Effects of elevated pO_3 on carbon cycle between above andbelowground organs of trees

Translocation of carbohydrate from leaves to roots via phloem and reallocation from roots to leaves via xylem regulate the allocation of carbon （C） between above and belowground organs of trees. To quantitatively analyze effects of elevated ozone concentrations pO3 on the internal cycle of C, juvenile beech and spruce were grown in phytotrons and exposed to ambient and elevated pO3 （i.e. twice-ambient O3 levels, restricted to 〈 150 ppb） for two growing seasons. The translocation of C in the phloem and xylem was quantitatively studied by investigating the phloem/xylem-loading of sugars, the differentiation of stem conductive tissue and the hourly water flow through the stem. Results in the present study shown, elevated pO3 significantly decreased C translocation from shoot to roots in beech by reducing both sugar concentration in the phloem and conductive phloem area. Elevated pO3 also significantly decreased C reallocation from the roots to the shoot in beech by reducing both of sugar concentration in the xylem and transpiration rate. The adverse effects of elevated pO3 on C translocation in the phloem and xylem, however, were small in spruce. Contrasting to beech, spruce is less sensitive to elevated pO3, regarding to phloem differentiation and sugar concentrations in the phloem and xylem.

Latest Achievements on Climate Change and Forest Interactions in a Polluted Environment

The COST Action FP0903 “Climate Change and Forest Mitigation and Adaptation in a Polluted Environment (MAFor)” involved 29 countries and created a platform for information exchange with experts from different fields, with the following main objectives: 1) to increase understanding of the state and potential of forest mitigation and adaptation to climate change in a polluted environment and 2) to reconcile process-oriented research, long-term monitoring and applied modelling at comprehensive forest research sites. In particular, MAFor translated the existing European knowledge on climate and air pollution dynamics into prospects for forest research and monitoring, with focus on the carbon, ozone, nitrogen and water budgets. The aim of this paper is to summarize scientific activities and achievements of MAFor: the creation of a meta-database for highlighting the available data and integrating the information from European forest research/monitoring networks;the development of a new concept of forest sites for research and monitoring (Supersites);the identification of the main knowledge gaps;and the definition of priorities for forest adaptation to climate change in a polluted environment. The action also increased European capacity building in this sector by organizing five conferences, granting 64 short-term scientific missions, organizing four training schools and publishing more than 100 papers.

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.

Molluscicidal activity of chlorophyll extraction against the freshwater snails

Objective:To evaluate the molluscicidal activity of chlorophyll extract as a photodynamic substance against the snails Lymnaea stagnalis,Biomphalaria spp.and Physa marmorata.Methods:Chlorophyllin was extracted from deep-frozen spinach.Snails were incubated in chlorophyllin containing water with 2.5,5.0,10.0 and 15.0μg/mL.All samples were kept in darkness overnight for incubation.After incubation,three samples were irradiated with simulated solar radiation for 3 h.After irradiation,the vitality of the organisms was determined.Results:The photodynamically active chlorophyllin,at low concentrations,was able to kill snails within a few hours under exposure of solar radiation.Besides,it had a killing effect by about 70%and 100%on the snails’eggs and the newly hatched snails,respectively,after 3 h exposure to solar radiation.Conclusion:The derivates of chlorophyll was a very interesting substance for photodynamic freshwater snail control.Hence,it might be a promising and cheap new strategy which probably had the potential to replace the synthetic molluscicides for snail control.

Spatial H202 Signaling Specificity： H202 from Chloroplasts and Peroxisomes Modulates the Plant Transcriptome Differentially

Hydrogen peroxide （H2O2） operates as a signaling molecule in eukaryotes, but the specificity of its signal- ing capacities remains largely unrevealed. Here, we analyzed whether a moderate production of H2O2 from two different plant cellular compartments has divergent effects on the plant transcriptome. Arabidopsis thaliana overexpressing glycolate oxidase in the chloroplast （Fahnenstich et al., 2008; Balazadeh et al., 2012） and plants deficient in peroxisomal catalase （Queval et al., 2007; Inze et al., 2012） were grown under non-photorespiratory conditions and then transferred to photorespiratory conditions to foster the production of H202 in both organelles. We show that H202 originating in a specific organelle induces two types of responses： one that integrates signals independently from the subcellular site of H202 production and another that is dependent on the H2O2 production site. H2O2 produced in peroxisomes induces transcripts involved in protein repair responses, while H2O2 produced in chloroplasts induces early signaling responses, including transcription factors and biosynthetic genes involved in production of secondary signaling messengers. There is a significant bias towards the induction of genes involved in responses to wounding and pathogen attack by chloroplas- tic-produced H202, including indolic glucosinolates-, camalexin-, and stigmasterol-biosynthetic genes. These transcriptional responses were accompanied by the accumulation of 4-methoxy-indol-3-ylmethyl glucosinolate and stigmasterol.