The availability of inorganic phosphate (Pi) often limits plant growth and crop productivity. The signaling mechanisms governing Pi starvation responses in plants include responses to external Pi concentrations to modify the root system architecture and responses to internal Pi concentrations to maintain Pi homeostasis. How these signaling mechanisms are coordinated is unclear but Pi itself […]
The structure and biogenesis of the eukaryotic 80S ribosome are similar in all eukaryotes, as are the ribosomal RNAs (rRNAs) and ribosomal proteins involved in these processes. The biogenesis of the 80S ribosome in eukaryotes is best characterized in the yeast Saccharomyces cerevisiae. Indeed, the individual functions of many plant and animal ribosome biogenesis factors […]
The plastids of Euglena gracilis, a freshwater photosynthetic flagellate, are embedded by three membranes. These membranes are an evolutionary vestige of the secondary endosymbiotic event that occurred between a phagotrophic eukaryovorous euglenid and a Pyramimonas-related green alga. The plastids of Euglena are unusual in being surrounded by only three membranes: most secondary plastids are surrounded […]
Melatonin has diverse effects on plant growth and development and has been implicated in tolerance to abiotic stresses such as drought, salinity, freezing, and high temperature. The protective role of melatonin against biotic stresses in plants, however, remains unclear. Huanglongbing (HLB), popularly known as citrus greening disease, was first noted in China in the early […]
About 20% of irrigated land is considered saline, with the amount of saline soils increasing worldwide. This trend is alarming due to the high salt sensitivity of most crop species. Yield reduction in crops in saline soils amounts to losses in the order of 12 to 27.3 billion US dollars annually. Thus, the improvement of […]
In land plants, water is lost primarily by transpiration through stomata. However, when the aerial tissues begin to dry, the stomata close, and transpiration, much reduced, occurs mostly from the apoplast of epidermal cells. The hydrophobic cuticle that coats the epidermis of aerial organs provides the key barrier against this flux. Despite extensive research, however, […]
The reproductive structures of the Asteraceae (the sunflower family), the largest family of flowering plants, are among the most complex within the flowering plants. The species in this family develop head-like inflorescences that resemble flowers. In many Asteraceae flowers, the hermaphroditic disc flowers are less conspicuous and radially symmetrical and are located in the center […]
Wood formation is controlled by a number of MYB family transcription factors, which may act as transcriptional activators or repressors. Secondary wall associated NAC domains (SNDs) and vascular-related NAC domains are master regulators controlling the expression of downstream transcription factors, including MYB proteins. There appears, therefore, to be a transcriptional regulatory network (TRN) where activators […]
Several recent studies have revealed that reactive oxygen species (ROS)waves propagate through plants, originating at the treated, stimulated, or stressed local tissue and spreading within minutes to the entire plant. ROS waves regulate and coordinate systemic metabolic, molecular, and physiological responses among the different parts of the plant. Interestingly, in Arabidopsis (Arabidopsis thaliana), an excess […]