1BSCI 442, Plant Physiology• Why study plants?• What are plants?• What is plant physiology?• Goals of the course• Introductions• Organization of the courseLife on earth depends on plants•Primary producers: Green plants provide the world’s supply of food. •Plants provide the world’s supply of O2in the atmosphere.•Plant diversity is essential to the survival of biotic communities.Life with plants Cont.•Plants provide fiber e.g. cotton, flax –linen, paper, cardboard.•Plants provide medicine•Plants generate energyWhat are plants?•The only eukaryotic organism that can make their own food.•Non-motile.Plants come in all shapes and sizesChara, Chlamydomonas, Pitcher plant, Giant SequoiaMoss, fern (Marsilea), cycas, pine2Seed plants are the most successful land plants1. Gymnosperms (naked seeds)2. Angiosperms or flowering plants (contained seed)Why?Most advanced and dominant, because of their reproductive features.•Embryo is protected and can survive harsh environment•Fertilization does not depend on water. Pollen and seeds are dispersed by wind or insect.•Plants have developed vascular tissues, so they can survive on land and reach great heights.The "six" kingdom taxonomic scheme. Image from Purves et al., Life: The Science of Biology, 4th Edition3 kingdoms of organisms : Bacteria, Archaea, Eukaryakelpanimalsplantsfungichloro-phytechryso-phytechoanoflagellateslimemoldred algaegreen algaeunicellularmulticeullularcomplexmulticeullularbrown algaecilliate“macro”-eukaryotes“micro”-eukaryotesrhodo-phyteLCEAcyano-bacteriaδ-proteo-bacteriaredalgaeSL-163 Choanoflagellate, D. Moranwww.ucmp.berkeley.edu/protist a/rhodophyta.htmltepserver.ucsd.edu/~eshep ard/underwater.html© 2005 Marine Discovery Tom Cox www.etsu.edu/©BIODIDACThe Freshwater Algal Floraof the British Isles© 1997 Ohio Public Library Information Network www.nies.go.jpNational Human Genome Research Insti tutewww.biol.tsukuba.ac.jpNational Human Genome Research Insti tuteoceanexplorer.noaa.govSanderfoot A. (U Minn) 2006The fossil records of some protist and plant groups. The width of the shaded space is an indicator of the number of species. Image from Purveset al., Life: The Science of Biology, 4th Ed.450 m200 m600 m65 mFossil records indicate that higher plants evolved from algaePhylogenetic reconstruction of the possible relationships between plant groups and their green algal ancestor. Note this drawing proposes a green algal group, the Charophytes, as possible ancestors for the plants. Image from Purves et al., Life: The Science of Biology, 4th EditionPlants are convenient organisms to study fundamental processes in biology• Genetics• Cell Biology: mitosis• Physiology: How do plants sense and respond to the environment?3What is Plant Physiology?Study of how plants grow, develop and adapt and why plants behave in a particular way.Goal: to understand a process from the whole plant to the cell,molecular and genetic level.•How do plants that cannot move get their essential 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?Picture taken from: Boyes et al. 2001. Plant CellLife of a land plantThe first complete genome of a model plant was sequenced in 2000.Nature 408, 796-815 (14 December 2000) | doi: 10.1038/35048692Analysis of the genome sequence of the flowering plant Arabidopsis thalianaThe Arabidopsis Genome InitiativeThe genome contains 30,700 genes encoding proteins from 11,000 families, similar to the functional diversity of Drosophila and Caenorhabditis elegans— the other sequenced multicellular eukaryotes. This is the first complete genome sequence of a plant .Understand Living Processes at the Physical, Chemical, Molecular & Genetic LevelPlantLeafCellOrganelleMolecules: e.g. enzymesGeneWhy?Better understanding of plant biology will prepare one to face many challenges1. Major challenges •Feed a world population •Agriculture: develop crops that are disease-resistant and stress-tolerant.•Health: produce medicines and improve nutritional value•Environment: Preserve plant diversity which is essential for the survival of all living organisms.•Provide energy2. Plant biotechnology is one way to address these challenges. We need technical and scientific information to understand andevaluate the potential of this new technology.3. Our health & choicesShop and prepare food health supplements4Goals of the Course• To understand how plants grow, develop, reproduce and survive. • To better understand basic concepts and life processes of all organisms• To gain a working knowledge of biology so one can make educated decisions and judgements in one’s professional and personal life.• To stimulate and promote independent