Response of Mediterranean Ornamental Plants to Drought Stress

Abstract

Ornamental plants use unique adaptive mechanisms to overcome the negative effects of drought stress. A large number of species grown in the Mediterranean area offer the opportunity to select some for ornamental purposes with the ability to adapt to drought conditions. The plants tolerant to drought stress show different adaptation mechanisms to overcome drought stress, including morphological, physiological, and biochemical modifications. These responses include increasing root/shoot ratio, growth reduction, leaf anatomy change, and reduction of leaf size and total leaf area to limit water loss and guarantee photosynthesis. In this review, the effect of drought stress on photosynthesis and chlorophyll a fluorescence is discussed. Recent information on the mechanisms of signal transduction and the development of drought tolerance in ornamental plants is provided. Finally, drought-induced oxidative stress is analyzed and discussed. The purpose of this review is to deepen our knowledge of how drought may modify the morphological and physiological characteristics of plants and reduce their aesthetic value-that is, the key parameter of assessment of ornamental plants.

Effects of Water Stress on Gas Exchange, Water Relations and Leaf Structure in Two Ornamental Shrubs in the Mediterranean Area

“…Drought stress can also dramatically reduce plant survival after transplantation with high economic losses and impacts on the aesthetic quality of green areas [8].The successful establishment of ornamental green areas in Mediterranean regions can be achieved through the adequate selection of plant species characterized by a high tolerance to water stress [9]. Tolerant plants are those plants that have the ability to modify their metabolism to guarantee vital and essential physiological processes with a limited amount of water [10]; most of them are Mediterranean-native species.Drought-tolerant plants are able to modify, during water stress conditions, their morphology and to activate physiological and biochemical processes able to cope with water deficit [11,12]. The morphological modifications linked to drought stress reduce shoot and leaf growth, although the modality and the intensity of these phenomena depend on the genotypes, even within the same species [12].…”

“…Drought-tolerant plants are able to modify, during water stress conditions, their morphology and to activate physiological and biochemical processes able to cope with water deficit [11,12]. The morphological modifications linked to drought stress reduce shoot and leaf growth, although the modality and the intensity of these phenomena depend on the genotypes, even within the same species [12].…”

An Evaluation of Different Parameters to Screen Ornamental Shrubs for Salt Spray Tolerance

“…Photosynthesis is the most important physiological process in plants, and it must remain active, even under stress conditions, to maintain the growth and survival of the species. Plants under suboptimal conditions induce several biochemical and physiological strategies to cope with the adverse environment [34]. Therefore, the decline in photosynthesis activity represents an extreme mechanism for plants to avoid cell damage.…”

Abiotic Stress Effects on Performance of Horticultural Crops

“…These responses can have a direct impact on ornamental quality and subsequently on the commercial value of the plants. A review included in this special issue describes the physiological, biochemical, and morphological changes that ornamental plants can undergo under drought stress, and how these influence quality [10]. The most common changes that can be observed on leaves are smaller size and their orientation on the branch.…”