## The specific characteristics of plants

In relation to the environment in which plants exist, they have one major disadvantage compared to other organisms. They have a sessile way of life, which means they are fixed in one specific place and cannot leave in case of unfavourable conditions. Despite their sessile way of life, plants can spread, via seeds, from their original habitat over large distances. However, plants with a sessile way of life have evolved various sophisticated defence mechanisms to cope with the challenges of being located in one place. Thanks to these mechanisms, they can minimise damage caused by stress, maintain intracellular balance, and adapt at the cellular and molecular levels. The diversity of plant species allows us to observe how plants have adapted to various environmental conditions during evolution: Plants can be found in different environments, facing high or low temperatures, intense sunlight or lack of light, extreme weather conditions (strong winds, heavy snowfall), excess water, low atmospheric pressure, increased UV radiation or the presence of salts. In adapting to all these conditions during evolution, these changes are reflected in their genetic information.

Regarding the ability of plants to adapt to the environment, we have to look deeper into the structure of these organisms. Cells of all eukaryotes contain two types of genomes with different regulations - the nuclear and mitochondrial genomes (in the nuclei and mitochondria). Plant cells differ from other eukaryotes because they also have plastids, wich include chloroplasts which themselves contain a chloroplast genome. Due to the presence of the plastids, plants can react relatively flexibly to various stimuli from the external environment and adjust their structure and metabolic activity accordingly (for example, changing white etioplasts to green chloroplasts when exposed to light). All plastids originate from so-called proplastids and are generally divided into chloroplasts, chromoplasts, leucoplasts (amyloplasts, elaioplasts, and proteinoplasts), and etioplasts (Figure 11.1). Some types of plastids can repeatedly differentiate and transform from one type to another depending on environmental changes and the tissue in which they are located.