85861 - Chemistry And Biochemistry Of Plant Nutrition

Learning outcomes

By the end of the course, students will be familiar with the main chemical and biochemical processes governing the uptake of soil nutrients, which naturally take place at the soil-root interface. They will be able to interpret the connections between root activity, nutrient mobilization, and nutrient uptake. They will also be knowledgeable about the metabolic aspects of the main nutrients at the cellular level. A profound understanding of these processes provides an essential scientific basis for the efficient management of plant nutrition in agriculture.

Course contents

A) Prerequisites

This course represents the continuation of a study program that began in the Bachelor's degree programs, at the end of which students must have acquired knowledge regarding (i) the chemical, physical, and biological properties of the soil; (ii) the main transformations that nutrients undergo in the soil; (iii) knowledge of plant biology and biochemistry.

The relevant foundational courses are soil chemistry, agricultural biochemistry, soil fertility, agricultural microbiology, and plant biology. Students can deepen their prerequisite knowledge for this course by consulting the textbook FONDAMENTI DI CHIMICA DEL SUOLO Pàtron Ed. 2006, chapters 1, 3-10.

B) Didactic units

The course is divided into different didactic units (classroom lectures - 36 hours - and supporting learning activities - 24 hours)

Classroom lectures (36 hours)

1. Nutrients in soil and their availability (7 hours)

1.1 Plant Nutrients and Short-Distance Transport

Classification of plant nutrients and the criteria establishing their essentiality. Nutrient Use Efficiency (NUE), properties of root ionic absorption, short-distance transport of nutrients, apoplast, symplast, and transport mechanisms across biological membranes.

1.2 Nutrient Availability in Soil

Nutrient mobility in soil, factors determining their mobility, root development and nutrient localization, processes of rhizosphere formation.

Learning Outcomes for Unit 1:

Knowledge of the main processes underlying the absorption and transport of nutrients from soil to roots.

Knowledge of the key factors influencing nutrient availability and mobility in soil.

2. Chemical and Biological Properties of the Rhizosphere (7 hours)

 2.1 The Rhizosphere

 Processes of rhizosphere formation, root exudates, rhizospheric gradients, chemical properties of the rhizosphere, nitrogen forms and rhizospheric pH, redox potential in the rhizosphere.

Learning Outcomes for Unit 2:

Knowledge of the chemical, physical, and biological characteristics of the rhizosphere.

Knowledge of the main factors influencing the formation and properties of rhizospheric soil.

3. Nitrogen Nutrition (8 hours)

3.1 Nitrate Uptake

 Nitrogen in the soil-plant system, root uptake of nitrate, high- and low-affinity systems.

3.2 Ammonium Uptake

Cellular uptake of ammonium, low- and high-affinity systems.

3.3 Nitrate and Ammonium Assimilation

 Cellular mechanisms of nitrate and ammonium assimilation, nitrogen assimilation, and carbon metabolism.

Learning Outcomes for Unit 3:

Knowledge of the main root-level uptake mechanisms for nitrate and ammonium.

Knowledge of the main cellular-level mechanisms of nitrogen assimilation.

4. Phosphorus Nutrition (6 hours)

 4.1 Phosphate UptakePhosphorus in the soil-plant system, root uptake of phosphate, characteristics of membrane transporters.

4.2 Adaptation Mechanisms to Phosphate DeficiencyPhosphate mobilization strategies in the rhizosphere, cluster root formation, root exudates and phosphate deficiency, adaptation of cellular metabolism to phosphate deficiency.

Learning Outcomes for Unit 4:

Knowledge of the main root uptake mechanisms for phosphate.

Knowledge of the main mechanisms for adapting to phosphate deficiency in the soil.

5. Iron Nutrition (8 hours)

 Iron in the soil-plant system.

5.1 Strategy 1 for Iron Uptake

 Rhizosphere acidification, iron-reductase, cellular metabolic adaptations to iron deficiency, expression of membrane transporters, root exudation of carboxylates and organic acids.

5.2 Strategy 2 for Iron Uptake

 Cellular metabolism in graminaceous plants and phytosiderophore production, structure and chemical properties of phytosiderophores, expression of membrane transporters.

Learning Outcomes for Unit 5:

Knowledge of the main root uptake mechanisms for iron.

Knowledge of the main mechanisms for adapting to iron deficiency in the soil.

Didactic support activities (24 hours)

This part of the course will be dedicated to consolidating the knowledge provided, paying particular attention to the needs expressed by students over time, and through the organization of seminars on specific topics regarding: (1) the potential of stable isotopes for understanding the uptake of elements such as carbon, nitrogen, phosphorus, and sulfur by the plant; (2) advantages, disadvantages, and enhancement of the NUE of animal-based fertilizers; (3) applications for fertilization plans.

Readings/Bibliography

Slides presented during lectures. Lecture notes.Sections of textbooks provided by the lecturer.
Mineral Nutrition of Higher Plants – textbook available for consultation at the library (Marschner's – Edited by Petra Marschner - Academic Press).

Teaching methods

The course is divided into two parts:

1) Lectures: through the delivery of the teaching units in the classroom, students acquire the knowledge necessary to understand the chemical and biochemical processes underlying the mobilization and root uptake of nutrients from the soil. The acquisition of knowledge and understanding will be constantly monitored during lectures through continuous interaction between the lecturer and students. This lecturer-student interaction—which will take the form of discussing topics covered in the course, also in relation to their impact on highly topical issues inherent to the discipline—aims to promote the development of independent judgment and improve communication skills.

2) Supporting Educational Activity: students participate in seminars aimed at providing analytical parameters useful for predicting the chemical and biological processes that characterize nutrient availability in the soil. This part of the course will also aim to consolidate the knowledge acquired in the first part of the course.

"In consideration of the types of activities and teaching methods adopted, attendance at this training activity requires all students to complete Modules 1 and 2 in e-learning mode [https://www.unibo.it/it/servizi-e-opportunita/salute-e-assistenza/salute-e-sicurezza/sicurezza-e-salute-nei-luoghi-di-studio-e-tirocinio] and to participate in Module 3 of specific training on health and safety in places of study. Information on dates and attendance methods for Module 3 can be found in the specific section of the degree programme website."

Assessment methods

Learning assessment will take place through a written test held jointly with the other component of the integrated course of PLANT NUTRITION, which is Nutrition Microbiology.

The written exam consists of:

• 24 multiple-choice questions, divided as follows:
  • 12 in Chemistry and Biochemistry
  • 12 in Microbiology
• 2 open-ended questions, divided as follows:
  • 1 in Chemistry and Biochemistry
  • 1 in Microbiology

Each correct answer to the multiple-choice questions is worth 1 point. Each open-ended question is awarded from 0 to 3 points.

"Cum laude" (honors) is awarded upon achieving the maximum score of 24 in the multiple-choice questions and 6 in the open-ended questions for Nutrition Chemistry and Biochemistry and Nutrition Microbiology.

The maximum achievable score is 15 points for each discipline (Nutrition Chemistry and Biochemistry and Nutrition Microbiology), for a total of 30 points.

The exam takes place in person.

Registration for the exam must be done via AlmaEsami.

Within the 15 points of Microbiology, it is possible to obtain 4 addtional bonus points through:

• Participation in laboratory activities, with the production of a report;
• Participation in group activities, with the creation of a PowerPoint presentation.
• Non-attending students can produce a short report and a presentation on the teaching material made available on the Virtuale platform by the microbiology professors.

Students with SLD (Specific Learning Disorders) or temporary or permanent disabilities: It is recommended to contact the responsible University office in a timely manner (visit the Students with Disabilities and SLD office [https://site.unibo.it/studenti-con-disabilita-e-dsa/en] ); they will propose any necessary accommodations, which must in any case be submitted for the professor's approval at least 15 days in advance, who will evaluate their appropriateness in relation to the course's educational objectives.

Regarding learning assessment, the use of AI is prohibited. Any use constitutes a violation of academic integrity.

Teaching tools

For lectures and supporting activities, the following tools will be used: overhead projector, PC, video projector, and Microsoft Teams calls with laboratory technicians.

Office hours

See the website of Ilaria Braschi