85861 - Chemistry And Biochemistry Of Plant Nutrition

Learning outcomes

At the end of the course, students would obtain the basic knowledge of chemical and biochemical processes, located at soil/root interface and determining nutrient uptake from soil and soil solution. The course will focus its attention to the relationships between root activities and nutrient mobilization and uptake. Moreover basic knowledge on the metabolism of the main nutrients will be provided.

Course contents

A) Prerequisites

The present course represent the continuation of the educational path started in the other course of the First Cycle Degree, after which students should have a good knowledge of:

- Soil physical, chemical and biochemical properties

- Soil nutrient main transformations

- Plant biology and biochemistry

The related courses are soil chemistry, agricultural biochemistry, soil fertility, agricultural microbiology and plant biology.

B) Didactic units

The course is divided into different didactic units

1. Nutrient elements in soil and their availability (8 hours)

1.1 Nutrients and short distance transportation

Nutrient classification and criteria to define them as essential. Nutrient Use Efficiency (NUE), root ionic absorption properties, nutrient short distance transportation, apoplast, symplast, transportation across biological membranes

1.2 Nutrients and short distance transportation

Nutrient mobility in soil, factors determining nutrient mobility, root development and nutrient localization, rhyzosphere formation processes.

Knowledge gained in Didactic Unit 1

- Main processes linked to nutrient absorption and transportation from soil to roots

- Main factors influencing nutrient availability and mobility in soil

2. Rhizosphere chemical and biological properties (7 hours)

2.1 Rhizosphere

Rhizosphere formation processes, root secretions, rhizospheric gradients, rhizosphere chemical processes, nitrogen forms and rhizospheric pH, rhizosphere redox potential

Knowledge gained in Didactic Unit 2

- Rhizosphere physical, chemical and biological characteristics

- Main factors influencing rhizospheric soil formation and properties

3. Nitrogen nutrition (7 hours)

3.1 Nitrate absorption

Nitrogen in the soil/plant system, nitrate root absorption, low and high affinity systems.

3.2 Ammonium absorption

Ammonium cellular absorption, low and high affinity systems

3.3 Nitrate and ammonium assimilation

Nitrate and ammonium assimilation cellular mechanisms, nitrogen assimilation, carbon metabolism

Knowledge gained in Didactic Unit 3

- Main nitrate and ammonium absorption mechanisms at root level

- Main nitrate and ammonium assimilation mechanisms at cellular level

4. Phosphorous nutrition (7 hours)

4.1 Phosphate absorption

Phosphorous in soil/plant system, phosphate root absorption, membrane transporter characteristics

4.2 Mechanisms of adaptation to phosphate deficiency

Mechanisms of phosphate mobilization in rhizosphere, cluster root formation, root secretions and phosphate deficiency, cellular metabolism adaptation and phosphate deficiency

Knowledge gained in Didactic Unit 4

- Main mechanisms of root phosphate absorption

- Main mechanisms of adaptation to phosphate deficiency in soil

5. Iron nutrition (7 hours)

Iron in soil/plant system

5.1 Iron absorption strategy I

Rhizosphere acidification, iron reductase, metabolic cellular adaptation to iron deficiency, membrane transporter expression, root exudation of carboxylates and organic acids

5.1 Iron absorption strategy II

Graminaceous plant cellular metabolism and phyto-siderophores production, phyto-siderophores structure and chemical properties, membrane transporter expression

Knowledge gained in Didactic Unit 5

- Main mechanisms of root iron absorption

- Main mechanisms of adaptation to iron deficiency

6. Didactic support activities (24 hours)

Laboratory activities

Laboratory activities will be focused on the analysis of some of the main soil nutrients. At the end of each exercise, students should write a brief report.

Consolidation activities

This part of the course will be dedicated to the consolidation of the knowledge provided during the lessons, with particular attention to the needings raised by the students.

Readings/Bibliography

Slides presented during lessons. Lessons notes. Teacher didactic material.

Mineral Nutrition of Higher Plants (Marschner's- Edited by Petra Marschner- Academic Press), available from the teacher

Teaching methods

The course is subdivided into two parts:

1) Class lectures: Students should gain the knowledge on chemical and biochemical processes leading nutrient mobilization and root absorption in soil, through class lectures. Knowledge acquisition and comprehension skills will be constantly monitored, during class lectures, through a continue interaction between the students and the teacher. Such interaction consists in requests by the teacher of discussing some topics of the course, for their impact on current issues linked to the subject of the course, and will aim at developing judgement autonomy and improving communication skills

2) Didactic support activities: Students should attend laboratory exercises, aiming at providing analytical results for the evaluation of chemical and biological processes linked to nutrient availability in soil. Such part of the course will also aim at verifying the ability of applying the theoretical knowledge gained in the first part of the course.

Assessment methods

The learning test for this course is made through a final oral examination, carried out together with the exam of the second module (Nutrition Microbiology) of the integrated course. The oral exam deals with the topics developed in the lessons of the two courses. The academic board will evaluate the scores of each learning subject, making a weighed mean of them to express the final score. You can, on request, sustain the final exam in English.

Teaching tools

Overhead projector, personal computer and projector will be used for class lectures.

Laboratory exercises will take place in the didactic laboratories of Agricultural Chemistry and Biochemistry.

Office hours

See the website of Ilaria Braschi