18756 - Biology of Plant Development

Learning outcomes

At the end of the course, the student will have acquired a deeper knowledge, especially at the molecular level, of plant cell biology and of the control of developmental processes (embryo, shoot, root, and flower development) in Angiosperms. The student will become familiar with the main methods used to study these topics and will be able to critically read and interpret scientific publications dealing with all aspects of plant biology.

Course contents

The main research topics in plant biology. A brief review of the classical techniques (microscopy, microsurgery, treatment with exogenous hormones and other factors) used in plant biology. Model plants (Arabidopsis, tobacco, Zinnia, Antirrhinum, etc). Advanced techniques in plant biology: mutants (deficient, over-producing or insensitive to phytohormones, developmental, etc), chimeras, RNA interference, genetic transformation (over-expression, ectopic expression, antisense strategy). Methods for genetically transforming plants : floral dip, particle gun and Agrobacterium as a vector; use of transgenic plants for basic research. Use of fluorescence (GFP), in situ hybridization and reporter genes (GUS). In vitro cell and organ cultures: methods and applications.

The cell cycle: factors controlling cell cycle progression (CDKs, cyclins); the influence of internal (developmental) and external (biotic and abiotic stress) factors. Endoreduplication and positional information in differentiation (the example of leaf trichomes). Plasmodesmata: structure and functions. The cytoskeleton in plant cells: structure and functions. Methods for measuring changes in cellular calcium levels (imaging, cells transformed with aequorin). Apical growth in pollen tubes: the role of the cytoskeleton, vesicle trafficking and calcium gradients; signalling pathways (e.g., GTPases). Genetic control of the differentiation and localization of stomata; the signalling cascade leading to changes in guard cell turgour pressure.

Plant hormones: categories, functions, specificity, methods for studying hormone functions, perception and signal transduction (receptors, one/two-component systems, G proteins, MAP kinases, endosome-mediated signalling, calcium signature, calcium-dependent kinases). Examples: ABA/stomatal guard cells and cytokinins/cell cycle.

Introduction to plant development (coordination, environmental cues, autonomy of single parts, indefinite growth, totipotency). Meristems: types, localization, functions, zonation, cell identities, positional information, transcriptional control. Embryogenesis: stages, orientation of cell division, factors regulating polarity, mutants, genes and transcription factors (Auxin Response Factors, Aux/IAA, SHOOT MERISTEMLESS, etc); apomixis and in vitro somatic embryogenesis (genes, chemical signals). The shoot apical meristem: functions, organization at the cellular and transcript levels; genetic control (WUS, CLV, STM), organogenesis, phyllotaxis and the role of auxin and PIN auxin transporters; leaf development. The root apical meristem and root development: the quiescent centre, root hair differentiation (positional information and genes), mutants of root development (scarecrow, short-root, monopteros, bodenlos, etc.), the role of auxins and cytokinins in lateral root and adventitious root formation. Floral transition and flower development (ABC model).

Readings/Bibliography

Altamura, Biondi, Colombo, Guzzo – Elementi di Biologia dello Sviluppo delle Piante (EdiSES)

Buchanan et al. - Biochimica e Biologia Molecolare delle Piante (Zanichelli)

Davies P.J. – Plant Hormones. Biosynthesis, Signal Transduction, Action (Kluwer Acad. Publishers).

Pasqua et al – Biologia Cellulare e Biotecnologie Vegetali (Piccin)

Smith et al – Biologia delle Piante: Evoluzione, Sviluppo, Metabolismo (Zanichelli)

Teaching methods

Lectures with PowerPoint presentations.

Assessment methods

A written report summarizing and interpreting a scientific article on a topic inherent to the course contents; oral exam.

Teaching tools

PowerPoint presentations; teaching material available on the on-line system IOL.

Office hours

See the website of Stefania Biondi