How plants got their thorns: A genetic mystery solved
Thorns in different plant species have always been an interesting subject for botanists. Be it rose plants or cactus, they use thorns to protect themselves from herbivorous animals. It was long unknown to researchers about the genetic development of thorns in plants. This has been clarified recently through the discovery of how genetic mutations can cause regular plant cells to become thorns. Through the study of genetic regulation in plant development, it is now becoming clear how thorns evolved over time through natural selection.
The genetic basis of thorn development in plants
Some of the greatest discoveries in thorn research relate to the study of the way in which certain genes influence the plant anatomy. Thorns are revealed to be a kind of reorganisation of already existing organs rather than a complete novelty of plant structure. As the study ‘Developmental study of thorns in tissue culture clone of Lycium ruthenicum’ reveals:“Thorns, spines and prickles develop by modification of genetic programs that would otherwise produce shoots or leaves.”In other words, instead of being an evolution of plant structures, thorns are actually a case of redirection of the development program. The genetic regulators that contribute to plant structure formation and development in general, specifically meristem genes, are the key. The way these genes are turned off and on determines whether a plant develops hard parts or soft tissues.There is also an additional layer of genetic regulation that controls the timing and location of thorn growth.
Evolutionary advantages of thorns in plants
In terms of evolution, there is certainly an advantage to having thorns in plants. Those plants that managed to develop protection from animal grazing would be able to survive and reproduce, passing on their genes.‘A review of the types, functions and regulatory mechanisms of plant spines’ states:“Defensive structures like thorns have evolved repeatedly across various groups of plants, emphasising their importance in protecting from herbivores.”It is worth mentioning that thorns have evolved separately in several plant families. This process is referred to as convergent evolution, which means that certain environmental factors led to the separate evolution of thorns. To put it another way, in similar environments, thorns can evolve separately because of animal grazing.In addition to protection from herbivorous animals, thorns can play other roles. For example, in arid habitats, thorns can reduce water loss by providing shade. In cacti, spines are essentially thorns that serve two functions.
Modern research and future implications
Advances in technology have enabled scientists to explore genes at the genetic level. Comparing the genomes of thorny and thornless plants, one can establish genetic differences and find out why some plants produce thorns while others don’t.Specialised structures in plants, more often than mutations or gene novelties, cause modifications in gene expression patterns and contribute to the development of certain characteristics.Such a discovery can significantly influence modern agriculture. If specialists get the ability to understand how plants control their characteristics, they will be able to create plants that are less susceptible to various pests and therefore do not need any artificial means of protecting them from insects. Moreover, people can breed plants such as roses without thorns but with their natural protection against pests and other potential dangers.In addition to understanding how plants develop, the above information shows an interesting fact about evolution. Evolution does not necessarily mean creating new mechanisms, as demonstrated by the development of thorns.It turns out that the question of how plants acquired thorns can finally be answered. Thanks to scientific research in genetics, it has been found that thorns are formed because plants develop different paths of their growth due to changes in gene expression.
