Plant steroid alcohols, plant sterols, are essential components of cell membranes that perform many functions. Their most prominent function is maintaining membrane semipermeability and regulating its fluidity through their specific interaction with phospholipids and membrane proteins. This work is focused on the study of the interaction of two groups of plant sterols, brassinosteroids (BRs) and phytoecdysteroids (PE). Steroid substances belonging to both groups are important signaling molecules essential for plant growth and development, but while the first group has all the known attributes of plant hormones, the second lacks hormonal function in plants. The aim of this preliminary study was to determine at what concentration level and to what extent substances of this type are able to interact with each other, and thus influence the early growth and development of a plant. It was found that exogenously applied PE 20-hydroxyecdysone (20E) significantly reduced the level of endogenous BRs in four-day-old garden cress (Lepidium sativum) seedlings. On the other hand, exogenously applied BRs, 24-epibrassinolide (epiBL), caused the opposite effect. Endogenous 20E was further detected at the picogram level in garden cress seedlings. Thus, this is the first report indicating that this plant species is PE-positive. The level of endogenous 20E in garden cress seedlings can be decreased by exogenous epiBL, but only at a relatively high concentration of 1·10-6 M in a culture medium. The image analysis of garden cress seedlings revealed that the length of shoot is affected neither by exogenous BRs nor PE, whereas the root length varies depending on the type and concentration of steroid applied.

Laboratory of Growth Regulators Institute of Experimental Botany Czech Academy of Sciences and Palacky University CZ 78371 Olomouc Czech Republic

Zobrazit více v PubMed

Davies P.J. The Plant Hormones: Their Nature, Occurrence, and Functions. In: Davies P.J., editor. Plant Hormones, Biosynthesis, Signal Transduction, Action! Kluwer Academic Publishers; Dordrecht, The Netherlands: 2004. pp. 1–15.

Clouse S.D. The Arabidopsis Book. American Society of Plant Biologists; Rockville, MD, USA: 2011. Brassinosteroids.

Lafont R., Bouthier A., Wilson I.D. Phytoecdysteroids: Structures, occurrence, biosynthseis and possible ecological significance. In: Hrdy I., editor. Insect Chemical Ecology. Academia; Prague, Czech Republic: 1991. pp. 197–214.

Mandava N.B. Plant growth-promoting brassinosteroids. Ann. Rev. Plant Physiol. Plant Mol. Biol. 1988;39:23–52. doi: 10.1146/annurev.pp.39.060188.000323. DOI

Watanabe B. Structure-activity relationship studies of insect and plant steroid hormones. J. Pestic. Sci. 2015;40:146–151. doi: 10.1584/jpestics.J15-04. DOI

Caño-Delgado A., Yin Y., Yu C., Vafeados D., Mora-García S., Cheng J.-C., nam K.H., Li J.M., Chory J. BRL1 and BRL3 are novel brassinosteroid receptors that function in vascular differentiation in Arabidopsis. Development. 2004;131:5341–5351. doi: 10.1242/dev.01403. PubMed DOI

Fujioka S., Sakurai A. Brassinosteroids. Nat. Prod. Rep. 1997;14:1–10. doi: 10.1039/np9971400001. PubMed DOI

Bergamasco R., Horn D.H.S. Distribution and Role of Insect Hormones in Plants. Endocrinology of Insects. A. R. Liss Inc.; New York, NY, USA: 1983. pp. 627–654.

Kubo I., Hanke F.J. Chemical methods for isolating and identifying phytochemicals biologically active in insects. In: Miller J.R., Miller T.A., editors. Insect Plant Interactions. Springer; New York, NY, USA: 1986. pp. 225–249.

Dreier S.I., Towers G.H.N. Activity of ecdysterone in selected plant growth bioassays. J. Plant Physiol. 1988;132:509–512. doi: 10.1016/S0176-1617(88)80073-7. DOI

Macháčková I., Vágner M., Sláma K. Comparison between the effects of 20-hydroxyecdysone and phytohormones on growth and development in plants. Eur. J. Entomol. 1995;92:309–316.

Rothová O., Holá D., Kočová M., Tůmová L., Hnilička F., Hniličková H., Kamlar M., Macek T. 24-Epibrassinolide and 20-hydroxyecdysone affect photosynthesis differently in maize and spinach. Steroids. 2014;85:44–57. doi: 10.1016/j.steroids.2014.04.006. PubMed DOI

Kamlar M., Rothova O., Salajkova S., Tarkowska D., Drasar P., Kocova M., Harmatha J., Hola D., Kohout L., Macek T. The effect of exogenous 24-epibrassinolide on the ecdysteroid content in the leaves of Spinacia oleracea L. Steroids. 2015;97:107–112. doi: 10.1016/j.steroids.2014.12.024. PubMed DOI

Tarkowská D., Novák O., Oklestkova J., Strnad M. The determination of 22 natural brassinosteroids in a minute sample of plant tissue by UHPLC–ESI–MS/MS. Anal. Bioanal. Chem. 2016;408:6799–6812. doi: 10.1007/s00216-016-9807-2. PubMed DOI

Lehmann M., Vorbrodt H.-M., Adam G., Koolman J. Antiecdysteroid activity of brassinosteroids. Experientia. 1988;44:355–356. doi: 10.1007/BF01961282. DOI

Voight B., Whiting P., Dinan L. The ecdysteroid agonist/antagonist and brassinosteroid-like activities of synthetic brassinosteroid/ecdysteroid hybrid molecules. Cell. Mol. Life Sci. 2001;58:1133–1140. doi: 10.1007/PL00000927. PubMed DOI PMC

Rittenberg D., Foster G.L. A new procedure for quantitative analysis by isotope dilution, with application to the determination of amino acids and fatty acids. J. Biol. Chem. 1940;133:737–744.

Contents of endogenous brassinosteroids and the response to drought and/or exogenously applied 24-epibrassinolide in two different maize leaves