Development — Definition
Definition
Imagine a tiny seed. It's small, dormant, and doesn't look like much. But given the right conditions, it sprouts, grows into a seedling, then a mature plant with leaves, stems, roots, flowers, and eventually fruits. This entire journey, from a single-celled zygote (formed after fertilization) or a seed to a complex, fully functional adult plant, is what we call 'development'. It's not just about getting bigger (that's growth), but also about becoming specialized and organized.
Think of it like building a house. Growth is like adding more bricks, making the house larger. Development, however, is the whole process: laying the foundation, building walls, installing plumbing, wiring electricity, painting, and furnishing – each step making the house more complex and functional.
Similarly, in a plant, cells don't just multiply; they also change their form and function. Some become root cells, specialized for water absorption. Others become leaf cells, designed for photosynthesis.
Still others form the vascular tissue, acting as the plant's transport system. This process of cells becoming specialized is called 'differentiation'.
Development is a highly regulated process. It's like a carefully orchestrated symphony, where various internal cues (like the plant's genes and special chemical messengers called Plant Growth Regulators or PGRs) and external signals (like sunlight, temperature, water availability, and nutrients) work together.
These factors dictate when a seed should germinate, when leaves should form, when flowers should bloom, and when fruits should ripen. A fascinating aspect of plant development is 'plasticity', which means plants can change their developmental pathway in response to their environment.
For example, the shape of leaves on the same plant might differ depending on whether they grew in water or air. So, in essence, plant development is the holistic, irreversible progression of an organism from a simpler to a more complex, organized, and functional state, driven by a dynamic interplay of genetic programming and environmental influences.