When we hear the word “genomics,” many of us perceive it as something distant, complex, hard to grasp, and perhaps very far from our daily lives. However, nothing could be further from the truth! The genome of a being is simply like a vast library. In it, we find books covering all the topics that encompass our understanding and relationship with the world. The books are always the same, and yet, just as in a library, we don’t read all the books at once. Similarly, living beings don’t use all the information all the time; it’s simply there and available, and the books we choose to take out of the library are the ones that interest us at that moment. So, just as if we see someone taking out books on, for example, “bioclimatic construction,” we understand that at that moment, that person is engaging in things related to this topic. Similarly, by studying the expressed genes, we can get an idea of the situations the organism is facing at each moment and how it will respond to them.
The “library” of broccoli tells us many things; it provides information about its growth, development, and interaction with the world. Understanding these genes allows us to know if a variety has the ability to produce different beneficial compounds, for example. But not only that, by studying gene expression, we can understand how and when they do it. Broccoli protects itself from the cold, faces water scarcity, nutrient deficiencies, salinity, and all of this affects its size and, more importantly, its final quality. The final quality, from a human perspective, depends on the accumulation of compounds beneficial to our health, and these compounds are produced in reaction to a specific environment.
Obviously, there will be a large set of common “books” in all broccoli “libraries” because broccoli plants have adapted over their evolution to the environment in which they grew. Broccoli is a plant native to countries along the Mediterranean, in the Near East. It is important to understand that the temperate climates of the Mediterranean are ideal for these plants. However, this climate includes periods where temperatures drop to around 10º during the day, and nighttime temperatures plummet, causing intense frosts. Thus, broccoli is a plant that withstands the cold of the Mediterranean winter very well, and today it is mainly a crop of autumn-winter thanks to the many “books” in its library that allow it to protect itself from the cold. But what other “books” does the cold take out of the library?
From this point of view, one of the great advances in genomic studies of broccoli has been to find that each variety of broccoli uses different “books” to respond to the same situations. What causes these differences? To get an idea of how it works, if a plant is native to a desert, it will learn to use the few moments of rain to accumulate as much water as possible to keep functioning during long periods of extreme drought. This will be the case from the beginning, but each plant is slightly different from the others; the books in the library are not exactly the same in each individual. Thus, if we take them to an environment of constant rain, on the one hand, they will not spend energy improving their ability to store water, as it will no longer be a problem for their survival; those “books” will no longer be useful. However, they will probably have to learn to defend themselves, for example, from the appearance of fungi, as these are more common and abundant in humid environments. Thus, these plants will start to “take out books” on compounds that repel those fungi, and some will do it better than others, each one will look in its library for the most appropriate books. This is exactly what has happened with broccoli varieties and is what makes it possible for us to have broccoli on the table almost all year round, thanks to the selection of varieties that are most suitable for each climate and soil based on their genetic response. As a specific example related to the cold, some broccoli varieties use “spending” strategies, something like, while there are resources at hand and good conditions, make the most of them, a kind of “carpe diem!” These varieties will be suitable for areas with short, mild winters, with more influence from the sea as a temperature regulator, while other varieties are more conservative, take longer to grow, but their ability to remain unaffected by changing environmental conditions allows them to survive and come to term even in very adverse and prolonged conditions. These latter ones will be favorable to grow in areas where the climate is more continental, with longer and colder winters. But in addition to the strategy they adopt according to the climate, varieties will take out “books” on certain compounds that help in that environment, as each area has an entire surrounding ecosystem, including pathogens, herbivores, or beneficial organisms, which will be attracted or repelled.
Understanding the genetics of broccoli leads us to know where and when to plant each variety, understand their specific nutritional needs and when they should be applied, and even more, it allows us to know what conditions favor the production of vitamins such as B1, E, A, or C, the accumulation of minerals such as calcium, zinc, iodine, iron, or magnesium, or compounds that are increasingly important in disease prevention, such as glucosinolates and isothiocyanates. Understanding that the accumulation of these compounds depends on the “books” they take out of the library and that they always occur under specific conditions—what could we not achieve?
Applying this knowledge, we can achieve “customized broccoli” selected for each area based on the terrain, water, climate, ecosystem, and even more, adapted to the nutritional needs of the people who consume them, reducing nutritional deficiencies in entire populations, improving health, and helping to fight against diseases, all thanks to the knowledge of genomics. Doesn’t it seem so distant anymore?
Gloria Bárzana González
Researcher
