Bennedsenfranck2528

Basic mechanisms are known to promote salt tolerance in plants a delay in Na+ uptake or rapid Na+ remobilization from leaf tissue. We measured dynamics of the Na+/K+ ratio and components of carbon metabolism during the first 72 h after saline stress (200 mM NaCl) began in Cenostigma pyramidale, a woody species, under controlled conditions. Saline stress at two times one plant group at the beginning of the morning and the other in the evening. Stressed plants had three times more Na+ in leaves than did control plants in the first 24 h. However, in the next few hours, despite new applications of saline solution, the Na+/K+ ratio continued to decline. Several samples, including night treatments, provided evidence that this species uses Na+ recirculation mechanisms to endure salt stress. Effects of salt on the traits evaluated differed depending on the time when stress began. Between the two saline treatments, in the first 24 h after saline stress, gas exchange decreased more strongly in morning-stressed plants, when large amounts of Na+ reached the leaf and K+ left this organ. Nevertheless, when stress was applied in the evening, leaf Na+ remobilization was faster, and the soluble sugar/starch ratio remained greater than did the control. Our data suggested that time of the beginning of salt stress could change the level of damage. Morning-stressed plants synthesized greater amounts of proline, H2O2, and malondialdehyde than did night-stressed plants. We recommend that details regarding the time of stress be taken into consideration in physiological studies.Seed viability is an important trait in agriculture which directly influences seedling emergence and crop yield. However, even when stored under optimal conditions, all seeds will eventually lose their viability. Our primary aims were to describe factors influencing seed deterioration, determine the morphological, physiological, and biochemical changes that occur during the process of seed ageing, and explore the mechanisms involved in seed deterioration. High relative humidity and high temperature are two factors that accelerate seed deterioration. As seeds age, frequently observed changes include membrane damage and the destruction of organelle structure, an increase in the loss of seed leachate, decreases of respiratory rates and ATP production, and a loss of enzymatic activity. These phenomena could be inter-related and reflect the general breakdown in cellular organization. Many processes can result in seed ageing; it is likely that oxidative damage caused by free radicals and reactive oxygen species (ROS) is primarily responsible. ROS can have vital interactions with any macromolecule of biological interest that result in damage to various cellular components caused by protein damage, lipid peroxidation, chromosomal abnormalities, and DNA lesions. Further, ROS may also cause programmed cell death by inducing the opening of mitochondrial permeability transition pores and the release of cytochrome C. Some repairs can occur in the early stages of imbibition, but repair processes fail if sufficient damage has been caused to critical functional components. As a result, a given seed will lose its viability and eventually fail to germinate in a relatively short time period.Productivity of sugarcane (Saccharum spp.) relies upon sucrose production in leaves and movement to sinks. The feedback regulatory effect of sugar upon photosynthesis balances this process involving Phosphoenolpyruvate carboxylase (PEPCase) and Rubisco where greater understanding in this area may allow manipulation to achieve higher yields. Accumulation of sucrose in leaves and decreased photosynthesis are early symptoms of the condition called yellow canopy syndrome (YCS) in sugarcane, which presents as a system in which to study sucrose feedback regulation. This work investigates changes in gene expression and protein abundance which coincide with the sugar accumulation in the leaves of YCS symptomatic sugarcane. During the early-stage of sugar accumulation, the levels of the Photosystem II core protein D1, and PsbQ of the oxygen-evolving complex decreased significantly. Transcript levels of these proteins also decreased, suggesting both nuclear and chloroplast gene expression were affected early in sugar build-up of YCS development. DX600 concentration Transcript level of primary carbon fixation reactions enzyme NADP malate dehydrogenase was especially downregulated. However, PEPCase, decarboxylation and re-fixation (Rubisco) enzymes were not negatively regulated at the transcript or protein abundance level. Phosphoenolpyruvate carboxykinase was upregulated in both gene expression and protein abundance. The Calvin cycle in the bundle sheath was sensitive through the CP12 protein. Two isoforms of CP12 were found, one of which showed downregulation which coincided with a decrease in CP12 protein. This suggests transcript and protein decrease of PEPCase and Rubisco may be secondary regulation points of the sugar feedback regulation process upon photosynthesis in sugarcane leaves.There is an increasing need of alternative treatments to control fungal infection and consequent mycotoxin accumulation in harvested fruits and vegetables. Indeed, only few biological targets of antifungal agents have been characterized and can be used for limiting fungal spread from decayed fruits/vegetables to surrounding healthy ones during storage. On this concern, a promising target of new antifungal treatments may be represented by mitochondrial proteins due to some species-specific functions played by mitochondria in fungal morphogenesis, drug resistance and virulence. One of the most studied mycotoxins is patulin produced by several species of Penicillium and Aspergillus genera. Patulin is toxic to many biological systems including bacteria, higher plants and animalia. Although precise biochemical mechanisms of patulin toxicity in humans are not completely clarified, its high presence in fresh and processed apple fruits and other apple-based products makes necessary developing a strategy for limiting its presence/accumulation. Patulin biosynthetic pathway consists of an enzymatic cascade, whose first step is represented by the synthesis of 6-methylsalicylic acid, obtained from the condensation of one acetyl-CoA molecule with three malonyl-CoA molecules. The most abundant acetyl-CoA precursor is represented by citrate produced by mitochondria. In the present investigation we report about the possibility to control patulin production through the inhibition of mitochondrial/peroxisome transporters involved in the export of acetyl-CoA precursors from mitochondria and/or peroxisomes, with specific reference to the predicted P. expansum mitochondrial Ctp1p, DTC, Sfc1p, Oac1p and peroxisomal PXN carriers.