18756 - Biology of Plant Development

Course Unit Page

Academic Year 2018/2019

Learning outcomes

At the end of the course, the student will have acquired a deeper knowledge, in particular at the molecular level, of main aspects of the plant cell (cell cycle, cytoskeleton, cell wall) and of the regulation of plant development (embryo, shoot apex, root, flower) in Angiosperms. The student will have learned the principal methodologies currently used to study these aspects of plant biology and will be able to critically read and interpret recent scientific publications on these topics.

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.

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.

Plant cell wall: chemical composition and main functions of primary and secondary cell walls; cell wall proteins;

Cytoskeleton : structure and functions. Methods for measuring changes in cellular calcium levels (imaging, cells transformed with aequorin).

Programmed Cell Death: mechanisms and functions in development and pathogenesis.

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 and trichomes.

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). Cytokinins and cell cycle control; brassinosteroids; strigolactones.

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

Assessment methods

A written report based on a scientific article and an oral examination

Teaching tools

Power Point presentations

Office hours

See the website of Stefania Biondi