Pepper abiotic stress resistance screening Stress part of the project Faculty of food and science & IUS

Climate change Plants gives only between 20-50% yield of their genetic potential. More than 200 million estimated loss in crop yield in BiH due to the climate change. For Mediterranean countries - biggest impact of climate change. Crops shifting to the north. Unpredictable weather patterns.

Plant stress measurement -Chilling (3 C) -High temperature (45 C) -Water lodging -Drought -?

The damage caused by stress can be physical or physiological. Physiological are: Primary- usually occur as an immediate response to the stress factor and cause dysfunction of the plant that is often reversible (e.g. photosystem inhibition). Secondary- their causes are the primary damages and their effect is usually irreversible. The appearance of characteristic visual symptoms is secondary damage.

Tissue Visible signs of damage caused by the stress (like sub-optimal temperature) on herbaceous organs are: loss of turgor pressure, the appearance of surface holes, dents and lysis, the accumulation of free water in the plant organs, loss of pigment, tissue shrinkage, drying and necrosis of leaf edges, accelerated aging, deterioration and cracking of tissue, slow, irregular or incomplete ripening or complete absence of maturation followed by lack of the basic structure of the fruit and flavor, increased ethylene production, increased and accelerated the emergence of rotting which stimulates the development of microorganisms, reducing the period of shelflife, and during prolonged exposure to adverse temperature complete loss of leaf mass and plant death.

Cell Stress can cause multiple disruptions in cell ultra structure. Most usual symptoms are the destruction of the cell wall and the cytoplasm membrane organelles, plasmalemma swelling and cracking, destruction of the endoplasmic reticulum, and the change in Golgi apparatus. The most obvious changes are taking place in the structure of mitochondria in the form of swelling and degradation. Stress can result in a distortion of plasmids, and chloroplasts membranes, reduction in the number of ribosomes, lipid accumulation and the reduction of starch. Stress can reduce the mitotic index in the apical meristem and reduction in number of newly formed cells in the root.

Stress mehanisam

Experiment setup Autochthonous variety (Čapljinska paprika) vs hybrid (Istar F1). Climate room-ideal temperature 25 C (no stress effect). Climate stress room, depending of stress type. Sampling in liquid nitrogen and storage at -80 C.

Stress measurements more than 500 samples for each Proline Electron leakage Relative water content ROS accumulation Trypan blue Total carbohydrates Antioxidative enzymes (SOD, CAT, APX) Lipid peroxidation (MDA)

Protoplast

Protoplast at IUS