2nd Global Summit on Plant Science October 06-08, 2016 Hilton London Heathrow Airport, UK

Biography:

Dr. Rose earned his bachelor’s degree at the University of Manchester, UK, and then worked for a biotechnology company, before relocating to the USA. He was awarded a Ph.D. from the University of California Davis, and received his postdoctoral training at the University of Georgia. He accepted a faculty position in the Department of Plant Biology, Cornell University. Dr. Rose is also the Director of Cornell’s Institute of Biotechnology and Director of the New York State Center for Life Sciences Enterprise. He is an elected Fellow of the American Association for the Advancement of Science.

Abstract:

Most biochemical and molecular studies involving the extraction of transcripts or proteins from plant organs use a homogenized amalgam of tissues and cell types. This approach limits insights into cell specialization, and lower abundance molecules that are present only in certain cell types are often diluted below the level of detection. There is therefore a critical ‘information void’ when it comes to annotating and presenting gene expression data. We have been addressing this challenge in the context of understanding the entirety of gene expression during tomato fruit development, by coupling RNA-seq analysis with laser capture microdissection (LCM), which allows the precise isolation of individual fruit cells/tissue types. In addition to resolving gene expression down to the level of cell/ tissue type, this approach has enabled: (i) the identification of previously unannotated genes, demonstrating the value of LCM as a tool for gene discovery; (ii) inferences regarding gene functions, based on the patterns of tissue- or cell type-related expression. We have also been developing computed tomography as a non-invasive imaging tool to create a 3D ‘virtual tomato’, which includes internal structures, to provide digital a scaffold upon which to present transcriptome, or other ‘omics’ data sets as a 4D display. All data will be publicly accessible in a new database, the Tomato Expression Atlas. This database includes a novel user interface with a correlation matrix that reveals patterns of co-expressed genes at an unprecedented level of spatiotemporal resolution, thereby optimizing the identification of functionally related suites of genes.

Biography:

Gunnar Wingsle has completed his PhD at the age of 34 years from Department of Forest Genetics & Plant Physiology. He has published more than 60 papers in reputed journals and has been serving as a PI of the proteomic masspectrometry facility at Chemical Biological Centre at Umeå University and SLU since 2000

Abstract:

Wood development is of outstanding interest for both the basic research and industry due to the associated cellulose and lignin biomass production. Efforts to elucidate wood formation (which is essential for numerous aspects of both pure and applied plant science) have mostly been made using different -omic analyses from low resolution samples. In our studies we analyzed the global protein expression in different cell types originating from phloem, cambium and xylem in wood from Populus. However, we have also to a minor degree; used spruce has a model system. These cell types represent distinct developmental stages and, therefore, could help to explain cellular mechanisms of developmental processes such as xylogenesis and the phenomenon of wood formation. To additionally add information of wood related developmental questions we have applied different stress conditions as gravitational stress, resulting in tension wood, and oxidative stress caused by antisense-transgenic plants of an isoform of superoxide dismutase (hiPI-SOD). Data from multiple platforms including transcriptomics (microarray analysis), proteomics (UPLC/QTOF-MS), and metabolomics (GC-TOF/MS, UPLC/MS, and UHPLC-LTQ/MS) were integrated using recent development of orthogonal projections to latent structures called OnPLS. Furthermore, global and targeted proteomic studies have been done of whole cell extracts and subcellular fractions to give a more specific and sensitive analysis of wood development proteins, such as cellulose synthase proteins (CES).

Biography:

Robert L. Brown completed his PhD in Plant Pathology from Rutgers University and postdoctoral studies from Southern Regional Research Center (SRRC), USDA-ARS in New Orleans, Louisiana. He is employed as a research plant pathologist in the Food and Feed Safety Research Unit at SRRC and also holds appointments as Adjunct Associate Professor at both Louisiana State University and Southern Illinois University-Carbondale. He is an editorial board member for several journals and has published over 110 research, review and proceedings papers, and book chapters, and over 160 abstracts.

Abstract:

Aflatoxin are secondary metabolites produced by the fungus Aspergillus flavus that can contaminate maize, and cause toxic and carcinogenic effects in higher organisms that consume the contaminated commodities. Therefore, aflatoxin contamination of maize is a serious food safety problem that affects the competitiveness of agricultural production in both domestic and export markets. Post-harvest management of these toxins is only marginally effective. Therefore, pre-harvest control of aflatoxin contamination, especially through host resistance, is a desirable goal. A research collaboration between the International Institute of Tropical Agriculture (IITA), Ibadan, Nigeria and the USDA-ARS in New Orleans developed six aflatoxin-resistant maize inbreds that are currently being used by national programs in Africa and which have demonstrated resistance in U.S. environments. To investigate the mechanisms responsible for resistance and identify breeding markers for commercial development of these lines several studies have been undertaken. Implicated in resistance is marked accumulation of constitutive proteins. Comparative proteomics identified constitutive resistance-associated proteins (RAPs) belonging to either antifungal, stress-related or storage categories. The potential of selected RAPs as resistance genes was further highlighted in characterization studies. The importance of constitutive accumulation of resistance factors was also supported by a microarray investigation of two closely-related maize lines varying in aflatoxin accumulation and demonstrating a ten-fold difference in the number of induced genes between the resistant and susceptible genotype. To discover target genes for enhancing resistance in maize, RNA-Seq is being employed to investigate gene expressionnetwork differences in defense response between resistant and susceptible kernels.

Biography:

A.A. Ivlev has completed his PhD at the age of 27 years from Chemical Technology University of D.I. Mendeleev. and got his 2-nd PhD from Institute of Chemical Physics of RAS. In 2005 he has discovered a link between carbon isotope distribution and temporal organization of cell processes and was awarded with medal “To Author of Scientific Discovery” by Russian Academy of Natural Sciences. Since 1995 he is Professor of Russian State Agrarian University of K,A. Timiryazev. He has published 66 papers in reputed journals and 4 monographs. The field of his scientific interests includes isotope fractionation in metabolism, photosynthesis, plant physiology, cell mechanisms, evolution, climatology.

Abstract:

The combination of actualism principle, recent findings on carbon isotope fractionation in photosynthesis with data on isotopic ratio of carbon in sedimentary rocks in form of carbonates and coeval organic matter allowed suggesting a new model of redox carbon cycle. the model claims that carbon turnover via biosphere and geospheres is a conversion of the element from the oxidized state to the reduced one, and back. the direct transfer is realized through photosynthesis, the reverse transfer occurs via numerous microbial and inorganic oxidation reactions in sediments. among them thermochemical sulfate reduction plays a dominant role. it proceeds in subduction zone where moving lithospheric plates collide and provide heat for sulfate reduction. co2 injections, which accompany the reaction, exert impact on photosynthesis development, causing irregular periodicity of photosynthesis and related processes, such as climatic cycles, changes in the rate of biodiversity, uneven stratigraphic distribution of organic matter in sediments, and oil fields stratigraphic distribution, sea level changes, etc. arguments supporting the validity of the model are given. the redox carbon cycle is a self-organizing system due to negative feedback between co2 assimilation and photorespiration in response to oxygen growth. it made carbon cycle shift to ecological compensation point. in this point the system become sensitive to separate plates’ collisions what results in short-term climatic oscillations.

Biography:

Kevin Yueju Wang has completed his PhD in 2004 from at the Oregon State University, USA. He had postdoctoral experiences from the University of California at Berkley and the University of Texas at Austin. He was appointed as an tenured Associate Professor in Molecular Biology at the Northeastern State University in August 2015. He has a broad background in plant molecular biology and biotechnology, with specific training and expertise in expression of genes in plants to produce therapeutic proteins that are active, safe and inexpensive.

Abstract:

Stroke has remained the top major killer worldwide. It is also the leading cause of adult disability. Recombinant human tissue plasminogen (rt-PA) is the only FDA-approved treatment for acute ischemic stroke. The yields of rt-PA protein produced from CHO cells, however, are, at present, relatively low while the cost of production is high. It often causes side effects which may lead to disability and death. Vampire bat (Desmodus rotundus) salivary plasminogen activators (DSPA1) have been found to be both more active than t-PA and to have fewer side effects. In this study, both DSPA1 and t-PA were targeted in tobacco seed under seed-specific promoter (phas) to minimize protein degradation. Both t-PA and DSPA1 were codon-optimized for tobacco plant usage to increase foreign protein expression level. 6xHis tag was fused to C-terminal for recombinant protein purification. The ER signal peptide sequence, KDEL, will be used to accumulate recombinant proteins to the ER. The geminivirus-based single DNA replicon system (pBY was used to rapidly produce t-PA and DSPA1, respectively in tobacco leaf. Studies showed that recombinant proteins caused leaf tissue death. Seed-derived proteins can dissolve fibrin and human blood clots. Our study demonstrated that seed-based system can rapidly produce functional recombinant t-PA and DSPA1 for stroke patient treatment. This work was supported by the National Institute of General Medical Sciences of the National Institutes of Health (8P20GM103447) and National Institute of Neurological Disorders and Strokes (1R03NS095246-01).

Biography:

Somika Bhatnagar has completed her PhD in 2003 from University of Delhi, South Campus, India and postdoctoral research at Temasek Life Sciences Laboratories, Singapore. She is currently HEAD of PLANT TRANSFORMATION and TISSUE CULTURE at Temasek Life Sciences Laboratories, Singapore. Her research work has been patented and published in many peer reviewed journals. It has also led to a spin-off company (Bioforest Private Limited, Singapore). Her interests include translational plant research areas like biotech crop development, forestry biotechnology, herbal medicine with special focus on conservation and large scale sustainable production of useful compounds both in vitro and in vivo.

Abstract:

Plants have been historically used as a renewable source for bioactive compounds in traditional therapeutic regimens such as Ayurveda in India and Traditional Chinese Medicine. With the increase in population, globalization and economic development, there is also persistent demand for natural products including secondary metabolites which are economically important as drugs, flavor and fragrances, dye and pigments, pesticides, and food additives. Supply of these compounds from natural bio resources proves to be a challenge because of depleting natural plant populations, low yields, slow rate and seasonal variability in accumulation of desirable compounds. Natural compounds are difficult to produce through chemical synthesis due to their complex structures and high cost of production. Plant biotechnology has shown potential as an alternative way for production of bioactive compounds in in vitro systems independent of climate, soil and plant growth conditions. We have developed callus, shoot and hairy root culture systems for seven plant species. Bioactive compounds belonging to sesquiterpenes, phenyethyl chromone derivatives, flavanoids and fatty acids groups are identified using GC-MS analysis. Addition of abiotic and biotic elicitors to the culture medium enhanced production of these secondary metabolites. Some compounds from these plants of interest are Aquilaria crassna (Guai 1(10),11-diene, beta-Eudesmol, Humulene), Melia dubia (Aromandendrene, Germacrene, Copaene), Syzygium aromaticum (Eugenol which can further be converted to Vanillin), Morus indica (Megastigmane), Artemisia pallen (Devanone), Pelargonium citrosum (Geraniol, Linalol, Citronella) and Phlegmariurus phlegmaria (Huperzine A). Efforts are underway towards commercial scale production of these compounds, elucidation of biosynthetic pathways and characterization of genes involved in secondary metabolite production.

Biography:

Dr. Teresa Hernández Sotomayor undertook her undergraduate, master's and doctorate studies at the National Autonomous University of Mexico (UNAM). She joined the Scientific Research Centre of Yucatán (CICY) in July 1993. Dr. Hernádez's research has focused on the study of the mechanisms of signal transduction in plant cells. She has written over 80 international articles. Dr. Hernández's work has been cited by authors over 1,500 times. Her current research is the study of the basic mechanisms of signal transduction which is fundamental to solving problems such as for many pests and diseases that limit the performance of important cultivars such as rice, sorghum and wheat. The work of Dr. Hernandez in this aspect is important for Mexico's Southeast region.

Abstract:

Aluminium (Al) is the most abundant metal on Earth’s crust (7% of the all elements). Toxicity due to this metal is widely documented in tropical acid mineral soils and is the major factor limiting over the productivity of crop species. Coffee is one of the most important crops economically worldwide. This crop grows on acid soils where the availability of Al is greater; therefore coffee yield is limited by the toxic effects of this element. We have developed a biological model in which suspension cells of Coffea arabica have been used. We found that aluminium toxicity affect the activity of different enzymes involved in the metabolism of phosphoinositides and other members of the signal transduction pathway associated to them. We also are looking for the effect of salicylic acid and the mechanism of protection in aluminium toxicity on this signal transduction mechanism. An overview of the latest results will be presented.

Biography:

Dr Chaturvedi, Professor of Plant Biotechnology at BSBE Department, is the Associate Dean of Alumni & External Relations. She was Vice-Chairperson of All India examinations of Graduate Aptitude Test in Engineering (GATE) and Joint Admission Test for M.Sc. (JAM) 2013, Chairperson GATE-JAM 2014, Chairperson GATE-2015 and Organizing Chairperson JAM-2015 examinations.

Her research area is 'Plant Tissue Culture & Metabolite Production'. She received ‘Prof Y.S. Murty Gold Medal-2011’ by Indian Botanical Society (IBS) and member of National Academy of Sciences, India (NASI) and Society for In vitro Biology (SIVB), USA. She is Associate Editor of “In Vitro - Plant” of Springer.

Abstract:

The unique capacity of plant cells has found many applications in plant improvement, propagation, conservation and in other basic & applied plant sciences. The tissue culture technique would not only surmount the limitations of vegetative propagation but also can hasten the production of clonal material for field planting. It offers many advantages over the conventional methods of vegetative propagation: (1) The rate of multiplication is extremely rapid and can continue round the year, independent of the season. Thus, over a million plants can be produced in a year starting from a small piece of tissue. (2) The enhanced rate of multiplication can considerably reduce the period between the selection of plus trees and raising enough planting material for field trials.

The other application of tissue culture is the production of haploid plants which are extremely valuable in plant breeding and genetics. As with haploids, homozygosity can be achieved in a single step otherwise obtaining homozygous lines of woody perennials by the conventional method of recurrent inbreeding is impractical and time consuming because of highly heterozygous nature and long generation cycle of these plants as well as inherent inbreeding depression. The technique can further be used to produce bioactive metabolites in bulk irrespective of seasons and regions. To channelize the output obtained on laboratory scale more efforts are required in right direction to make the results more viable and of use to the general public.

Biography:

Doaa Elazab, corresponding author has completed her PhD from Assiut University in plant tissue culture and abiotic stress, and postdoctoral studies from McGill University, Plant science Dept., Canada, she got training on HPLC. She published many papers about plant tissue culture, plant molecular analysis and biotic and abiotic stress on fruit trees

Abstract:

This current study investigated the influence of medium type and Indole Acetic Acid (IAA) concentration on artificial seed germination and growth in Zizyphus Spina-Christie (Napq tree), four types of media ((Murashigi and Skoog, Nitsch and Nitsch, Woody and Gamborg) and five concentrations of IAA (0.0, 0.05, 0.1, 0.5, 1.0 and 1.5 mg/l) were used. Data indicated that, IAA at 0.1 mg/l was found to be the best concentration to germinate the synthetic seeds by 86.67% germination; the second best one was 0.5 mg/l with 3.33% germination. MS medium was the best medium in shoot height (cm), leaves and nodes number and leaves dimensions (cm) compared to NN, WPM and B5 media. On the other hand, MS medium supplemented with 0.1 mg/L IAA were the best in germination and vegetative characteristics in synthetic seeds of Hozaien nabq.

Biography:

Caroline Janitz is a Manager of the Next-Generation Sequencing Facility at Western Sydney University, Australia. Along with supervising her team, she is responsible for both the development and implementation of technological improvements in the NGS pipeline. She has completed her PhD in Molecular Genetics from the Freie Universität Berlin, Germany, under the supervision of Prof. Hans Lehrach, Director of the Max Planck Institute for Molecular Genetics in Berlin. Her PhD thesis focused on “An investigation of the molecular mechanism of renal damage in the course of rat hypertension using laser micro dissection and Affymetrix gene expression profiling”.

Abstract:

The strand-specific RNA-Seq has been broadly utilized for comprehensive transcriptome surveys, including transcripts orientation and information, which is inaccessible when using conventional RNA-Seq. To retain the strand-specificity, it is highly recommended to remove genomic DNA from the RNA template. Despite current availability of improved DNase treatment protocols, removal of genomic DNA remains a technical challenge. This step in sample preparation is particularly difficult when dealing with samples with extremely low RNA concentrations. Moreover, DNase digestion demands additional purification step, which leads to loss of up to 30% of RNA template. Therefore a question arises whether an additional step of genomic DNA removal is essential. In order to address the impact of genomic DNA contamination on strand-specificity resolution, we used a tobacco model N. benthamiana that was depleted in ribonuclease J and essential for chloroplast RNA surveillance. Depletion of this RNase J results in massive accumulation of chloroplast antisense RNA. In this talk, I am going to present results of our analysis of changes in expression levels of reference sense and anti-sense transcripts in relation to degree of the RNA sample contamination with genomic DNA.

Biography:

Synan F AbuQamar completed his PhD from Purdue University in Department of Botany & Plant Pathology in 2007 and Post-doctoral 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 at Arab Emirates University. His current research interest is in the area of Plant Molecular Genetics/Plant Biotechnology. He is co-author of number of publications in peer-reviewed international journals and serves as an Editorial Board Member in reputed journals.

Abstract:

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 expansin-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.

Biography:

Sedigheh Esmaeilzadeh Bahabadi has completed his PhD at the age of 29 years from Tarbiat Modares University, Iran and was researcher at SUNBOR Institute, Japan and Göttingen University, Germany. She is Assistant Professor, Department of Biology, University of Zabol, Iran. She is published more than 10 papers in reputed journals and has been serving as a reviewer of international journals.

Abstract:

Pharmaceutically significant secondary metabolites include alkaloids, lignans, glycosides, flavonoids, volatile oils, etc. Currently, most of these secondary metabolites are isolated from wild or cultivated plants because their chemical synthesis is either extremely difficult or economically infeasible. Plant in vitro cultures represent an renewable source of valuable medicinal compounds and cost-effective alternative to classical approaches to plant secondary metabolite production. Numerous strategies have been developed to improve the productivity of plant culture such as medium optimization, precursor addition, elicitation, genetic transformation, metabolic engineering

Elicitation is a good strategy to induce physiological changes and stimulate defense or stress-induced. Traditionally, elicitors have been classified in two types, abiotic or biotic, according to their chemical nature and exogenous or endogenous origin. Here, we summarize the enhancing effects of elicitors on the production of bioactive compounds such as alkaloids, lignans, volatile oils, focusing particularly on the use of biotic elicitors, salicylic acid and nitric oxide. Understanding how plant tissues and their specific secondary metabolic pathways respond to specific treatments with elicitors would be the basis for designing protocols to enhance the production of secondary metabolites, in order to produce quality and healthy fresh foods.

Biography:

B.P. Tripathi has completed his Ph.D. at the age of 50 years from the University of Philippines, Los, Banos, Philippines. He is the Senior Associate Scientist in the International Rice Research Institute (IRRI), Philippines based in Nepal. He hs published more than 20 papers in reputed journals and has been serving as an editorial board member of Nepalese Journals of Agriculture.

Abstract:

Rice is the principal food grain crop in Nepal followed by maize and wheat. The total area of Nepal is approximately 1.5 million ha with the average productivity of 3.2 t/ha producing  4.8 million tons of paddy rice. Nepal Agricultural Research Council (NARC) is the sole public organization in Nepal that conducts rice research in the country.   Rice research in NARC is coordinated and implemented by National Rice Research Program (NRRP), Hardinath, Dhanusha District in coordination with Regional Agricultural Research Stations (RARS) and Central Disciplinary Divisions, Kathamandu.  Department of Agriculture (doA) under the Ministry of Agricultural development (MoAD) is responsible to disseminate rice technologies to farmers’ fields.

Presently, the investment in rice research is very low in Nepal with less than 0.1% of the value of rice output being invested in rice research. Rice research program in NARC also receives less share of the agricultural research budget (only 4% of the total research budget) despite the vital share of rice output (20%) in national Agriculture Gross Domestic Product (AGDP). In the past five decades, rice production in Nepal increased nearly 2.2 times from 2.1 million tons in 1961-63 to 4.8 million tons in 2010-15.  During the same period, rice production grew at the rate of 1.8% per annum which was below the population growth rate of 2.3% per annum. As a result, the rice self sufficiency ratio declined significantly over time. In recent years, the rice self sufficiency ratio is below 100, which means domestic rice production is not sufficient to meet the domestic consumption.

The production condition of cereals is also almost same to that of rice. The data for 2001-2008 shows that Nepal is the only South Asian country where the growth rate of cereal production trails behind the growth rate of population (Figure 5). Consequently Nepal’s domestic production has not been able to fulfill local demand and the country has been a net importer of cereals since the 1980s. Despite slow growth in cereals output, per capita availability of cereals in Nepal is second highest in South Asia due to the food imports especially across the open border with India. Even though Nepal has a relatively high per capita cereal supply, the low income levels is a constraint for adequate food consumption by a large section of the population (IFPRI, 2010).

Irrigated rice accounts for 56% of the total rice area in Nepal. Thus, large rice production still occurs under rainfed condition. Based on the average per capita milled rice consumption of 122 kg per yea and total population of 27.6 million, the total demand for milled rice in Nepal is estimated at 3.37 million tons (5.04 million tons of paddy) in 2012. But the country produced only 2.97 million tons milled rice (4.50 million tons paddy). Assuming that only 80% of total harvest is available for human consumption, the total milled rice produced in the country available for consumption is only 2.38 million tons (3.60 million tons of paddy). This means the country has a shortfall of about 1 million tons of milled rice (1.5 million tons paddy).

In addition to the population growth, income growth also creates additional demand for rice. The current demand for rice may be low due to low levels of income. As income rises, the demand for rice can be expected to increase as rice substitutes for coarse grains that are currently being consumed. In addition, as the country marches towards improved governance, economic growth, and infrastructure development, the food habit likely to change in favor of rice which would increase rice demand. Infrastructure development particularly increased road access to remote hills and mountains will increase demand for rice substantially due to availability of rice in cheaper price.

The following major constraints to rice production in Nepal are included: (a) land constraints, (b) large yield gaps, (c) inappropriate technologies especially in rainfed areas, (d)problems of product quality and timely delivery of inputs (e) limited access to new technology and inefficient technology transfer, and  (f) inadequate policy support. Therefore, the priority rice research and development agenda for Nepal, are discussed as: development and promotion of high yielding, stresses tolerant and better grain quality rice varieties, integrated crop and resource management for sustainable rice production, development and promotion of small-scale mechanization and post harvest technologies, socioeconomic and policy research to craft farmer-friendly policies, investment in rice research and extension, and capacity building in strategic frontier areas of rice research.

Biography:

Robert L. Brown completed his PhD in Plant Pathology from Rutgers University and postdoctoral studies from Southern Regional Research Center (SRRC), USDA-ARS in New Orleans, Louisiana. He is employed as a research plant pathologist in the Food and Feed Safety Research Unit at SRRC and also holds appointments as Adjunct Associate Professor at both Louisiana State University and Southern Illinois University-Carbondale. He is an editorial board member for several journals and has published over 110 research, review and proceedings papers, and book chapters, and over 160 abstracts.

Abstract:

Aflatoxin are secondary metabolites produced by the fungus Aspergillus flavus that can contaminate maize, and cause toxic and carcinogenic effects in higher organisms that consume the contaminated commodities. Therefore, aflatoxin contamination of maize is a serious food safety problem that affects the competitiveness of agricultural production in both domestic and export markets. Post-harvest management of these toxins is only marginally effective. Therefore, pre-harvest control of aflatoxin contamination, especially through host resistance, is a desirable goal. A research collaboration between the International Institute of Tropical Agriculture (IITA), Ibadan, Nigeria and the USDA-ARS in New Orleans developed six aflatoxin-resistant maize inbreds that are currently being used by national programs in Africa and which have demonstrated resistance in U.S. environments. To investigate the mechanisms responsible for resistance and identify breeding markers for commercial development of these lines several studies have been undertaken. Implicated in resistance is marked accumulation of constitutive proteins. Comparative proteomics identified constitutive resistance-associated proteins (RAPs) belonging to either antifungal, stress-related or storage categories. The potential of selected RAPs as resistance genes was further highlighted in characterization studies. The importance of constitutive accumulation of resistance factors was also supported by a microarray investigation of two closely-related maize lines varying in aflatoxin accumulation and demonstrating a ten-fold difference in the number of induced genes between the resistant and susceptible genotype. To discover target genes for enhancing resistance in maize, RNA-Seq is being employed to investigate gene expression network differences in defense response between resistant and susceptible kernels.

Biography:

Synan F AbuQamar completed his PhD from Purdue University in Department of Botany & Plant Pathology in 2007 and Post-doctoral 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 at Arab Emirates University. His current research interest is in the area of Plant Molecular Genetics/Plant Biotechnology. He is co-author of number of publications in peer-reviewed international journals and serves as an Editorial Board Member in reputed journals.

Abstract:

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 expansin-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.