations of IBA, 2,4‐D, IAA, or NAA were used, there was a decrease in the percentage stimulation by BR. Both IPyA and IPA had different optimal concentrations than the other auxins tested. Their BR‐enhanced maximum percentage stimulations (1430 and 1580%) were greatest with 5 μM IPya and 10 μM IPA, respectively. There was a marked reduction in the percentage stimulation by BR with either 100 μM IPyA or IPA. The inactive indoles (IAld, ICB, or TRP) did not synergize with BR at any of the concentrations tested. Four hours following treatment those segments in contact with 1 μM BR with or without the addition of 10 μM IAA began to show a stimulation in ethylene production above the control and this stimulation became greater over the following 20 h. It was necessary for BR to be in continual contact with the tissue to have a stimulatory effect on auxin‐induced ethylene production. When segments excised from greater distances below the hypocotyl hook, were treated with either IAA alone or in combination with BR, there was a decrease in ethylene production with increasing distance. There was no effect of hypocotyl length on BR stimulation of auxin‐induced ethylene production; however, there was a definite decrease in ethylene production when IAA was applied alone.