Maximo L. Rivarola
Member of Dr. Caren Chang’s Laboratory of Molecular Genetics
PhD Candidate, Department of Cell Biology and Molecular Genetics
From: born in Argentina, raised in both Argentina and the U.S.
Education: Master's Degree in Biological Sciences, University of Buenos Aires, Argentina, 2002
Languages: Spanish, English
Interesting Fact: His family owns a ranch in Argentina

As an undergraduate student at the University of Buenos Aires, Maximo Rivarola became interested in basic plant science while researching the genomics of the sunflower. He was motivated by the challenge of deciphering a particular gene’s purpose.

Maximo’s research focuses on understanding the complex ways in which plants respond to internal and external cues such as light, toxins, and hormones. 

Drawn to UM's Strong Reputation in Plant Biology Research

The University of Maryland’s strong reputation in plant biology research drew him to pursue his PhD here, under the direction of Dr. Caren Chang, whose laboratory works with Arabidopsis, a complex flowering plant that is simple to grow and work with. This plant is a solid model for the molecular genetics of all other plants. “The Principal Investigators here at Maryland create a receptive, welcoming, and close knit network that encourages communication and collaboration within and between labs, ” he says.  In addition to the outstanding facilities that the new Bioscience Research Building offers, Maximo also notes the benefits of a diverse graduate community, approachable professors, a weekly plant journal club, monthly ATRIUM and GEMS meetings, and the annual regional Plant Biology Minisymposium that is held here at the University of Maryland.

Understanding How Plants Respond to Stress

Maximo’s research focuses on understanding the complex ways in which plants respond to a vast array of internal and external cues such as light, toxins, and hormones.  He is exploring the ethylene-signaling pathway, which plays an important role in how plants respond by activating gene expression to cope with external stimuli such as a pathogen attack or water stress.  This pathway is of critical importance in the agriculture field where ethylene signaling controls the speed at which tomatoes ripen and the maturation of corn.  Still, some of the components at work in the pathway are not yet fully understood, and this is where Maximo centers his attention.

Deciphering the Precise Role of Genes that the Arabidopsis Plant Shares in Common with Humans

Using the Arabidopsis thaliana plant, whose genome is already sequenced and is easy to transform genetically and pollinate, Maximo’s work focuses on two genes, RTE1 and RTH. He is trying to understand the molecular function of RTE1, the REVERSION-TO-ETHYLENE-SENSITIVITY1 (RTE1) gene, which is a regulator of the ethylene hormone receptor ETHYLENE-RECEPTOR1 (ETR1).

To do this, Maximo engineers different alleles in ETR1 and ERS1 (another ethylene receptor) by in-vitro site directed mutagenesis and then transforms RTE1 knockout plants and examines how these plants differs from a wild-type plant.  Moreover, he examines ETR1 protein levels in different mutants including rte1 null to determine protein stability. He also performs expression studies, looking at what the expression profiles of RTE1 and RTH are under different conditions. Localization studies have led to the finding that RTE1 co-localizes with ETR1.  To characterize the RTE1-HOMOLOG (RTH) gene, Maximo utilizes a knockout of RTH where the gene is engineered to be inoperative, and then grows the plant looking at changes in phenotype. Maximo has been able to present his work in several meetings including one in Shanghai, China and also one in Pisa, Italy where he was invited to give a talk.

The research of these genes provides the foundation for much of the applied science that may help scientists understand the function of RTE1 and RTH, genes that are also found in humans and other animals, and have no known function. The agricultural industry may also benefit from the research on RTE1 since understanding its function may lead to improved ways of controlling the growth environment and shipping procedures for delicate produce. Therefore, Arabidopsis is a great model system to further study RTE function and advance our knowledge of what RTE does in plants and other organisms, including humans.

After Maximo completes his PhD, he is considering changing course by getting into more applied science.  He is also interested in becoming more involved in the science of bioenergy, biodiesel, and/or biofuels. Maximo plans on staying in the College Park area where his family has settled. 

Visit Dr. Caren Chang's website or the Arabidopsis Thaliana Research Initiative at the University of Maryland (ATRIUM) for more information.