The course is aimed at providing the students the fundamental knowledge on the fundamental biochemical and physiological processes of higher plants, with the main objective of understanding the main mechanisms involved in the determination of crop plant yield, also in unfavourable environments. Such skills will be gained by means of frontal lessons and practical activities in the classroom concerning solving of biochemical problems and in the lab concerning the assay of biochemical compounds involved in the determination of the quality of agricultural produces.
Expected learning outcomes
Knowledge of the mechanisms regulating energy transfer and carbon metabolism in plants. Knowledge of the biochemical and physiological factors determining the productivity of crop plants, also in unfavourable environments. At the end of the course the gained knowledge will be useful to face practical issues in agricultural contexts, using also the augmented critical and judgment skills. Attending to classroom and lab practices, together with the type of assessment that foresees answering to one open question dealing with the main topic among those dealt with during the course, will contribute to the development of communication skills. Moreover, the use of diversified tools (textbooks, on-line material made available by the Teacher, personal notes, Internet) for the study will contribute to develop the ability to independently retrieve information useful also for future job activities.
Lesson period: Second semester
(In case of multiple editions, please check the period, as it may vary)
Principles of bioenergetics and thermodynamics. Thermodynamic systems and their environments. I and II thermodynamics laws. Enthropy and free energy. Exo- and endo-ergonic reactions; energetically coupled reactions. ATP and phosphor group transfer. Other high energy compounds. Carbon redox states in compounds of biological interest. Oxy-reduction potential. Relationship between delta E and delta G. Oxy-reduction coenzymes. Redox reactions of biological interest (0.5 CFU frontal lesson). Thermodynamic and kinetic aspects of enzymatic catalysis. Michaelis-Menten's equation. Inhibition and regulation of enzyme-catalyzed reactions (0.5 CFU frontal lesson). Metabolic reations: the concepts of catabolism and anabolism. Carbon metabolism: degradation of storage polysaccharides (starch). Glycolysis and lactic and alcoholic fermentation. Energy yield of anaerobic glucose degradation. The Krebs cycle. Electron flux and oxidative phosphorylation. Mitchell's chemiosmosis theory. Energy yield of glucose aerobic degradation. Other mechanisms of oxygen consumption in plants. Other pathways of glucose degradation: the pentose-P pathway. Basic aspects of the metabolism of storage lipids: energy yield of fatty acids degradation. Basic aspects of storage lipid degradation in plants: the glyoxylate cycle (0.8 CFU frontal lesson). Photosynthesis. The electromagnetic spectrum. Energy content of different wavelength radiations. Photosynthetically Active Radiation. Absorption and action spectra. Photosynthetic pigments: excitation and de-excitation phenomena. Photosystems, light-harvesting complexes, reaction centers. Energy transfer from the light-harvesting complexes to the reaction center. Accessory pigments. Photosynthetic electron flow and phosphorylation: the Z scheme. Non-cyclic and cyclic photophosphorylation. Herbicides disrupting the photosynthetic electron transport. Photooxidative damage. Carbon organication: C3 and C4 cycles, CAM metabolism. Photorespiration (0.8 CFU frontal lesson). Responses to light and temperature: light compensation point, CO2 compensation point (0.1 CFU). Plants and water. Definition of water potential and factors contributing to it in the plant cell: pressure, temperature, presence of solutes. Components of water potential in the plant cell: solute potential, matric potential, pressure potential. Osmotic phenomena: Van't Hoff's law. Isotonic, hypotonic, hypertonic solutions. Plasmolysis, cell turgor. Expansion growth. The soil-plant-atmosphere continuum. Water absorption by roots: the apoplastic and symplastic pathways. Transpiration. The driving force for the ascent of the xylem sap in the xylem. Loss of water through the stomata, regulation of stomata opening (0.85 CFU frontal lesson). Photosynthate translocation in the phloem. Osmotically generated pressure flow. Role of active transport of H+ in sucrose loading and unloading. "Sinks" and "sources" (0.85 CFU frontal lesson). Mineral nutrition. Plant nutrient requirements: micro- and macronutrients. Nutrient availability and plant growth. Solute transport in plant cells. Cell membranes and the plasmalemma: their role in cell physiology. Selective permeability. Chemical and electrochemical potentials and their role in determination of the direction of solute flux. Diffusion, active and passive transport. The Nernst's equation. Carriers and ion channels. Role of the PM H+-ATPase in generating the transmembrane electrochemical proton gradient and its role in secondary active transport. Absorption and assimilation of N, S and P. Micronutrient absorption: the case of Fe. Heavy metal toxicity: the case of Al. Mechanism of resistance to heavy metals: exclusion and detoxification (1 CFU frontal lesson). Plant growth regulators. General description of their peculiar characteristics. Evaluation of biological activity: biological tests. Auxins, gibberellins, cytokinins, abscisic acid and ethylene: description of a few specifici physiological effects and of a few related agricultural practices. Stress physiology. The concepts of stress. Abiotic stresses: low temperature stress, water stress, soil acidity stress, oxidative and radiation stresses. Biochemical and physiological aspects of plant responses to stresses (0.35 CFU frontal lesson). Specific topics will be broadened by exercises in the classroom.
Prerequisites for admission
Full understanding of the Course contents is strictly dependent on the knowledge, from previous Courses, of fundamentals of Plant Biology, Physics, Inorganic Chemistry and Organic Chemistry. Such prerequisites apply to all students, both attending the Course and not.
The Course uses e-learning teaching tools present in the Ariel 2.0 platform (Power Point slides, video recordings of the lectures). The Teacher will use: a) frontal lessons; b) classroom practices; c) laboratory practices. All the activities will contribute to gaining the Expected Learning Outcomes. Attending the lectures is strongly recommended.
Nelson D., Cox M. "Introduzione alla biochimica di Lehninger", ed. Zanichelli (first half of the Course, Biochemistry). R. Pinton et al., Fondamenti di Biochimica Agraria, Patron Editore, Bologna. D'Andrea G. Biochimica Essenziale EdiSES (first half of the Course, Biochemistry). N. Rascio, "Elementi di Fisiologia Vegetale", Edises (second half of the Course, Plant Physiology). R.F. Evert, S.E. Eichhorn, Biologia delle piante di Raven, Zanichelli (first and second half of the Course, Biochemistry and Plant Physiology). Notes from the course lectures. Copy of the slides shown during the lectures will be made available to the students of the Degree Course in the UniMi Ariel 2.0 website (Biochimica e Fisiologia Vegetale) by the Teacher. In the same website students will also find video recording of all the lessons. Bibliography is the same for both attending- and non-attending students.
Assessement methods and criteria
None compulsory prerequisite. Nevertheless, the successful getting through of the First Year (Plant Biology, Physics, Inorganic Chemistry and Organic Chemistry) is strongly recommended prior to start the study of the topics inherent to the exam. The exam will consist in two written tests (in two different dates), one concerning the first part of the Course (Plant Biochemistry), the other one concerning the second part (Plant Physiology). An "in itinere" test is foreseen, shortly after the first half of the Course. During the exam it will be allowed THE ONLY aid of a personal portable calculator (NOT the one of the smartphone!). The Biochemistry test is made up by one open-ended questions (0-9/30) plus 24 multiple choice questions (0,75/30 each if correct, 0/30 if missing and -0,25/30 if uncorrect) plus one exercise (0-3/30). The exercise is addressed to problems typicals of biochemistry laboratory. The Plant Physiology test, which may be tackled only in case of positive result in the Biochemistry test, will be made up by one open-ended questions (0-9/30) plus 28 multiple choice questions (0,75/30 each if correct, 0/30 if missing and -0,25/30 if uncorrect). Open-ended questions will be evaluated on the basis of parameters like ability to organize and explain the gained knowledge, quality of written text, competence in the use of specialized language, etc.).The exam as a whole will be considered passed provided that the results are positive (score equal to or higher than 17.5/30) in both tests. In case of a score of less than 15/30, it will not be allowed to repeat the test before 30 days. Assessment modes will be the same for both attending- and non-attending students. The results will be posted at the notice board at the seat of the Study Course (Edolo) and at that of the dedicated Ariel 2.0 site. The exams will take place at Edolo with a minimum number of students equal to 5; otherwise, the exams will take place at the Facoltà di Scienze Agrarie ed Alimentari, via Celoria 2, Milano. Students with Specific Learning Disorders: in order to take advantage of the foreseen facilities, students should make aware the dedicated Office at UniMI (Serv.Interventi Assistenza,Integrazione Sociale,Diritti Persone Handicap; http://www.unimi.it/studenti/serviziodisabiliedsa.htm. Prof. Raffaella Zanchi (firstname.lastname@example.org) is the reference person at the Faculty. The Teacher should also be made aware, in due advance, of specific situations for agreement on exam modalities. Students enrolled to an exam but unwilling to stand the test should in due time communicate their decision to prof. the Teacher. If not, they will not be admitted to the test in the successive date. On the basis of specific and proven requirements of Off Course students, additional test dates may be planned after appointment with the Teacher at the Faculty of Agriculture in Milan.