Related Experiment Video
Updated: Jun 17, 2026
07:07
A High-Resolution, Single-Grain, In Vivo Pollen Hydration Bioassay for Arabidopsis thaliana
Published on: June 30, 2023
Class B beta-expansins are needed for pollen separation and stigma penetration
Elene R Valdivia1, Andrew G Stephenson, Daniel M Durachko
1Department of Biology, The Pennsylvania State University, University Park, PA 16802, USA. elenevaldivia@gmail.com
Sexual Plant Reproduction
|December 25, 2009
Summary
Maize pollen beta-expansins are crucial for fertilization. Deficiencies in these allergens impair pollen dispersal, silk penetration, and overall pollen tube growth, impacting reproductive success.
Area of Science:
- Plant Biology
- Molecular Biology
- Genetics
Background:
- Group 1 grass pollen allergens are beta-expansins involved in cell wall loosening.
- These allergens are divided into two classes (A and B) and proposed to aid pollen tube penetration.
- Previous studies indicated a role in pollen competition and fertilization.
Purpose of the Study:
- To further investigate the function of maize group 1 allergens (pollen beta-expansins).
- To elucidate their role in pollen development, dispersal, and fertilization.
- To understand the specific contributions of beta-expansin classes A and B.
Main Methods:
- Analysis of a maize mutant with a transposon insertion in a group 1 allergen gene.
- Phenotypic characterization of pollen development and dispersal in the mutant.
- Creation and analysis of a silencing construct targeting class B genes.
Main Results:
- Pollen deficient in beta-expansin showed impaired dispersal and aggregation.
- Pollen tubes exhibited difficulties in penetrating the silk.
- Reduced expression of class B genes led to similar phenotypes, including reduced transgene transmission.
- These findings support the role of beta-expansins in multiple stages of pollen function.
Conclusions:
- Group 1 allergens (pollen beta-expansins) are essential for maize pollen development and function.
- They play critical roles in anther dehiscence, pollen tube entry into the silk, and growth within the transmitting tract.
- Understanding these allergens provides insights into plant reproductive strategies and potential applications in crop improvement.
Related Concept Videos
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.
01:17Understanding Species and Reproductive Barriers
A species is a group of organisms that interbreed and produce fertile offspring. Typically, individuals of the same species appear similar and share common characteristics due to their highly similar genomes. However, not all organisms that look alike are members of the same species. Various mechanisms keep most species discrete. While some mechanisms prevent reproductive behavior and fertilization (pre-zygotic isolation), others prevent the production of fertile offspring after mating has...
01:21Frequency-dependent Selection
When the fitness of a trait is influenced by how common it is (i.e., its frequency) relative to different traits within a population, this is referred to as frequency-dependent selection. Frequency-dependent selection may occur between species or within a single species. This type of selection can either be positive—with more common phenotypes having higher fitness—or negative, with rarer phenotypes conferring increased fitness.Positive Frequency-Dependent SelectionIn positive...
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.
02:39The 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.
02:16Genetics of Speciation
Speciation is the evolutionary process resulting in the formation of new, distinct species—groups of reproductively isolated populations.The genetics of speciation involves the different traits or isolating mechanisms preventing gene exchange, leading to reproductive isolation. Reproductive isolation can be due to reproductive barriers that have effects either before or after the formation of a zygote. Pre-zygotic mechanisms prevent fertilization from occurring, and post-zygotic mechanisms...