Affiliations:

ASU, Joint Appointment: Chemistry and Physics, Arkansas Biosciences Institute

Cluster Identification:
- Comparative Metabolomics Cluster
- Plant Productivity 'Set-Points' Cluster
- Plant Interactions with Other Organisms Cluster

Research Areas/Expertise:
- Abiotic Stress
- Antioxidants
- Gene Regulation & Signal Transduction
- Plant Secondary Metabolism/ Metabolomics/ Metabolic Engineering
- Phytochemicals & Human Health
- Plant Genetics/ Breeding
- Plant Environmental Physiology
- Plant-Made Industrial/ Pharmaceutical Proteins
- Plant Tissue Culture
- Protein Processing & Trafficking
- Transformation Technologies

Research Summary:

The metabolism of aerobic organisms leads to various risks for oxidative damage, due to the formation of reactive oxygen species (ROS). These highly reactive molecules are also formed as a result of abiotic and biotic stress factors. In low amounts ROS play key roles as signaling molecules, however, in excess they cause harmful effects. Plants have developed strategies to keep ROS under control. The ability to detoxify ROS is accomplished in part by vitamin C and glutathione. Plants have evolved at least four different pathways to make vitamin C (a.k.a. ascorbic acid, AsA). These routes use D-mannose/L-galactose, D-galacturonate, L-gulose and myo-inositol as main precursors. 

Lorence and her colleagues at Virginia Tech discovered the inositol pathway to AsA. This route involves four enzymes: myo-inositol oxygenase (MIOX), glucuronate reductase (GlcUR), gluconolactonase (GNL), and L-gulono-1,4-lactone oxidase (GLOase). The Lorence Laboratory uses genetic, biochemical and physiological approaches to study the function of AsA in plant growth, abiotic and biotic stress responses. Our main models of study are Arabidopsis thaliana (mouse ear cress), rice (Oryza sativa) and tomato (Solanum lycopersicum).  Our long term goals are to understand  how the AsA metabolic network is regulated and to study the role of the chloroplastic, ER and mitochondrial subcellular AsA pools in the underlying biochemical mechanisms leading to tolerance to oxidative stress and delayed senescence. A list of ongoing projects is presented below.

Selected Publications:

1.Cruz-Morales S, Castañeda-Gómez J, Figueroa-González G, Mendoza-García AD, Lorence A,  Pereda-Miranda R (2012). Mammalian multidrug resistance lipopentasaccharide inhibitors from Ipomoea alba seeds. Journal of Natural Products.doi.org/10.1021/np300414d

2.Haroldsen V, Chi-Ham CL, Kulkarni S, Lorence A, and Bennet AB (2011) Constitutively expressed DHAR and MDHAR influence fruit, but not foliar ascorbate levels in tomato. Plant Physiology and Biochemistry 49: 1244-1249.

3.Goggin FL, Avila CA, and Lorence A (2010) Vitamin C content in plants is modified by insects and influence susceptibility to herbivory. BioEssays 32: 777-790.

4.Suza WP, Avila CA, Carruthers K, S Kulkarni, Goggin FL, and Lorence A (2010) Exploring the Impact of Wounding and Jasmonates on Ascorbate Metabolism. Plant Physiology and Biochemistry 48: 337-350.

5.Zhang W, Lorence A, Gruszewski HA, Chevone BI and Nessler CL (2009) AMR1, an Arabidopsis gene that coordinately and negatively regulates the mannose/L-galactose ascorbic acid biosynthetic pathway. Plant Physiology 150: 942-950.

6.Lorence A, Mendes P, Chevone BI, and Nessler CL (2004) myo- Inositol Oxygenase Offers a Possible Entry Point into Plant Ascorbate Biosynthesis. Plant Physiology 134: 1200-1205.

Editor of the book: “Recombinant Gene Expression, Reviews and Protocols, Third Edition” (2012) A Lorence (ed.) Molecular Biology Series, Humana/Springer, New York. ISBN # 978-1-61779-432-2, e-ISBN 978-1-61779-433-9, DOI 10.1007/978-1-61779-433-9.

Lab Members:

	Argelia Lorence, PhD, Arkansas Biosciences Institute Associate Professor, Metabolic Engineering; Chemistry and Physics alorence@astate.edu; 870-680-4322
Current Lab Members
	Raquel Torres Research Assistant, ABI raqueltorres123@gmail.com; 870-680-4323
	Siddique Aboobucker PhD student (Molecular Biosciences Program) siddique.aboobucker@smail.astate.edu; 870-680-4323
	Katherine A Lisko PhD student (Molecular Biosciences Program) katherine.lisko@smail.astate.edu; 870-680-4323
	Jonathan A Radin Undergraduate student (Chemistry) jonathan.radin@smail.astate.edu; 870-680-4323
	Satya Veena Tatambhotla Masters student (Biotechnology) satyaveen.tatambho@smail.astate.edu; 870-680-4323
	Jessica Yactayo-Chang PhD Student (Molecular Biosciences Program) jessica.yactayochang@smail.astate.edu; 870-680-4323
Past Students
	Shashank Kulkarni (MS Chemistry) Graduated May 2012 Thesis: Elevating ascorbate content in tomato and studying the role of jasmonates in modulating ascorbate in Arabidopsis" Now: PhD student, Medicinal Chemistry, Northeastern University, August 2012 to date
	Jazmin Martin Undergraduate student (Chemistry) jazmin.martin@smail.astate.edu

Key Collaborators

Dr. Maureen Dolan, research assistant professor | Arkansas State University, Jonesboro
Dr. Fiona L. Goggin, professor | University of Arkansas, Fayetteville
Dr. Kathleen Gilbert, professor | Arkansas Children's Hospital Research Institute and UAMS
Dr. Carole L. Cramer, professor | Arkansas State University, Jonesboro
Dr. Anna Radominska-Pandya, professor | UAMS
Dr. Gregory Phillips, professor | Arkansas State University, Jonesboro
Dr. Anna M. McClung, director | USDA-ARS Dale Bumpers National Rice Research Center 
Dr. Vibha Srivastava, professor | University of Arkansas, Fayetteville
Dr. Carmen M. Gurrola-Diaz, associate professor | Universidad de Guadalajara, Mexico
Dr. Rogelio Pereda-Miranda, professor | Facultad de Quimica-UNAM, Mexico
Dr. Marisa Luisa Villarreal-Ortega, professor | CEIB/UAEM, Mexico
Dr. Rachel Mata, professor | Facultad de Quimica-UNAM, Mexico

Research Projects

1) Study of the role of ascorbate in the control of aging and reproductive activity in plants

2) Metabolic engineering of vitamin C in plants

3) Intersection of ascorbate regulation, jasmonate-signaling, and defense against herbivores in plants (in collaboration with Dr. Fiona Goggin, UA-Fayetteville)

4) Study of the role of ascorbate in mitigating ER and cellular stress associated with plant-based protein production (in collaboration with Dr. Maureen Dolan, ASU)

5) Study of the role of ascorbate at conferring plants tolerance to environmental pollutants (TCE phytoremediation project in collaboration with Dr. Kathleen Gilbert, ACHRI, Dr. Carole Cramer, ASU, and Dr. Anna Radominska-Pandya, UAMS)

6) Vitamin C metabolism in rice (collaboration with Dr. Gregory Phillips, ASU, Dr. Anna McClung, USDA-Stuttgart, AR and Dr. Vibha Srivastava, UA-Fayetteville)

7) Vitamin C metabolism in lupins (collaboration with Dr. Carmen Gurrola-Diaz, Universidad de Guadalajara, Mexico)

8) Vitamin C metabolism in morning glories (collaboration with Dr. Rogelio Pereda-Miranda, Facultad de Química-UNAM, Mexico)

9) Molecular speciation of selected Mexican medicinal plants (collaboration with Dr. Maria Luisa Villarreal CEIB-UAEM, Cuernavaca, Mexico and Dr. Rachel Mata, Facultad de Química-UNAM, Mexico)

Links

http://www.astate.edu/a/abi/people/argelia-lorence.dot

http://evs.astate.edu/Lorence/

http://ittc-web.astate.edu/bio/public/detailed_bio.php?bio_id=556