Plant Molecular Development

Plant Molecular Development

• Plant Growth and Differentiation: This covers the plant life cycle, cellular cycles, determination of cellular processes, differentiating cells, growth, organogenesis, and morphogenesis.

• Plant life cycle: Plants alternate between multicellular generations to complete the life cycle.

• Meiosis products: Products of meiosis in diploid plants are spores, forming diploid sporophytes.

• Spores: Each spore undergoes mitotic divisions to create a new haploid gametophyte.

• Flowers: Specialized structures of the sporophyte that house reproduction in flowering plants; unisexual or hermaphroditic.

• Sporophyte generation: Dominant stage in seed plants (gymnosperms and angiosperms).

• Spores development: Megaspores form the female gametophyte; microspores form the male gametophyte.

• Haploid female gametophyte: Multi-cellular structure forming egg cells and supporting cells in plants.

• Embryo sac: The female reproductive structure in flowering plants (has eight cells).

• Haploid male gametophyte: A multicellular structure producing sperm nuclei and a generative nucleus.

• Pollen: The male gametophyte in seed plants.

• Double fertilization: Involves zygote and endosperm formation.

Plant Architecture

• Shoot apical meristem (SAM): Located at the tips of stems and shoots, controlling growth.

• Axillary bud meristems: Found in the leaf axils, generating lateral shoots.

• Root meristem: located at the tips of roots, leading to root growth.

• Stems: Include nodes and internodes.

• Leaves: Essential for photosynthesis.

• Roots: Anchor the plant and absorb water and nutrients.

Plant Cell Anatomy

• Cell wall: External supporting structure, rigid and primarily composed of cellulose.

• Primary and secondary walls: Plant cells have a primary wall and can often develop a secondary one.

• Middle lamella: The glue-like layer between cells.

• Plasmodesmata: Channels connecting neighboring cells, facilitating molecule transport.

• Plasma membrane (or plasmalema): Controls passage of materials into and out of the cell.

• Cytoplasm: Contents of the cell outside the nucleus.

• Organelles: Structures in the cytoplasm with specific functions.

• Cytosol: Fluid within cytoplasm.

• Nucleus: Contains genetic material.

Plant Cell Types

• Dermal Tissues: Cover the surfaces of plants, epidermal cells and trichomes.

• Ground Tissues: Inside dermal tissues—the palisade mesophyll and spongy mesophyll in leaves. They contain chloroplasts and other organelles.

• Vascular Tissues: Internal parts of the plant that facilitate transport, made of tracheids and vessel elements.

Cell Cycle Regulation and Development

• Cell Cycle Control: Strictly regulated by genetic control.

• Check Points: Key points in the cell cycle for regulation.

• Biochemical features of Cell Cycle: Each phase of the cell cycle has a specific set of biochemical and cellular activities.

• Cyclins and CDKs: Proteins driving cell cycle progression.

Plant Development: Cell Differentiation

• Totipotency: Early potential to differentiate into any type of cell.

• Pluripotency: The potential to give rise to many different cell types, though not all.

• Cell Differentiation: Development of diverse cell types.

• Morphogenesis: Biological process determining organismal shape and form based on cell arrangement.

• Cell Apoptosis: Programmed cell death, vital for development.