Chronic neuroprotective effects of low concentration lithium on SH-SY5Y cells:possible involvement of stress proteins and gene expression

To investigate the molecular mechanism underlying the neuroprotective effect of lithium on cells, in this study, we exposed SH-SY5Y cells to 0.5 mmol/L lithium carbonate （Li2CO2） for 25-50 weeks and then detected the expression levels of some neurobiology related genes and post-translational modifications of stress proteins in SH-SYSY cells, cDNA arrays showed that pyruvate kinase 2 （PKM2） and calmodulin 3 （CaM 3） expression levels were significantly down-regulated, phosphatase protein PP2A expression was lightly down-regulated, and casein kinase II （CK2）, threonine/tyrosine phosphatase 7 （PYST2）, and dopamine beta-hydroxylase （DBH） expression levels were significantly up-regulated. Besides, western blot analysis of stress proteins （HSP27, HSP70, GRP78 and GRP94） showed an over-expression of two proteins： a 105 kDa protein which is a hyper-phosphorylated isoform of GRP94, and a 108 kDa protein which is a phosphorylated tetramer of HSP27. These results suggest that the neuroprotective effects of lithium are likely related to gene expressions and post-translational modifications of proteins cited above.

Sap flow rates of Minquartia guianensis in central Amazonia during the prolonged dry season of 2015–2016

Minquartia guianensis Aubl.is a slow-growing species with several uses.In the juvenile state,it is well-adapted to low light conditions of the forest understory.However,it is still unknown how climate variability affects transpiration of this species,particularly under drought stress.In this study,we aimed to assess the effect of climatic variability on sap flow rates(SFR).SFR and radial growth were measured in six trees(14-50 cm diameter)in 2015 and 2016.Climate(precipitation,irradiance,relative humidity and temperature)and soil water content(SWC)data were also collected.SFR tended to increase in the dry season,with a negative relationship between SFR and SWC and precipitation(p<0.001),while there was a positive association between radial growth and monthly precipitation(p=0.004).Irradiance and temperature were the environmental factors more closely correlated with SFR during daytime(p<0.001),whereas relative humidity and vapor pressure deficit were the most important factors at night(p<0.001).Although negative SFR were sometimes recorded at night,the mean nocturnal sap flow was positive and across trees the nighttime sap flow accounted for 12.5%of the total daily sap flow.Increased transpiration during the dry season suggests that the root system of Minquartia was able to extract water from deep soil layers.These results widen our understanding of the ecophysiology of Amazonian trees under drought and provide further insight into the potential effect of the forecasted decline in precipitation in the Amazon region.

Chemical Screening of <i>Urochloa humidicola</i>: Methods for Characterizing Secondary Metabolites and Allelopathic Activity on Forage Legumes

The aim of this study was to identify the main classes of secondary metabolites present in the root and shoot crude extracts and fractions from the forage grass Urochloa humidicola (Rendle) Morrone & Zuloaga and to evaluate the allelopathic effect of these metabolites on forage legumes for intercropping. Phytochemical prospecting analyses, 1H NMR and capillary electrophoresis were performed on extracts of U. humidicola. Allelopathic activity was evaluated in germination of Stylosanthes, Macrotyloma axillare and Lactuca sativa L. (standard) in the presence of crude extracts, isolated saponins, flavonoids and trans-cinnamic acid. The metabolite classes present in the extracts could be determined by the combined use of the tested analytical techniques, but their use alone was usually not sufficient to chemically characterize the species. Capillary electrophoresis was effective in detecting phenolic compounds. Macrotyloma axillare was tolerant to crude extracts of U. humidicola. Saponins and trans-cinnamic acid, but not the flavonoids, reduced germination of the target plants.

Mesophyll thickness and sclerophylly among Calotropis procera morphotypes reveal water-saved adaptation to environments

Calotropis procera(Aiton)Dryand(Apocynaceae)is a native species in tropical and subtropical Africa and Asia.However,due to its fast growing and drought-tolerant,it has become an invasive species when it was introduced into Central and South America,as well as the Caribbean Islands.Currently,C.procera displays a wide distribution in the world.Invasiveness is important,in particular,because many invasive species exert a high reproductive pressure on the invaded communities or are highly productive in their new distributed areas.It has been suggested that a very deep root system and a high capacity to reduce stomatal conductance during water shortage could allow this species to maintain the water status required for a normal function.However,the true mechanism behind the successful distribution of C.procera across wet and dry environments is still unknown.C.procera leaves were collected from 12 natural populations in Brazil,Colombia and Mexico,ranging from wet to dry environments during 2014–2015.Many traits of morphology and anatomy from these distinct morphotypes were evaluated.We found that C.procera leaves had a considerable capacity to adjust their morphological,anatomical and physiological traits to different environments.The magnitude of acclimation responses,i.e.,plasticity,had been hypothesized to reflect the specialized adaptation of plant species to a particular environment.However,allometric models for leaf area(LA)estimation cannot be grouped as a single model.Leaves are narrower and thicker with low amounts of air spaces inside the leaf parenchyma in wet environments,while they are broader and thinner with a small number of palisade cell layers in dry environments.Based on these,we argue that broader and thinner leaves of C.procera dissipate incident energy at the expense of a higher rate of transpiration to survive in environments in which water is the most limiting factor and to compete in favorable wet environments.

thylenediurea(EDU)effects on Japanese larch:an one growing season experiment with simulated regenerating communities and a four growing season application to individual saplings

Japanese larch(Larix kaempferi(Lamb.)Carr.)and its hybrid are economically important coniferous trees widely grown in the Northern Hemisphere.Ground-level ozone(O_(3))concentrations have increased since the preindustrial era,and research projects showed that Japanese larch is susceptible to elevated O_(3)exposures.Therefore,methodologies are needed to(1)protect Japanese larch against O_(3)damage and(2)conduct biomonitoring of O_(3)in Japanese larch forests and,thus,monitor O_(3)risks to Japanese larch.For the first time,this study evaluates whether the synthetic chemical ethylenediurea(EDU)can protect Japanese larch against O_(3)damage,in two independent experiments.In the first experiment,seedling communities,simulating natural regeneration,were treated with EDU(0,100,200,and 400 mg L^(-1))and exposed to either ambient or elevated O_(3)in a growing season.In the second experiment,individually-grown saplings were treated with EDU(0,200 and 400 mg L-1)and exposed to ambient O_(3)in two growing seasons and to elevated O_(3)in the succeeding two growing seasons.The two experiments revealed that EDU concentrations of 200-400 mg L^(-1)could protect Japanese larch seedling communities and individual saplings against O_(3)-induced inhibition of growth and productivity.However,EDU concentrations≤200 mg L^(-1)did offer only partial protection when seedling communities were coping with higher level of O_(3)-induced stress,and only 400 mg EDU L^(-1)fully protected communities under higher stress.Therefore,we conclude that among the concentrations tested the concentration offering maximum protection to Japanese larch plants under high competition and O_(3)-induced stress is that of 400 mg EDU L^(-1).The results of this study can provide a valuable resource of information for applied forestry in an O_(3)-polluted world.

High-throughput Phenotyping and Genomic Selection:The Frontiers of Crop Breeding Converge

Genomic selection （GS） and high-throughput phenotyping have recently been captivating the interest of the crop breeding com- munity from both the public and private sectors world-wide. Both approaches promise to revolutionize the prediction of complex traits, including growth, yield and adaptation to stress. Whereas high-throughput phenotyping may help to improve understanding of crop physiology, most powerful techniques for high-throughput field phenotyping are empirical rather than analytical and compa- rable to genomic selection. Despite the fact that the two method- ological approaches represent the extremes of what is understood as the breeding process （phenotype versus genome）, they both consider the targeted traits （e.g. grain yield, growth, phenology, plant adaptation to stress） as a black box instead of dissectingthem as a set of secondary traits （i.e. physiological） putatively related to the target trait. Both GS and high-throughput phenotyping have in common their empirical approach enabling breeders to use genome profile or phenotype without understanding the underlying biology. This short review discusses the main aspects of both approaches and focuses on the case of genomic selection of maize flowering traits and near-infrared spectroscopy （NIRS） and plant spectral reflectance as high-throughput field phenotyping methods for complex traits such as crop growth and yield.