Progestogens and androgens are steroids found in a wide range of plants, but little is known about their physiological functions. In this study, we sowed seeds of angiosperms on progestogen- and androgen-containing medium and analysed their morphological effects. We further investigated the effects of progesterone and testosterone on brassinosteroid profiles and gene expression in A. thaliana. Additionally, we examined the effects of progesterone and testosterone on A. thaliana plants overexpressing the steroid 5α-reductase DET2. We found that progestogens and androgens have strong negative effects on root length, especially in Brassicaceae species. In addition, these steroids led to uncoordinated cell growth and increased lateral root formation. We failed to detect an effect on endogenous brassinosteroid levels and gene expression of brassinosteroid-regulated genes. The overexpression of DET2 led to increased root growth, but the effects of progesterone and testosterone were not reduced. We conclude that progestogens and androgens act in a brassinosteroid-independent manner. This suggests that progestogens and androgens could represent a potential new class of plant steroid signalling molecules.

• Keywords
• Arabidopsis thaliana, DET2, androgens, brassinosteroids, phytohormones, progestogens, root development, signalling molecules,
• MeSH
• Androgens * metabolism   pharmacology   MeSH
• Arabidopsis * genetics   growth & development   drug effects   metabolism   MeSH
• Brassinosteroids * metabolism   MeSH
• Plants, Genetically Modified MeSH
• Plant Roots * growth & development   drug effects   anatomy & histology   genetics   metabolism   MeSH
• Magnoliopsida * genetics   growth & development   drug effects   metabolism   MeSH
• Progesterone pharmacology   metabolism   MeSH
• Progestins * metabolism   pharmacology   MeSH
• Arabidopsis Proteins metabolism   genetics   MeSH
• Gene Expression Regulation, Plant drug effects   MeSH
• Plant Growth Regulators * metabolism   MeSH
• Seeds growth & development   drug effects   genetics   MeSH
• Testosterone pharmacology   metabolism   MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Androgens * MeSH
• Brassinosteroids * MeSH
• Progesterone MeSH
• Progestins * MeSH
• Arabidopsis Proteins MeSH
• Plant Growth Regulators * MeSH
• Testosterone MeSH

BACKGROUND: The brassinosteroid (BR) plant hormones regulate numerous developmental processes, including those determining stem height, leaf angle, and grain size that have agronomic relevance in cereals. Indeed, barley (Hordeum vulgare) varieties containing uzu alleles that impair BR perception through mutations in the BR receptor BRASSINOSTEROID INSENSITIVE 1 (BRI1) exhibit a semi-dwarf growth habit and more upright leaves suitable for high-density planting. We used forward and reverse genetic approaches to develop novel BRI1 alleles in wheat (Triticum aestivum L.) and investigated their potential for crop productivity improvement. RESULTS: The combination of ethyl methanesulfonate-induced mutations introducing premature stop codons in all three homoeologous TaBRI1 genes resulted in severe dwarfism, malformed leaves and sterility as observed in bri1 mutants in other species. Double mutants had reduced flag-leaf angles (FLAs) conferring a more upright canopy but exhibited no differences in height or grain weight. In a targeted forward genetics screen using a double mutant, we identified two BR-insensitive lines with reduced height and FLA that contained amino acid substitutions in conserved regions of BRI-A1. The less severe mutant had a 56% reduction in FLA and was 35% shorter than the wild type, although seed set, seed area and grain weights were also reduced. The most severe mutants contained elevated levels of bioactive BRs and increased expression of BR-biosynthesis genes consistent with reduced feedback suppression of biosynthesis. CONCLUSION: Our study gives a better understanding of BRI1 function in wheat and provides mutants that could potentially be explored for improving grain yields when sown at high density.

• Keywords
• BR insensitivity, Brassinosteroids, EMS-mutagenesis, Semi-dwarf, Upright leaf angles, Wheat,
• MeSH
• Brassinosteroids metabolism   MeSH
• Phenotype MeSH
• Plant Leaves genetics   anatomy & histology   growth & development   MeSH
• Mutation MeSH
• Triticum * genetics   anatomy & histology   growth & development   metabolism   MeSH
• Plant Proteins * genetics   metabolism   MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Brassinosteroids MeSH
• Plant Proteins * MeSH

Parthenocarpic fruit development in prickly pear involves up-regulation of the transcription factor BZR1 and increased levels of brassinolide in developing ovules. We explored the complex process of parthenocarpic fruit development in prickly pear Opuntia ficus-indica (Cactaceae) by comparing the fruits of the parthenocarpic Beer Sheva1 (BS1) mutant and revertant non-parthenocarpic fruits. The mutant plants produce flowers with enlarged ovules that develop into degenerated seed-like stony structures. Pollen tubes fail to penetrate the ovule, resulting in the formation of lignified and hard seed coat brown in colour. Some new stems on BS1 plants bear normal revertant flowers containing small and viable fertilized ovules. BS1 thus provides a unique model for elucidating the regulatory mechanisms underlying parthenocarpy in prickly pear. Our working hypothesis was that parthenocarpy is induced by elevated levels of brassinolide in the ovules of BS1. By comparing transcriptomes, we identified 7717 differentially expressed genes between BS1 and the revertant among them brassinosteroid-related genes. Quantification of the brassinosteroids confirmed higher brassinolide levels and up-regulation of the brassinosteroid positive regulator BRASSINAZOLE RESISTANT1 (BZR1) in BS1 ovules compared to revertant ovules displaying normal seed development. Thereby, implicating the involvement of brassinolide in ovule development, fruit phenology, and parthenocarpy. The early flowering and fruit ripening observed in BS1 support our hypothesis that brassinolide promotes parthenocarpic fruit development and ripening.

• Keywords
• Opuntia ficus-indica, BZR1, Brassinolide, Brassinosteroids, Cacti, Fruit, Ovule, Parthenocarpy, Prickly pear,
• MeSH
• Brassinosteroids * metabolism   MeSH
• Flowers genetics   MeSH
• Mutation genetics   MeSH
• Opuntia * genetics   metabolism   growth & development   MeSH
• Fruit genetics   growth & development   metabolism   MeSH
• Gene Expression Regulation, Plant MeSH
• Plant Proteins * genetics   metabolism   MeSH
• Steroids, Heterocyclic * metabolism   MeSH
• Up-Regulation genetics   MeSH
• Ovule genetics   metabolism   growth & development   MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• brassinolide MeSH Browser
• Brassinosteroids * MeSH
• Plant Proteins * MeSH
• Steroids, Heterocyclic * MeSH

Brassinosteroids (BRs) are phytohormones which regulate various developmental processes in plants. They are exceptional phytohormones, as they do not undergo long-distance transport between plant organs. However, knowledge about the function of the enzymes that catalyse BR biosynthesis (particularly its early stages) in cereal crops remains limited. Therefore, this study identifies and analyses the function of the HvDWARF5 (HvDWF5) gene, involved in the early stage of BR biosynthesis in barley (Hordeum vulgare), an important cereal crop, using the TILLING (Targeting Induced Local Lesions IN Genomes) approach. The detailed functional analysis allowed for the identification of various mutations in different gene fragments. The influence of these mutations on plant architecture, reproduction, and yield was characterised. Moreover, effects of the missense and intron retention mutations on sequence and splicing of the HvDWF5 transcript, sequence and predicted structure of the encoded HvDWF5 enzyme, and accumulation of endogenous BR were determined. Some of the barley mutants identified in this study showed semi-dwarfism, a trait of particular importance for cereal breeding and yield. However, unlike other BR mutants in cereals, this did not negatively affect grain size or weight. It indicated that mutations in this gene allow for a balance between plant height reduction and maintenance of grain size. Thus, the results of this study provide a novel insight into the role of the HvDWF5 gene in the BR biosynthesis-dependent regulation of architecture and reproduction of the important cereal crop - barley.

• MeSH
• Brassinosteroids * metabolism   biosynthesis   MeSH
• Hordeum * genetics   metabolism   growth & development   MeSH
• Edible Grain * genetics   growth & development   MeSH
• Mutation genetics   MeSH
• Gene Expression Regulation, Plant MeSH
• Plant Proteins * genetics   metabolism   MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Brassinosteroids * MeSH
• Plant Proteins * MeSH

Brassinosteroids (BRs) are plant steroidal hormones that play crucial roles in plant growth and development. Accurate quantification of BRs in plant tissues is essential for understanding their biological functions. This study presents a comprehensive overview of the latest methods used for the quantification of BRs in plants. We discuss the principles, advantages and limitations of various analytical techniques, including immunoassays, gas chromatography-mass spectrometry and liquid chromatography-tandem mass spectrometry that are used for the detection and quantification of BRs from complex plant matrixes. We also explore the use of isotopically labeled internal standards to improve the accuracy and reliability of BR quantification.

• Keywords
• Brassinosteroids, Chemical synthesis, Chromatography, Immunoassays, Mass spectrometry, Quantification,
• MeSH
• Brassinosteroids * metabolism   analysis   MeSH
• Chromatography, Liquid methods   MeSH
• Immunoassay methods   MeSH
• Gas Chromatography-Mass Spectrometry methods   MeSH
• Plant Growth Regulators metabolism   analysis   MeSH
• Plants metabolism   chemistry   MeSH
• Tandem Mass Spectrometry methods   MeSH
• Publication type
• Journal Article MeSH
• Review MeSH
• Names of Substances
• Brassinosteroids * MeSH
• Plant Growth Regulators MeSH

The field of plant hormonomics focuses on the qualitative and quantitative analysis of the hormone complement in plant samples, akin to other omics sciences. Plant hormones, alongside primary and secondary metabolites, govern vital processes throughout a plant's lifecycle. While active hormones have received significant attention, studying all related compounds provides valuable insights into internal processes. Conventional single-class plant hormone analysis employs thorough sample purification, short analysis and triple quadrupole tandem mass spectrometry. Conversely, comprehensive hormonomics analysis necessitates minimal purification, robust and efficient separation and better-performing mass spectrometry instruments. This review summarizes the current status of plant hormone analysis methods, focusing on sample preparation, advances in chromatographic separation and mass spectrometric detection, including a discussion on internal standard selection and the potential of derivatization. Moreover, current approaches for assessing the spatiotemporal distribution are evaluated. The review touches on the legitimacy of the term plant hormonomics by exploring the current status of methods and outlining possible future trends.

• Keywords
• Hormonomics, Internal standard, Liquid chromatography, Mass spectrometry, Matrix effect, Metabolomics, Omics, Plant hormone, Solid phase extraction,
• Publication type
• Journal Article MeSH
• Review MeSH

Exogenously applied brassinosteroids (BRs) improve plant response to drought. However, many important aspects of this process, such as the potential differences caused by different developmental stages of analyzed organs at the beginning of drought, or by BR application before or during drought, remain still unexplored. The same applies for the response of different endogenous BRs belonging to the C27, C28-and C29- structural groups to drought and/or exogenous BRs. This study examines the physiological response of two different leaves (younger and older) of maize plants exposed to drought and treated with 24-epibrassinolide (epiBL), together with the contents of several C27, C28-and C29-BRs. Two timepoints of epiBL application (prior to and during drought) were utilized to ascertain how this could affect plant drought response and the contents of endogenous BRs. Marked differences in the contents of individual BRs between younger and older maize leaves were found: the younger leaves diverted their BR biosynthesis from C28-BRs to C29-BRs, probably at the very early biosynthetic steps, as the levels of C28-BR precursors were very low in these leaves, whereas C29-BR levels vere extremely high. Drought also apparently negatively affected contents of C28-BRs (particularly in the older leaves) and C29-BRs (particularly in the younger leaves) but not C27-BRs. The response of these two types of leaves to the combination of drought exposure and the application of exogenous epiBL differed in some aspects. The older leaves showed accelerated senescence under such conditions reflected in their reduced chlorophyll content and diminished efficiency of the primary photosynthetic processes. In contrast, the younger leaves of well-watered plants showed at first a reduction of proline levels in response to epiBL treatment, whereas in drought-stressed, epiBL pre-treated plants they were subsequently characterized by elevated amounts of proline. The contents of C29- and C27-BRs in plants treated with exogenous epiBL depended on the length of time between this treatment and the BR analysis regardless of plant water supply; they were more pronounced in plants subjected to the later epiBL treatment. The application of epiBL before or during drought did not result in any differences of plant response to this stressor.

• Keywords
• OJIP analysis, brassinosteroids, drought, endogenous content, exogenous application, leaf age, proline,
• Publication type
• Journal Article MeSH

Dioscorea is an important but underutilized genus of flowering plants that grows predominantly in tropical and subtropical regions. Several species, known as yam, develop large underground tubers and aerial bulbils that are used as food. The Chinese yam (D. polystachya Turcz.) is one of the few Dioscorea species that grows well in temperate regions and has been proposed as a climate-resilient crop to enhance food security in Europe. However, the fragile, club-like tubers are unsuitable for mechanical harvesting, which is facilitated by shorter and thicker storage organs. Brassinosteroids (BRs) play a key role in plant cell division, cell elongation and proliferation, as well as in the gravitropic response. We collected RNA-Seq data from the head, middle and tip of two tuber shape variants: F60 (long, thin) and F2000 (short, thick). Comparative transcriptome analysis of F60 vs. F2000 revealed 30,229 differentially expressed genes (DEGs), 1,393 of which were differentially expressed in the growing tip. Several DEGs are involved in steroid/BR biosynthesis or signaling, or may be regulated by BRs. The quantification of endogenous BRs revealed higher levels of castasterone (CS), 28-norCS, 28-homoCS and brassinolide in F2000 compared to F60 tubers. The highest BR levels were detected in the growing tip, and CS was the most abundant (439.6 ± 196.41 pmol/g in F2000 and 365.6 ± 112.78 pmol/g in F60). Exogenous 24-epi-brassinolide (epi-BL) treatment (20 nM) in an aeroponic system significantly increased the width-to-length ratio (0.045 ± 0.002) compared to the mock-treated plants (0.03 ± 0.002) after 7 weeks, indicating that exogenous epi-BL produces shorter and thicker tubers. In this study we demonstrate the role of BRs in D. polystachya tuber shape, providing insight into the role of plant hormones in yam storage organ development. We found that BRs can influence tuber shape in Chinese yam by regulating the expression of genes involved cell expansion. Our data can help to improve the efficiency of Chinese yam cultivation, which could provide an alternative food source and thus contribute to future food security in Europe.

• Keywords
• Chinese yam, Dioscorea polystachya, brassinosteroids, plant hormones, tuber development,
• Publication type
• Journal Article MeSH

Increasing crop productivity under optimal conditions and mitigating yield losses under stressful conditions is a major challenge in contemporary agriculture. We have recently identified an effective anti-senescence compound (MTU, [1-(2-methoxyethyl)-3-(1,2,3-thiadiazol-5yl)urea]) in in vitro studies. Here, we show that MTU delayed both age- and stress-induced senescence of wheat plants (Triticum aestivum L.) by enhancing the abundance of PSI supercomplex with LHCa antennae (PSI-LHCa) and promoting the cyclic electron flow (CEF) around PSI. We suppose that this rarely-observed phenomenon blocks the disintegration of photosynthetic apparatus and maintains its activity as was reflected by the faster growth rate of wheat in optimal conditions and under drought and heat stress. Our multiyear field trial analysis further shows that the treatment with 0.4 g ha-1 of MTU enhanced average grain yields of field-grown wheat and barley (Hordeum vulgare L.) by 5-8%. Interestingly, the analysis of gene expression and hormone profiling confirms that MTU acts without the involvement of cytokinins or other phytohormones. Moreover, MTU appears to be the only chemical reported to date to affect PSI stability and activity. Our results indicate a central role of PSI and CEF in the onset of senescence with implications in yield management at least for cereal species.

• Keywords
• 1-(2-methoxyethyl)-3-(1,2,3-thiadiazol-5yl)urea, MTU, cyclic electron flow, drought stress, heat stress, photosystem I, stress tolerance, wheat,
• Publication type
• Journal Article MeSH

The objective of this study was to answer the question of how the deacclimation process affects frost tolerance, photosynthetic efficiency, brassinosteroid (BR) homeostasis and BRI1 expression of winter oilseed rape. A comparative study was conducted on cultivars with different agronomic and physiological traits. The deacclimation process can occur when there are periods of higher temperatures, particularly in the late autumn or winter. This interrupts the process of the acclimation (hardening) of winter crops to low temperatures, thus reducing their frost tolerance and becoming a serious problem for agriculture. The experimental model included plants that were non-acclimated, cold acclimated (at 4 °C) and deacclimated (at 16 °C/9 °C, one week). We found that deacclimation tolerance (maintaining a high frost tolerance despite warm deacclimating periods) was a cultivar-dependent trait. Some of the cultivars developed a high frost tolerance after cold acclimation and maintained it after deacclimation. However, there were also cultivars that had a high frost tolerance after cold acclimation but lost some of it after deacclimation (the cultivars that were more susceptible to deacclimation). Deacclimation reversed the changes in the photosystem efficiency that had been induced by cold acclimation, and therefore, measuring the different signals associated with photosynthetic efficiency (based on prompt and delayed chlorophyll fluorescence) of plants could be a sensitive tool for monitoring the deacclimation process (and possible changes in frost tolerance) in oilseed rape. Higher levels of BR were characteristic of the better frost-tolerant cultivars in both the cold-acclimated and deacclimated plants. The relative expression of the BRI1 transcript (encoding the BR-receptor protein) was lower after cold acclimation and remained low in the more frost-tolerant cultivars after deacclimation. The role of brassinosteroids in oilseed rape acclimation/deacclimation is briefly discussed.

• Keywords
• brassinosteroid insensitive 1, brassinosteroids, dehardening, delayed chlorophyll fluorescence, frost tolerance, homocastasterone, photosystem I, photosystem II, prompt chlorophyll fluorescence, stress tolerance,
• MeSH
• Acclimatization physiology   MeSH
• Brassica napus * genetics   MeSH
• Brassinosteroids MeSH
• Photosynthesis MeSH
• Homeostasis MeSH
• Cold Temperature MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Brassinosteroids MeSH