Kuivusstressi

Kuivusstressi refers to the physiological and biochemical responses of plants to water deficit. This condition arises when the rate of water loss from the plant, primarily through transpiration, exceeds the rate of water uptake from the soil. It is a significant abiotic stress that can limit plant growth, development, and yield across various agricultural and natural ecosystems.

The initial response of a plant to water shortage is often a reduction in leaf turgor pressure, leading to wilting. This wilting can be observed as a visible drooping of leaves. Beyond wilting, plants initiate a cascade of internal adjustments. Stomatal closure is a key early mechanism, reducing water loss through transpiration but also limiting carbon dioxide uptake, thereby impacting photosynthesis. Hormonal changes, particularly an increase in abscisic acid (ABA), play a crucial role in signaling and regulating these responses.

Prolonged or severe kuivusstress can lead to more detrimental effects. Photosynthetic efficiency declines significantly, and plants may experience oxidative stress due to the overproduction of reactive oxygen species. Cellular damage can occur, affecting enzymes and other vital biomolecules. Ultimately, if water deficit is severe and sustained, it can result in reduced biomass accumulation, impaired reproduction, and even plant death. Understanding and managing kuivusstress is vital for agricultural productivity and ecological resilience.