Day 1 :
United Arab Emirates University, UAE
Keynote: Identification of candidate genes involved in Arabidopsis responses to abiotic and biotic stresses using a transcriptomic approach
Time : 09:30- 10:10
Synan F Abu Qamar has completed his PhD at Purdue University, Department of Botany & Plant Pathology in 2007 and Postdoctoral studies at the same university in the area of Molecular Genetics of Plant Immunity. In August 2008, he joined the Department of Biology at the United Arab Emirates University as an Assistant Professor. Currently, he is an Associate Professor. His current research interest is in the area of Plant Molecular Genetics/Plant Biotechnology. He has co-authored a number of publications in peer-reviewed international journals. He is serving as an Editorial Board Member of reputed journals.
Transcriptional reprogramming forms a major part of a plant’s response to environmental stress. We investigated the effects of combinations of biotic and abiotic stresses on the transcriptome level of Arabidopsis genome using comparative microarrays. We showed a unique program of gene expression was activated in response to each biotic and abiotic stress. In addition, abiotic stress-induced genes were commonly regulated with Botrytis cinerea infection. The Arabidopsis cell wall expansion-like A2 (EXLA2) gene was identified based on its down-regulation in response to infection by the necrotrophic pathogen B. cinerea, and on the reduced susceptibility of its mutants to the same pathogen. The exla2 mutants also enhanced tolerance to the phytoprostane-A1 (PPA1). Our results suggest that the absence or down-regulation of EXLA2 leads to increased resistance to B. cinerea in a COI1-dependent manner, and this down-regulation can be achieved by PPA1 treatment. The EXLA2 is significantly induced by salinity and cold, and exogenous application of abscisic acid (ABA). The exla2 mutant also showed hypersensitivity towards increased salt and cold, and this hypersensitivity required a functional ABA pathway. Overall, EXLA2 appears to be important in response to environmental stress, particularly in the pathogenesis of necrotrophic pathogens and tolerance to abiotic stress. Future directions to further analyze the functions of commonly expressed genes in response to environmental stress will increase our understanding of the plant stress response.
Vytauto Didžiojo universitetas, Lithuania
Keynote: Do riparian species like nitrogen?
Time : 10:10- 10:50
Eugenija Kupcinskiene has been working at Lithuanian University of Agriculture. Currently, she is working in the Department of Biology at Vytautas Magnus University (Kaunas, Lithuania), delivering lectures in multiple courses. Her research experience is obtained by the training at East and West European universities. Research interests extend from ecosystems to Molecular biology, starting from enzymatic DNA methylation. Since 1976 she has been participating in the international scientific events. She is the Author of over two hundred publications. Her current research interests include Natural and Anthropogenic Stress, Oxidative Stress, Allelopathy, Climate Change, Heavy Metal Tolerance, Air Pollutants, Industrial Pollution, Bioindication, Plant Surfaces, Nutrition, Secondary Metabolites of Plants, Invasions, Populations, Plant Molecular Biology and Riparian vegetation.
Statement of the problem: Nitrogen deposition data together with inland water parameters provide message that nitrogen load might affect riparian vegetation of Baltic States. There is much concern about eutrophication of the rivers due to various anthropogenic activities. Depending on species, reaction of plants might encompass a number of different strategies. Plant productivity firstly depends on processes ongoing in the leaves. Studies of riparian plant species usually refer on Ellenberg indicatory values or the other indirect external parameters. Till now data about plant leaf saturation with nitrogen remains poor. Present study is aimed at evaluation of nitrogen concentration among populations of riparian plant species of Lithuania.
Methodology and Theoretical orientation: Both, widely spread native and invasive species were selected (Figure). Depending on frequency of species occurrence, populations were sampled along main river basins in Lithuania: Nemunas, Venta, Lielupe, Baltic Seafront. Material was collected in 230 sites. Only leaf blades were used for analyses. Nitrogen concentration was determined by Kjeldahl method (project sponsored by Lithuania Research Council; SIT-02/2015). Nitrogen concentration data were related to the land use type (employing CORINE classification system), river size, intensity of agriculture, fragments of the rivers differing in their nature (natural or regulated).
Findings: Differencies in leaf nitrogen concentrations between populations were the smallest for Stuckenia pectinata and the largest for Lythrum salicaria. Leaf nitrogen concentration of selected species was not influenced by regulations in some rivers also did not depend on river size.
Conclusion and Significance: Among the tested plants the highest concentration was detected for invasive in Lithuania species Echinocystis lobata. It could be concluded that present level of nitrogen amounts, entering riparian ecosystems is big enough to cause spread of nitrophilous species.
RIKEN Center for Sustainable Resource Science, Japan
Keynote: Cesium is a specific inhibitor of the AKT1-KC1 complex-mediated potassium influx in Arabidopsis
Time : 11:10-11:50
Ryoung Shin, PhD is a Unit Leader and the Principal Investigator of Regulatory Network Research Unit, RIKEN Center for Sustainable Resource Science. She had worked on the molecular mechanisms of virus resistance in hot pepper and earned her PhD at Korea University in 2002. She moved to USA for her Postdoc Fellow and started to research on potassium sensing and signaling in plants at Donald Danforth Plant Science Center, St. Louis, USA. In 2008, she became the Unit Leader at RIKEN and continued to work on plant potassium deficiency signaling. Recently, her team expanded the research to radiocesium remediation after the accident at the Fukushima Nuclear Power Plant in Japan following the great earthquake in 2011 caused the spread of radiocesium over the surrounding areas.
Cesium (Cs+) exists in nature at relatively low levels but occasionally accidental anthropogenic activities spread high levels of Cs+ (most commonly radioactive) which contaminate the environment and enter the food chain. Cs+ disrupts plant growth at high concentrations through pleiotropic effects and the part of the Cs+ toxicity in plants is known to derive from competition and interference with potassium (K+) due to the similarity in physicochemical properties between K+ and Cs+. K+ is an essential nutrient, a lack of which causes serious growth retardation and physiological defects. In order to find the means to sustain plant growth in Cs+-contaminated areas for phytoremediation purpose, the molecular mechanisms of how Cs+ exerts its deleterious effects on K+ accumulation in plants need to be elucidated. In Arabidopsis thaliana, K+ uptake through the roots is considered to be mediated mainly by two players: Arabidopsis K+ Transporter 1 (AKT1) and High Affinity K+ Transporter 5 (HAK5). Expression of HAK5 is swiftly induced in response to K+ deficiency while AKT1 is more responsible for low-affinity K+ uptake. AKT1 forms a tetrameric complex with K+ Rectifying Channel 1 (KC1) to exert proper function. Here, we show that mutation on a member of the major K+ channel AKT1-KC1 complex renders Arabidopsis thaliana hypersensitive to Cs+. Electrophysiological analysis demonstrated that Cs+, but not sodium, rubidium or ammonium, specifically inhibited K+ influx through the AKT1-KC1 complex. In addition, a lack of KC1 further led to an inability of Arabidopsis to accumulate K+ in the plant body due to uncontrollable K+ leakage through the homomeric AKT1 channel. These data indicate that Cs+ is a specific inhibitor of the AKT1 complex-mediated K+ influx and KC1 is essential to avoid K+ leakage.