Plant growth
Plants, on the whole, continue to develop throughout their lives. Plants grow through cell division and growth. Cell division is also known as mitosis, as it multiplies the number of cells, whereas cell expansion expands the size of the cells. Plant cells specialise into several cell types as they grow through cellular differentiation. Once cells have differentiated, they can no longer divide.
The meristem is essential for plant cell growth and healing. A meristem is a form of plant tissue made up of undifferentiated cells that could proliferate and develop indefinitely.
Steps of plant growth
- When an egg cell fuses with a sperm cell, a zygote with a single cell is formed
- After this, a process known as embryogenesis takes place, which is simply the division of the zygote so that it becomes an embryo
- It leads to the creation of roots and shoots
- By the time the process of embryogenesis ends, the seed which is formed by the embryo would be ready to start its existence
- Through the process of organogenesis, once an embryo has germinated from its parent plant, it starts to create new organs (leaves, stems, and roots)
- New roots emerge from root meristems at the root’s tip, while new leaves and stems emerge from shoot meristems at the shoot’s tip
- When small clumps of cells left over from the meristem that have not yet experienced cellular differentiation to produce a specialised tissue continue to grow as the tip of a new root or shoot, this is known as branching
- Primary growth occurs when a meristem at the tip of a root, the shoot grows, resulting in the root or shoot extending
- Secondary growth is the enlargement of a root or shoot as a result of cell divisions in calcium
- A plant can also expand by cell elongation and cell division when individual or clusters of cells grow longer. All plant cells do not grow to the same size
Plant development
- Plant development is a multiphase process where two unique plant forms succeed in successive generations
- The sporophyte, for example, is a diploid form generated by the combination of gametes (sex cells)
- When the sporophyte reaches maturity, it produces haploid (single-chromosome) spores, which develop into the gametophyte generation
- The gametophytes create haploid sex cells when they reach sexual maturity, which combines to start a new cycle
- Plants and animals share the same chemical basis for inheritance and conversion of the genes to structural units known as proteins; however, plant growth differs from animal development in several ways. Animals, on one side, have a defined time of growth after which they are deemed mature; higher plants, on the other hand, continue to grow throughout their lives and are thus constantly embryonic
- All tracheophytes (vascular plants), bryophytes (mosses and liverworts), and many algae and fungi have a life cycle alternating between generations or various life phases
- Gametophytes are haploid, meaning that each cell has one set of chromosomes, and they develop from spores
- Sporophytes are diploid, meaning each cell includes two sets of chromosomes and develop from a fertilised egg, or zygote, that comes from the fusing of gametes created by gametophytes
Environmental conditions also influence plant growth and development. The qualitative and quantitative changes in growth caused by light, water, temperature, and nutrients are crucial for nursery and landscape management to be profitable. The limits and intensity of plant response are determined by the interaction of climatic conditions, physical and chemical responses, and genetic composition. Plants subjected to long-term water stress or malnourished may grow less vigorous and may produce aberrant leaves, blooms, or fruit. If a plant is exposed to environmental stress for even a brief period during a vital growth stage, it may never reach its full genetic potential. Each plant species’ viability and global dispersion are determined by its genetic and environmental interactions. This interaction provides the basis for the growth-promoting and growth-inhibitive cycles in a plant’s yearly life cycle.
Conclusion
Plant growth and development are equally important for the complete maturation of plants. “Growth” simply refers to “an increase in the size and mass of a plant over time,” whereas “development” is a more general term. “Development” is described as “the process by which a plant evolves from a single cell to a more complex multicellular plant.” On the one hand, growth is only concerned with the size or mass of the plant, whereas development is concerned with the structure, functions, and capacities of the plants. When a plant grows, it goes through the process of development, but solely in the sense of increasing its size and mass.