Marijuana plants are complex living organisms. Human eyes see only the roots, stems, leaves and flowers. But if you zoom in, right down to the microscopic level, you’ll see millions of cells working together in amazing complexity, busy with the countless functions and processes that help the plant thrive and, ultimately, reproduce.
As a marijuana grower, it’s in your best interest to learn the basics of plant biology. After all, each time you tinker with light, heat, air, water and nutrients, you affect the plants at the cellular level. Whatever you do, no matter how trivial, will impact the plant. From opening the tent (and flooding it with light) during the dark hours, to missing a watering, to simple pruning – it all evokes a cellular response.
Once you understand the inner workings of cannabis plants, you’ll have a clearer picture of what they need. This will be of enormous help when tweaking growing conditions and observing the plants. The more in tune you become, the easier it will be to grow healthy, robust plants with heavyweight yields.
What are marijuana plants made of?
All living organisms consist of cells. Cannabis roots, vascular systems, stems, leaves and buds have several types of cells, each with specific functions. They work in tandem to perform various tasks.
A single cell is constantly jiggling and jostling with activity. It’s like a soft-play factory, with squishy workers and gelatinous machines constantly processing raw materials into new things… making, moving and synthesizing. It is hugely complex and very, very busy. But let’s take a look at the basic parts.
The exterior of cannabis plant cells – the cell wall – is a tough outer layer that gives it shape, strength and structural integrity, shielding the cell from mechanical stress. It’s composed of cellulose, hemicellulose, lignin, and pectin, as well as some proteins and polysaccharides.
The cell wall regulates what goes in and out of the cell. Water, oxygen and carbon dioxide can easily pass through. Large, damaging molecules, on the other hand, are barred entry.
This ensures the cell is well-hydrated, but not to the point of bursting. The right amount of moisture strengthens the cell walls, which, in turn, helps the plants fend off pathogens and other harmful elements. Simply put, fortifying the cell walls allows you to grow more resilient marijuana plants.
Keep the light and heat levels within optimal levels at all times. When you stray outside acceptable parameters, the cell walls can elongate and weaken, meaning reduced growth and yields.
The cell or plasma membrane is a thin, semi-permeable layer found between the cell wall and the cytoplasm. It’s composed of proteins and fats. While less rigid than the cell wall, it also helps reinforce the cell with structural support.
The membranes serve as extra protection against the outside environment, letting in nutrients and essentials while expelling/repelling any toxins. In some cases, particles will force their way through the cell wall – only to be ejected by the membrane. A powerful second line of defense.
Cytoplasm is the gel-like fluid within the cell membrane. It primarily consists of water but also contains enzymes, salts and organic molecules. It holds the organelles in place and helps maintain the shape of the cannabis plant cell. Protein synthesis, glycolysis, cell division and other cellular activities occur within the cytoplasm.
Plant cells contain many organelles, each with specific functions. These smaller structures perform a wide range of tasks – from producing hormones to capturing and generating energy.
Plastids are a group of double-membrane organelles involved in an array of processes. They play a significant role in photosynthesis, food storage and the synthesis of molecules that form the building blocks of the cells. They also contain the pigments that give cannabis plants their distinct colors.
Chloroplasts. These plastids contain chlorophyll – the green-colored pigment in charge of photosynthesis. Chlorophyll captures light energy and uses it to turn carbon dioxide and water into carbohydrates.
Chromoplasts. These plastids produce and store yellow, orange and red pigments.
Leucoplasts. These plastids are colorless, non-photosynthetic organelles used for the storage of starch, lipids and proteins. They help with the synthesis of fatty acids, amino acids and other compounds.
Mitochondria are the batteries of the cell and can be thought of as the powerplant of the entire cannabis plant. They’re primarily responsible for converting carbohydrates and sugar molecules into adenosine triphosphate (ATP) in a process called respiration. The ATP molecules, in turn, provide plants the energy they need for growth, survival and other functions, including the production of buds and trichomes.
Without enough light and heat, mitochondria cannot generate energy, causing the plants to wither and die. Excessive light and heat is just as detrimental, resulting in bleaching, wilting and other symptoms of light burn. Powerful bulbs like MH and HPS lights, when positioned too close to the upper canopy, can cause this problem.
Oxygen is also a key element in respiration. Overwatering your marijuana plants will deprive the roots of oxygen. The root tissues will start to decay, ultimately leading to stunted growth and low yields. Persistent overwatering will kill the plants.
In mature marijuana plant cells, the central vacuole makes up over 30 percent of the cell’s total volume. In some cases, it can be as high as 90 percent. The vacuole is filled with cell sap – a solution containing salts, ions, enzymes and other substances – and is enclosed by a single membrane called the tonoplast. The central vacuole has many responsibilities.
- The central vacuole acts as a storage compartment, collecting leftover nutrients and food which the plants can later use to support growth and bud production.
- A dumpsite, holding onto waste and toxins until they are ejected from the plant. This not only keeps the reservoir contaminant-free, but it protects the plants from predators.
- Aside from storage, the vacuole also helps maintain turgor pressure by pushing the cytoplasm against the plasma membrane. It keeps the cells firm, allowing them to hold their shape and structure, resulting in more robust marijuana plants.
Without enough water, the central vacuole becomes dehydrated. As it loses its tightly-packed structure, the entire plant starts to wilt. Having good watering practices can help avoid this problem.
The endoplasmic reticulum (ER) is a complex network of flattened sacs. It is made up of two major regions – the rough ER (with ribosomes) and the smooth ER (without ribosomes).
The ER synthesizes, processes and transports proteins and lipids or fats. When marijuana plants get stressed out due to unfavorable growing conditions, the ER can break down, impairing its ability to process and modify proteins and fats. As a result, the cell walls may weaken, causing the mitochondria to struggle with respiration.
Ribosomes, the smallest membrane-bound organelles in a plant cell, consist of RNA and proteins and can be found either floating freely in the cytoplasm or attached to the rough ER.
They are in charge of protein synthesis – a process in which amino acids are used as building blocks to form proteins. For this reason, ribosomes are sometimes referred to as the protein factories of the cell.
The Golgi apparatus – also referred to as the Golgi complex – has been dubbed as the cell’s post office. After modifying the proteins and fats made in the ER, it stores, packages and prepares them for distribution outside of the cell.
The nucleus is a membrane-bound structure that can be likened to an information center. It contains the cannabis plant cell’s hereditary material or DNA, which dictates the unique qualities of a particular strain.
The nucleus also serves as a command center. It coordinates the activities of the cell, including growth, metabolism, protein synthesis and cell division or reproduction.
Knowledge is power
It doesn’t take a rocket scientist to grow marijuana. Modern hybrids are far easier to cultivate than the strains created decades ago. This is because the best breeders and seed banks continuously improve genetics, resilience, disease-resistance and vigor. Understanding your plants at a cellular level means a deeper understanding overall, and can only help in your journey to becoming an expert grower of marijuana. More knowledge, better plants – you’re on your way!