Overview

Description

CALENDAR DESCRIPTION:

The plant's physical environment and the physiological basis (mechanisms and principles) of the interaction between plants and their environment in relation to their survival and ecological distribution.

COURSE DETAILS:

Plant physiology, or how plants function, is often equated with photosynthesis, their ability to extract energy from sunlight to synthesize carbohydrates from carbon dioxide. This is not surprising since photosynthesis support the life not only plants but also all animal and most microbial life on earth. There is, however, so much more to plant physiology. For example, they take up water and minerals without pumps, they distribute carbohydrates and molecules such as hormones everywhere needed, also without pumps. How does that work? Plants are also often thought of as passive organisms, going on with their life program as much as the environment allows. They are nothing of the kind. They have a large range of molecules that sense for example changes in light intensity and quality and time of day, temperature and even touch. These inputs are constantly being integrated into short- and long-term responses, without a neural system. The response can also be extremely plastic. For example, the model plant arabidopis can decide to flower a few days after germination, generating a tiny plant with a few seeds, or it can go on to produce a plant a thousand times larger, with tens of thousands of seeds. They can also sense drought, heat, cold, and directly adjust to improve survival. Plants are also constantly under attack by microbes, insects and animals. Without efficient defenses they would go extinct. They use molecular recognition mechanisms to sense what microbe is attacking it and mount specific responses. In some cases, cells around the infection site are instructed to commit suicide to limit the spread of the pathogen. At the same time, signals are sent to the rest of the plant, so that they are ready when the pathogen spreads or the insects arrive. Plants also use a large range of chemicals sometimes to attract but mostly to poison attacking organism. For example, terpenes are toxic to microbes and insects, while alkaloids and cannabinoids have evolved to mess with mammalian brains. Ironically, many of these chemicals are used as perfumes, spices and drugs by humans. Here we will make sense of these hundreds of thousands of plant chemicals by separating them into just a few biosynthetic pathways. This course will also provide examples of how the study of plant physiology fits into the modern society by providing examples of its role in past and current plant breeding, adaptation to food shortages, climate change, and a future with plants as the major source not only of carbohydrates but also proteins.

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Materials

REQUIRED READING: