STRESS PHYSIOLOGY AND BIOINDICATION

Degree course: 
Corso di Second cycle degree in Biology and Sustainability
Academic year when starting the degree: 
2023/2024
Year: 
1
Academic year in which the course will be held: 
2023/2024
Language: 
Italian
Credits: 
12
Period: 
First Semester
Standard lectures hours: 
100
Requirements: 

knowledge of plant biology

Final Examination: 
Orale

The final exam is oral: the student must show
1) the understanding of the covered topics;
2) the ability to interconnect the acquired knowledge;
3) the completeness of the acquired knowledge;
4) the use of a proper terminology;

Assessment: 
Voto Finale

The course contributes to achieving the educational objectives of the Biology and Sustainability degree course by providing in-depth knowledge in the field of interactions between plants and biotic and abiotic stresses, as well as adaptation strategies (avoidance, tolerance, resilience, resistance). At the end of the course, students will:
• Understand the physiological processes and molecular mechanisms that allow plants to successfully adapt to environmental stresses.
• Understand the mechanisms underlying plant physiological responses to pathogens.
• Understand the necessary tools to analyze plant responses to stresses and climate change.
• Be encouraged to develop autonomy in judgment and to communicate acquired concepts using the correct scientific language.
They will be able to use the acquired knowledge to:
• Identify biotic and abiotic stress situations.
• Develop strategies and research projects to improve or preserve green ecosystems in unfavorable environments, thereby contributing to the sustainable management of resources

General definition of stress and common strategies of avoidance, tolerance, resilience, and resistance.
Oxidative stress. Reactive oxygen species: chemistry, sources of ROS in plant cells, antioxidant systems.
Water and salt stress. Molecular, cellular, and organismic damage by water deficiency. Molecular, physiological, and anatomical mechanisms of resistance and adaptation to drought. Flooding and submersion: molecular, cellular, and organismic damage. Fermentations and cytoplasm acidification. Adaptive, avoidance, and tolerance responses to hypoxia and anoxia. Physiological strategies of salt resistance and tolerance. Osmoregulation. Regulation mechanisms of NaCl absorption and accumulation in plants.
Heat stress. Cold and freezing stress. Cellular damage and adaptive responses to cold. Osmoregulators and cryoprotectants. Protection mechanisms of the photosynthetic apparatus. Cellular damage and adaptive responses to high temperatures. Heat shock proteins and factors in stress. Secondary metabolites and their functions in thermoprotection.
Light stress. Shade plants: physiological adaptation mechanisms to low light. Adaptive responses of plants under vegetative cover. High light intensity stress. Sun plants: structural and functional characteristics underlying adaptation and tolerance. Photosynthetic ROS production and photoinhibition. Molecular mechanisms of photoprotection: excess energy dissipation. Violaxanthin cycle, state transition, cyclic electron transport, water-water cycle, chlororespiration. Damage to PSII and repair.
Anthropogenic pollution stress. Soil, water, and atmospheric pollutants. Characteristics, toxicity, and mechanisms of tolerance and resistance. Use of bioindicators for environmental quality. Detoxification systems and phytoremediation.
Biotic stress: plant-pathogen interaction. Constitutive defense. Innate immunity in plants: PAMP, DAMP, and basal immunity. Secondary metabolites in defense mechanisms. Effectors and R genes. Oxidative burst. Hypersensitive response. Systemic acquired resistance (SAR). Salicylic acid and jasmonic acid. Intracellular and long-distance signaling.
Laboratory exercises will allow learning of some techniques to evaluate the effects of stress on plants.

Convenzionale

The course is organized in lectures (40h) and laboratory activities (12 h).

Recommended textbooks:
Slides of lessons and scientific papers on the topics presented during lessons.