Botany

Botany is the scientific study of plant life. As a branch of biology, it is also sometimes referred to as plant science(s) or plant biology. Botany covers a wide range of scientific disciplines that study the growth, reproduction, metabolism, development, diseases, ecology, and evolution of plants.

Nearly all the food we eat comes (directly and indirectly) from plants like this American long grain rice.
Nearly all the food we eat comes (directly and indirectly) from plants like this American long grain rice.

Scope and importance of botany

As with other life forms in biology, plant life can be studied from different perspectives, from the molecular, genetic and biochemical level through organelles, cells, tissues, organs, individuals, plant populations, and communities of plants. At each of these levels a botanist might be concerned with the classification ( taxonomy), structure ( anatomy), or function ( physiology) of plant life.

Historically, botany covers all organisms that were not considered to be animals. Some of these "plant-like" organisms include fungi (studied in mycology), bacteria and viruses (studied in microbiology), and algae (studied in phycology). Most algae, fungi, and microbes are no longer considered to be in the plant kingdom. However, attention is still given to them by botanists, and bacteria, fungi, and algae are usually covered in introductory botany courses.

So why study plants? Plants are a fundamental part of life on earth. They generate the oxygen, food, fibres, fuel and medicine that allow higher life forms to exist. Plants also absorb carbon dioxide, a significant greenhouse gas, through photosynthesis. A good understanding of plants is crucial to the future of human societies as it allows us to:

  • Feed the world
  • Understand fundamental life processes
  • Utilise medicine and materials
  • Understand environmental changes

Feed the world

Virtually all of the food we eat comes from plants, either directly from staple foods and other fruit and vegetables, or indirectly through livestock, which rely on plants for fodder. In other words, plants are at the base of nearly all food chains, or what ecologists call the first trophic level. Understanding how plants produce the food we eat is therefore important to be able to feed the world and provide food security for future generations, for example through plant breeding. Not all plants are beneficial to humans, weeds are a considerable problem in agriculture and botany provides some of the basic science in order to understand how to minimise their impact. Ethnobotany is the study of this and other relationships between plants and people.

Gregor Mendel laid the foundations of genetics from his studies of plants.
Gregor Mendel laid the foundations of genetics from his studies of plants.

Understand fundamental life processes

Plants are convenient organisms in which fundamental life processes (like cell division and protein synthesis for example) can be studied, without the ethical dilemmas of studying animals or humans. The genetic laws of inheritance were discovered in this way by Gregor Mendel, who was studying the way pea shape is inherited. What Mendel learnt from studying plants has had far reaching benefits outside of botany. Additionally, Barbara McClintock discovered ' jumping genes' by studying maize. These are a few examples that demonstrate how botanical research has an ongoing relevance to the understanding of fundamental biological processes.

Utilise medicine and materials

Many of our medicinal and recreational drugs, like cannabis, caffeine, and nicotine come directly from the plant kingdom. Aspirin, which originally came from the bark of willow trees, is just one example. There may be many novel cures for diseases provided by plants, waiting to be discovered. Popular stimulants like coffee, chocolate, tobacco, and tea also come from plants. Most alcoholic beverages come from fermenting plants such as hops and grapes.

Plants also provide us with many natural materials, such as cotton, wood, paper, linen, vegetable oils, some types of rope, and rubber. The production of silk would not be possible without the cultivation of the mulberry plant. Sugarcane and other plants have recently been put to use as sources of biofuels, which are important alternatives to fossil fuels.

Understand environmental changes

Plants can also help us understand changes in on our environment in many ways.

  • Understanding habitat destruction and species extinction is dependent on an accurate and complete catalogue of plant systematics and taxonomy.
  • Plant responses to ultraviolet radiation can help us monitor problems like the ozone depletion.
  • Analysing pollen deposited by plants thousands or millions of years ago can help scientists to reconstruct past climates and predict future ones, an essential part of climate change research.
  • Recording and analysing the timing of plant life cycles are important parts of phenology used in climate-change research.
  • Lichens, which are sensitive to atmospheric conditions, have been extenisvely used as pollution indicators.

In many different ways, plants can act a bit like the ' miners canary', an early warning system alerting us to important changes in our environment. In addition to these practical and scientific reasons, plants are extremely valuable as recreation for millions of people who enjoy gardening, horticultural and culinary uses of plants every day.

History

Early botany (before 1945)

The traditional tools of a botanist.
The traditional tools of a botanist.

Among the earliest of botanical works, written around 300 B.C., are two large treatises by Theophrastus: On the History of Plants ( Historia Plantarum) and On the Causes of Plants. Together these books constitute the most important contribution to botanical science during antiquity and on into the Middle Ages. The Roman medical writer Dioscorides provides important evidence on Greek and Roman knowledge of medicinal plants.

In 1665, using an early microscope, Robert Hooke discovered cells in cork, a short time later in living plant tissue. The German Leonhart Fuchs, the Swiss Conrad von Gesner, and the British authors Nicholas Culpeper and John Gerard published herbals that gave information on the medicinal uses of plants.

Modern botany (since 1945)

A considerable amount of new knowledge today is being generated from studying model plants like Arabidopsis thaliana. This mustard weed was one of the first plants to have its genome sequenced. The sequencing of the rice genome and a large international research community have made rice the de facto cereal/ grass/ monocot model. Another grass species, Brachypodium distachyon is also emerging as an experimental model for understanding the genetic, cellular and molecular biology of temperate grasses. Other commercially important staple foods like wheat, maize, barley, rye, millet and soybean are also having their genomes sequenced. Some of these are challenging to sequence because they have more than two haploid (n) sets of chromosomes, a condition known as polyploidy, common in the plant kingdom. The "Green Yeast" Chlamydomonas reinhardtii (a single-celled, green alga) is another plant model organism that has been extensively studied and provided important insights into cell biology.