Related Experiment Video
Updated: Jun 24, 2026
11:56
Non-radioactive in situ Hybridization Protocol Applicable for Norway Spruce and a Range of Plant Species
Published on: April 17, 2009
Developing fruit direct post-floral morphogenesis in Helleborus niger L
Branka Salopek-Sondi1, Maja Kovac, Tatjana Prebeg
1Ruether Bosković Institute, Bijenicka c. 54, PO Box 180, HR-10002 Zagreb, Croatia.
Journal of Experimental Botany
|August 15, 2002
Summary
Plant hormones like cytokinins and gibberellins are crucial for Helleborus niger sepal development and peduncle elongation after fertilization. Their application can restore these processes, highlighting their role in flower development.
Area of Science:
- Plant Physiology
- Reproductive Biology
- Horticultural Science
Background:
- In Helleborus niger, sepals and peduncles undergo significant changes post-fertilization.
- These developmental processes are influenced by the presence of pistils and potentially by plant growth regulators.
Purpose of the Study:
- To investigate the role of plant growth regulators in the post-fertilization development of Helleborus niger sepals and peduncles.
- To identify endogenous cytokinins involved in these developmental changes.
Main Methods:
- Experimental removal of pistils at the bud stage.
- Application of plant growth regulators (cytokinins, gibberellins, auxin) and inhibitors (paclobutrazol).
- Analysis of sepal and peduncle morphology, chloroplast development, and endogenous cytokinin levels using chromatography and mass spectrometry.
Main Results:
- Pistil removal inhibited sepal spreading and peduncle elongation, which could be restored by exogenous cytokinins and gibberellins.
- Cytokinins and gibberellins promoted chloroplast formation and sepal spreading; GA3 and auxin promoted peduncle elongation.
- Paclobutrazol inhibited chlorophyll formation, reversed sepal spreading, and reduced peduncle elongation.
- Zeatin riboside levels increased dramatically after fertilization, correlating with rapid chlorophyll accumulation in sepals.
Conclusions:
- Cytokinins and gibberellins play essential roles in the post-fertilization development of Helleborus niger sepals and peduncles.
- Zeatin riboside is a key endogenous cytokinin regulating sepal greening and development after fertilization.
Related Concept Videos
02:19Morphogenesis
Plant morphogenesis—the development of a plant’s form and structure—involves several overlapping developmental processes, including growth and cell differentiation. Precursor cells differentiate into specific cell types, which are organized into the tissues and organ systems that make up the functional plant.
02:40Pollination and Flower Structure
Flowers are the reproductive, seed-producing structures of angiosperms. Typically, flowers consist of sepals, petals, stamens, and carpels. Sepals and petals are the vegetative flower organs. Stamens and carpels are the reproductive organs.
02:39The Angiosperm Life Cycle
Plants have a life cycle split between two multicellular stages: a haploid stage—with cells containing one set of chromosomes—and a diploid stage—with cells containing two sets of chromosomes. The haploid stage is the gamete-producing gametophyte, and the diploid stage is the spore-producing sporophyte.
02:33Seed Structure and Early Development of the Sporophyte
Seed structures are composed of a protective seed coat surrounding a plant embryo, and a food store for the developing embryo. The embryo contains the precursor tissues for leaves, stem, and roots. The endosperm and cotyledons—seed leaves—act as the food reserves for the growing embryo.
01:58Fruit Development, Structure, and Function
Fruits form from a mature flower ovary. As seeds develop from the ovules contained within, the ovary wall undergoes a series of complex changes to form fruit. In some fruits, such as soybeans, the ovary wall dries; in other fruits, such as grapes, it remains fleshy. In some cases, organs other than the ovary contribute to fruit formation; such fruits are called accessory fruits.
01:10Zygotic Development And Stem Cell Formation
The development of all multicellular organisms starts with the fusion of haploid cells called sperm and egg to form a diploid zygote. A zygote is a totipotent cell that can develop into a complete organism. The zygote undergoes cell division or cleavage to form an 8-cell mass. Until this stage, the cells are spherical, loosely attached, and remain totipotent. Totipotent cells are capable of developing both the embryonic and the extraembryonic tissues. However, as they continue to divide, they...