how do plants breathe?

Many living things require oxygen in order to complete vital processes, as this element plays a fundamental role in obtaining and processing energy. It is possible to obtain oxygen through respiration, but although the objective is similar, the processes are completely different depending on the species. In mammals, we associate breathing with lungs, nose and mouth, but plants have radically different specialised structures that allow them to obtain what they need from the environment.

It is fascinating to understand how plants work, what their needs and processes are. How they use water, the sun, how they feed, reproduce and breathe. Having a plant is like welcoming an alien into your home, getting to know them and learning how they live. Whether you have bought an air purifying plant or a plant that attracts good luck, if you have ever wondered how plants breathe, if they don't have lungs or noses, today at Be Green we explain the process in detail.

Plant respiration vs. photosynthesis

Some people confuse the processes of respiration and photosynthesis, but they are two different things. Plants breathe to obtain energy that allows them to carry out other life cycles. The absorption of oxygen allows them to use carbohydrate reserves to obtain this energy, expelling carbon dioxide and water vapour at the end of the process. From this perspective, respiration is considered to be the opposite process to photosynthesis, since in this process carbon dioxide is absorbed and oxygen is expelled.

It is important to mention that although plant respiration is a separate process from photosynthesis, they are intimately related; for in respiration the plant evaporates water, it dehydrates. If it does not get enough water from its substrate, the plant goes into water-saving mode and closes its stomata to prevent water from evaporating so quickly. This hinders photosynthesis, which is the plant's way of synthesising its food. Hence the importance of watering your plant correctly, without waterlogging the roots but so that it gets the water it needs to ensure its health.

where do plants breathe?

Plants breathe through their leaves. No, there are no tiny nostrils watering the leaves of your dwarf olive tree, but structures called stomata. Stomata are more like skin pores than nostrils, but they perform the function of gas exchange. Similar structures called lenticels are found on the trunks and stems of plants, but stomata are the most active in the respiration process.

Lenticels allow oxygen to pass through and water vapour to escape, but do not allow carbon dioxide to enter, so they do not participate in photosynthesis. On the other hand, stomata are multifunctional structures: they absorb and expel gases, so they are a fundamental part of 3 processes: photosynthesis, transpiration and cellular respiration.

when do plants breathe?

Stomata are structures with a heavy workload, so they must organise their time and functions. As photosynthesis always requires sunlight, it is most logical for the respiration process to occur at night. This division of labour is quite efficient, because with respiration they get the energy they will need the next day for photosynthesis. This does not mean that plants only breathe at night, but that it is a much more intense process at night. During the day the plant can breathe, not only through its leaves but also by using its roots, although it gets less oxygen than from its leaves.

You might be wondering how roots breathe if they are covered with soil, right? Well, it is very simple: they obtain oxygen from the water and the substrate, which acts as a vehicle for this gas. Hence the importance of maintaining an aerated substrate, suitable for the plant's needs, with proper drainage and allowing a decent level of oxygen.

The process of respiration and photosynthesis in plants is really fascinating, especially when you consider that much of our food comes from plants that are able to develop flowers, leaves and fruits from these processes. Indeed, it is possible to stimulate plant growth and flowering by manipulating the amount of light they receive by changing the concentration of certain nutrients in the substrate.