Drought is a natural phenomenon that has been affecting civilizations throughout history. It is estimated that more than 60% of the world’s population live in areas with potential risk of severe water scarcity in the next 30 years.

By Muhammad Muzamil Ijaz, Dr. Adnan Younis, Dr. Madiha Butt, Dr. Nasir Ahmad Khan and Dr. Ahsan Akram

Drought Stress:

The search for plants tolerant to drought conditions is an important task that should be undertaken to secure food supplies for these populations. A drought occurs when there is a lack of water for an extended period of time. It can cause the leaves of plants to turn yellow, and the plants may not produce flowers and fruit. The roots of plants may also dry out, which can stunt the plant’s growth. Several ways to help protect plants from drought stress include watering them regularly, using inorganic fertilizer and adding mulch to keep the soil moist and choosing drought-tolerant plants.

Drought stress is a major factor in climate change and crop production. In fact, it is estimated that up to 30% of global crop production is lost each year due to drought stress. It is important to understand how drought stress affects plants so that we can better manage these stresses and improve crop yields.

Causes of Drought Stress:

Drought stress is a major problem for plants all over the world. There are several causes of drought stress, including lack of water, nutrients, and high temperatures. These factors can severely damage plants and reduce their ability to produce food or flowers.

Symptoms of Drought Stress: 

Symptoms of drought stress can include ROS production, wilting, poor growth, and browning. The most common sign of drought is wilting. If the soil is too dry, the plant can’t take up water through its roots, so the leaves will drop. Poor growth can also be a sign of drought stress. The plant may not grow as tall or wide as it should, and the leaves may be smaller than normal. Browning is another sign of drought stress. The leaves may turn brown and crispy, and the plant may die if it doesn’t get enough water.

Effects of ROS on Plant Physiology;

One of the mechanisms by which plants respond to drought stress is the production of reactive oxygen species (ROS). ROS can damage cellular components, leading to reduced plant growth and productivity. The metabolism of ROS is also affected by drought stress, resulting in changes in the levels of different ROS species. Understanding the effects of drought stress on ROS metabolism can help us develop strategies to improve plant tolerance to drought. There is a high correlation between ROS levels and the extent of dehydration in plants. This suggests that ROS levels can be used as an indicator of plant stress and that the accumulation of ROS may provide a useful tool for studying drought tolerance.

Reactive oxygen species (ROS) are generated as byproducts of normal metabolic processes in plants and can also be induced by environmental stresses such as drought. Studies have shown that mitigation of ROS levels through the use of antioxidants can help improve plant tolerance to drought stress. A recent study on the effects of plant antioxidative defense in plants revealed that an increase in oxidative stress due to drought resulted in a decrease in antioxidant capacity and increased damage to cell membranes, which was associated with decreased photosynthetic capacity. 

Management of Drought Stress: 

When a plant is drought-stressed, its ability to take up water from the soil is reduced. This can lead to wilting, yellowing, and even the death of the plant. In order to better manage drought stress, it is important to understand how plants uptake water and what methods can be used to improve water availability. Silicon is a beneficial element that can help plants cope with drought stress. Silicon uptake reduces water loss from the leaves and helps the plant retain more water in the soil. Mulching also helps improve water availability by reducing evaporation from the soil surface. It is important to choose the right planting location based on the amount of rainfall available in order to reduce drought stress. 

Mechanism of Silicon Action: 

The uptake of Silicon by plants is an important process in plant drought tolerance. Silicon (Si) uptake and translocation to leaves are enhanced when plants are exposed to drought stress. The molecular mechanism of Si uptake occurs through the root hair cells and involves several membrane proteins. Once inside the cells, Si is transported to the leaf chloroplasts, where it is incorporated into the cell walls. This increases the cell’s resistance to dehydration and improves water use efficiency. 

Silicon and Plant Growth: 

Scientists from the University of California, Riverside published a study that showed a link between plant growth and silicon uptake. The study found that when plants are given silicon supplements, they can better tolerate drought conditions. Silicon is not a nutrient that is typically found in soil, but it is known to be important for plant growth. The study showed that when plants were given silicon supplements, they could take up more water and survive in drier conditions. 

When plants are subjected to drought stress, they undergo a number of molecular and physiological changes in order to conserve water. One of these changes is an increased uptake of Silicon. It is a beneficial element for plants and can help them cope with drought stress. Silicon is a mineral found in high concentrations in the Earth’s crust, but it is not essential for plant growth. It helps to protect plants from drought stress, increases the water-holding capacity of the soil and better uses available water. Additionally, Si increased photosynthesis and chlorophyll a/b ratios and help to protect plants from damage caused by drought-related stresses such as oxidative stress and cell membrane leakage.