BSCI 442 Introduction to Course

Why study plants? Why are plants important?

Green plants provide the world’s supply of food.
Plants provide the world’s supply of O2 in the atmosphere.
Plant diversity is essential to the survival of biotic communities.
Plants provide fiber e.g. cotton, flax –linen, paper, cardboard.
Plants provide medicine.
Plant products are a source of energy.

What are plants?

Diversity: Plants come in all shapes and sizes. The plant kingdom includes unicellular alga to giant trees. Land plants evolved from ocean dwelling alga-like ancestors.

Algae
        Green Algae Chlorella unicellular; Chara -ancestor of land plants
        Brown Algae Laminaria, Kelp
        Red algae      Rhodynemia palmata, Unicellular Porphyridium

Early land plants-mosses, liverworts, hornworts, ferns.
                Moss: gametophyte and sporophyte
                             Small plants, no true roots, no leaves
                             No vascular tissue,
                             Cannot grow to great heights.
                             Fertilization depends on water.
                Ferns are the exception: have vascular system, can be small trees

Seed plants: most successful land plants
     Gymnosperms (naked seeds)
            Ginkgo, leaves and fruit
            Redwood Sequioa in Calif.
    Angiosperms or Flowering Plants (contained seed)
           Monocot e.g. corn
           Dicot   e.g. bean

Most advanced, most dominant, because of its reproductive features.
Embryo is protected, and can survive harsh environment
Seed dispersal by wind and insect, [fertilization does not depend on water]
Developed vascular tissues and supporting wood tissue, so plants can reach great heights.

All living organisms are related to one another.
All life on earth evolved from a common single cell ancestor. Plants are convenient models to discover and to study fundamental processes in biology.

What is Plant Physiology?
It is the study of how plants function in order to grow, develop, survive and reproduce, and why plants behave in a particular way.
Therefore we ask questions like:

How do plants that cannot move obtain their nutrients?

How do plants convert solar energy to food (chemical) energy?
How do plants survive harsh winters or summers?
How do plants respond to stimuli from hormones or from the environment?
How do plants reproduce, protect and nourish their young?
How do plants ward off disease-causing microbes? or develop defenses?
What regulates all these processes?

Plant physiology is one of the most important and exciting areas in plant biology. Physiologists, biochemists, molecular biologists and geneticists want to understand these complex living processes at the biochemical and molecular level. When we understand how plants work, the scientific knowledge can be directly applied to benefit agriculture and the environment.
e.g. incr. productivity, enhance disease resistance, obtain crop plants or turf grasses that are herbicide resistance, enhance nutrional value of seed oils, use plants for medicinal purposes.

Plant biotechnology is the use and manipulation of plants or substances obtained from plants to make products of value to humanity.

Significance/ relevance
1. Major challenges

Feed a world population
Deliver Natural Products Needed By Industry and for Medical Purposes
Preserve plant diversity which is essential for the survival of biotic communities

2. Plant biotechnology is one way to address these challenges

3. We need technical and scientific information to understand and evaluate the potential of this new technology.

Goals of the Course

a. To understand how plants live, grow, reproduce and adapt.

b. To assimilate basic concepts and knowledge in order to make educated decisions in one’s future professional and personal life.

c. To stimulate and promote independent thinking.

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Major Stages in the Life of a Plant

    1. Seed Germination
    2. Development of the plant body
    3. Development of the reproductive organs
    4. Seed Formation

Reference: BSCI 124: see http://www.life.umd.edu/classroom/BSCI124/main.html