DESERT PLANTS SEEDS MORPHOLOGY AND GERMINATION STRATEGY International Journal of Conservation Science, 2022
Floristic diversity in hydro-closed ecosystem: Lake between the two dams, aswan, egypt Ecology Environment and Conservation, 2020
Alkaloid role in plant defense response to growth and stress Abeer H. Ali, Mostafa Abdelrahman, Magdi A. El-Sayed Bioactive Molecules in Plant Defense Signaling in Growth and Stress, 2019 In the natural habitats, plants are surrounded by a different number of enemies, including a wide variety of viruses, bacteria, fungi, nematodes, insects, and other herbivorous, which are responsible for the deleterious reduction in plant growth and production. Plants protect themselves by producing a diverse array of compounds called secondary metabolites, including terpenes, phenolics, sulfur-containing compounds, saponins, and alkaloids. Alkaloids are a diverse group of nitrogen-containing basic natural products consisting of more than 20 different classes including pyrrolidines, pyrrolizidine, quinolizidine, tropanes, piperidines, pyridines, and others. Most alkaloids are believed to function as (1) storage reservoirs of nitrogen, (2) defensive elements against predators, especially animals, vertebrates, insects as well as arthropods due to their general toxicity and deterrence capability, and (3) growth regulators, since the structures of some alkaloids are similar to known plant growth regulators. In addition, a number of alkaloids are being used as a source of medicinal drugs for thousands of years due to their structure–activity relationship, and this line of interest is still a major one for organic chemistry and pharmaceutical industries. For example, quinine, which is derived from the bark of tropical cinchona tree, has been used by Indians of South America for fever treatment and later proved to be an essential remedy needed for malaria disease. Considerable efforts have been carried out in the biosynthesis pathways of alkaloids and their intermediate compounds. This chapter presents an overview of the recent studies on the role of alkaloids as specific plant protectants to pathogen attack and other damaging creatures. In addition, we critically evaluate the availability and significant of alkaloid’s genetic resources with desirable biotic stress resistance traits.
The role of the endophytic fungus, Thermomyces lanuginosus, on mitigation of heat stress to its host desert plant Cullen plicata Abeer H. Ali, Usama Radwan, Soad El-Zayat, Magdi A. El-Sayed Biologia Futura, 2019 Endophytic fungi associated with desert plants have a crucial role to enable these plants to tolerate abiotic stress, such as heat and drought. In this study, a thermophilic fungal endophyte was isolated from a hot desert-adapted plant, Cullen plicata Delile. The endophytic fungus was (molecularly) identified as Thermomyces lanuginosus, and inoculated plants were coded as E+ and the control as E-. This fungus had an effective growth-promoting activity on its host plant and increased the plant resistance to heat stress as well. Our findings demonstrate that thermophilic fungal endophytes can enhance drought and heat stress tolerance in desert plants by ecophysiological mechanisms and improve growth of its host plants.
Effect of Thermomyces fungal endophyte isolated from extreme hot desert-adapted plant on heat stress tolerance of cucumber Abeer H. Ali, Mostafa Abdelrahman, Usama Radwan, Soad El-Zayat, Magdi A. El-Sayed Applied Soil Ecology, 2018 With the increasing effects of global climate change and population growth, there is a high need for new agricultural practices to maximize efficiencies and reduce the efforts needed for developing new crop varieties that can withstand various abiotic stress. Plant-microbe association to optimize plant growth and increase plant host stress tolerance may play an essential role in improving environmental sustainability and economic viability, especially in the arid land habitats. In the present study, photosynthetic responsiveness was selected to demonstrate that a theromophilic endophytic (CpE) fungus isolated from the hot desert-adapted delile (Cullen plicata) roots can mediate heat stress tolerance in cucumber plants grown in the field during the summer season in Egypt. Initially, the CpE isolate was identified using an internal transcribed spacer, revealing 92% sequence homology with Thermomyces sp. Then the cucumber seeds were treated with CpE endophyte spore and allowed to grow in a growth chamber for three weeks before transplanting into the field station from May to July. The CpE treatment eliminates the adverse effects of heat stress on cucumber plants by maintaining the maximum quantum efficiency of photosystem II, photosynthesis rate, water use efficiency and increase root length relative to untreated plants. In addition, CpE treatments induced the significant accumulation of total sugars, flavonoids, saponins, soluble proteins and antioxidant enzyme activities in comparison with untreated cucumber plants. Our finding provides novel insights into the eco-physiological mechanisms of thermophilic CpE-mediated heat stress tolerance in cucumber, which signify the prospective applications of arid land-adapted endophytes in agricultural systems.
