Growth and development in plants will always be affected by some internal and external factors. Both factors decide the life span of some plants, even.
- Hormones, in this specific instance, growth hormone is called phytohormone. Types of hormones in plants vary a lot, such as gibberellins for seed germination, cytokinins for bloom stimulator, auxins for cell elongation, rhizokalins for root formation, abscissa acids for leaves abscission, ethylene for fruit maturation/ripening, etc. In plant’s growth, one or several combinations of hormones can affect some parts of its growth, for example gibberellins and cytokinins can stimulate seed germination and also affect growth in meristemic areas so that the amount, mass, and volume of living cells keep growing.
- Enzymes, they are chemical components in the shape of functional and structural proteins that are obtained through protein synthesis by living cells. Enzymes are very important for growth and development. Because of their specific functions, several types of enzymes will affect metabolism and biochemical reactions in plants.
- Genes, genes bring about genetic codes in the form of triple nitrogen base, sugar cluster, and phosphate cluster. Inside genes, there are nucleate acids in the form of DNA and RNA. Genes affect plants’ growth and development because without genes, it is impossible to have any cell activity undergo well enough because genes are produced in nucleus for eukaryotic living things.
External Factors (Environmental)
- Water. Water functions as natural solvent for hormones, enzymes, nutrients, and other components. In the metabolism process, water is very needed to do photosynthesis that is resulting in food in the form of glucose that will then be distributed through phloem in leaves’ mesophyll.
- Humidity. Low humidity factors in accelerated growth and development while the opposite is also true. This is why seed germination needs to happen in low humidity.
- Soil. Soil is also a deciding factor in plants’ growth and development process. Soil is the planting medium that provides a lot of non-essential nutrients, the prop where plants’ roots can stick perfectly and for plants to stand upright and sturdy, the provider of water and other non-physical components like organic and non-organic material, mineral salt, and other nutrients needed for growth and development.
- Light. Light is very important for plants. In low light condition (dark room), plants’ growth process is accelerated and it can cause etiolation with characteristics like tall, thin stems with pale leaves. In high or enough light condition, the growth process will be slower but with more ideal stems and leaves. This is caused by auxin hormone that’s light sensitive, in which it dies when exposed to light. Moreover, high intensity sun light can destroy plants’ enzymes, but plants will still keep their physiology so they can grow as well as possible.
- Weather and climate. Weather and climate take important roles in plants’ growth and development. Extreme and dangerous weather can put a hamper on seed germination and seedling growth. Changing weather, anomaly, also affects plants’ physical condition. Climate also has an important in what kind of plants can grow in certain climates. For example, coconut trees won’t grow in the South Pole with cold climate, instead on tropical climate like in Indonesia.
- Temperature. Temperature plays an important factor in plants’ growth and development. In 0 degree celcius, enzymes won’t work optimally so you will have to up the temperature by several degrees. However, too high of a temperature will cause enzymes to denaturate because their prosthetic clusters are destroyed. This usually happens in temperature higher than 56 degree celcius.
- Nutrients. Nutrients that are provided by the soil like mineral salt and water are important for growth and development. You can also add extra nutrients by using organic and non-organic fertilizer. Fertilizers can give your plants extra nutrients like zinc, magnesium, potassium, calcium, molybdenum, iron, nitrogen, etc. Be careful when adding fertilizer and make sure you’re adding the right dosage for your plants.
I hope this explanation about internal and external factors affecting Plant Growth and Development, is what you’re looking for. Happy gardening!