Education
BS, Biology, UNAM, Mexico City
PhD, Biochemistry, UNAM, Mexico City
Post-doc, Plant Molecular Biology, UC San Diego
Description
The main goal of the lab is to understand how plants take up, accumulate and transport trace metals between roots and leaves and from leaves to seeds. Plants and seeds are the main dietary source of essential nutrient metals such as zinc (Zn), iron (Fe), manganese (Mn) and copper (Cu). However, plant-based products are also the main entry point for toxic elements like cadmium (Cd), arsenic (As), mercury (Hg) and lead (Pb). Some of the detrimental effects of heavy metals on human health have been linked to diabetes, hypertension, myocardial infarction, diminished lung function and certain types of cancer.
Understanding the molecular mechanisms by which plants mobilize and accumulate heavy metals will have two major impacts on human health. First, it will enhance the nutritional value and safety of plant products by ensuring the accumulation of essential metals while avoiding the retention of toxic metals. Second, the identification of genes and molecular mechanisms that allow plants to tolerate and accumulate toxic metals will facilitate the engineering of plants for bioremediation purposes.
The David Mendoza lab has three main areas of interest:
- Uptake and allocation of nutrients.
- Plant transcriptional responses to environmental stresses.
- Metabolic engineering.
Long-distance transport of nutrients
Distribution of nutrients between roots and shoots is a dynamic process orchestrated by several plasma membrane transporters, metal-chelating molecules, and vascular loading and unloading processes (Figure 1). Root-to-shoot transport of metals occurs mainly through the xylem; however, due to the limited transpiration rate within reproductive tissues, xylem plays only a minor role in allocating nutrients into the seeds. Phloem transport, on the other hand, plays a key role in delivering nutrients, including metals, to developing seeds. The Mendoza lab is currently focused on the isolation, identification and characterization of phloem transporters of nutrients such as iron (Fe) and zinc (Zn) as well as proteins/peptides mediating the transport and detoxification of toxic elements such as cadmium (Cd) and arsenic (As).
Figure 1 Transporter genes mediating the uptake and allocation of iron (Fe) in Arabidopsis (modified from Mendoza-Cozatl et al., 2019).Plant transcriptional responses to environmental stresses
Plants have evolved a dynamic metabolism to adapt when their environmental conditions change and this may include changes in nutrient availability (Figure 2). To achieve this plasticity, plants need to sense the availability of nutrients in their vicinity and modify their metabolism accordingly. Moreover, it has become clear recently that there is active crosstalk between regulatory networks controlling the uptake and use of different nutrients. This crosstalk is expected as nutrients are incorporated into molecules of diverse composition; however, the molecular and physiological mechanisms behind this crosstalk are still obscure. The Mendoza lab is currently using whole-genome transcriptome and proteomic approaches, combined with high-throughput phenotyping, to uncover the molecular basis of nutrient sensing, nutrient crosstalk and plant adaptation to nutritional deficiencies in several model and crop plants (Figure 3).
Figure 2 Plant adaptation to nutritional deficiencies (modified from Mendoza-Cozatl et al., 2019).
Figure 3 The Mendoza lab works on model plant such as Arabidopsis and crops such as common bean, soybean and rice.Metabolic engineering
The Mendoza lab is also exploring ways to increase the capacity of plants to reduce the accumulation of toxic compounds for better and safer nutrition worldwide. Metabolic engineering, including transporter engineering, requires a clear understanding of the genetic and regulatory processes that define the structure of metabolic pathways and transporter proteins. We are currently using cell- and tissue-specific gene expression to change the allocation of non-essential toxic elements such as Cd and As away from edible plant tissues (e.g. seeds). We are also pursuing gene editing of specific plant transporters to engineer plants more selective for nutrients over non-essential elements. Our research aims to provide a defined strategy to reduce the intake of toxic elements through the consumption of seeds, including grains.
Honors and Awards
2015 CAFNR Early Investigator Researcher Award.
This award is given to junior faculty within CAFNR with a trajectory towards national and international recognition through research, education and contributions to interdisciplinary research team efforts.
2012 NSF Faculty Early Career Development (CAREER) Award.
This is the National Science Foundation’s most prestigious award in support of junior faculty who exemplify the role of teacher-scholars through outstanding research, excellent education and the integration of education and research.
2010 Cozzarelli Prize, National Academy of Sciences, USA.
This award acknowledges papers that reflect scientific excellence and originality and was awarded by the US National Academy of Sciences in the area of Applied Biological, Agricultural, and Environmental Sciences for the discovery of proteins, elusive for more than 15 years, that mediate arsenic tolerance in plants.
2006 PEW Latin American Fellowship in Biomedical Sciences, PEW Foundation.
This award is given to outstanding graduate students to pursue post-doctoral training in the US. Only six fellowships were awarded in 2006 for all Latin American countries.
2005 Weizmann award for the best PhD thesis, nationwide (Mexican Academy of Sciences).
This award recognizes the best PhD thesis in the area of Natural Sciences and is given by the Mexican Academy of Sciences.
U.S. Patents
Lee Y, Martinoia E, Park J, Mendoza-Cozatl D, Schroeder (2013) Composition for phytochelatin transport US 2013 / 0212738 A1 (appl. No. 13/881,671 granted on Aug 2013).
Selected Publications
(5 out 34 peer reviewed publications with 4,239+ citations)
Mendoza-Cózat DG, Gokul A, Carelse MF, Jobe TO, Long TA, Keyster M. (2019) Keep talking: crosstalk between iron and sulfur networks fine-tunes growth and development to promote survival under iron limitations. J Exp Bot. in press (https://doi.org/10.1093/jxb/erz290).
Khan MA, Castro-Guerrero NA, McInturf SA, Nguyen NT, Dame AN, Wang J, Bindbeutel RK, Joshi T, Jurisson SS, Nusinow DA, Mendoza-Cozatl DG. (2018) Changes in iron availability in Arabidopsis are rapidly sensed in the leaf vasculature and impaired sensing leads to opposite transcriptional programs in leaves and roots. Plant Cell Environ. 41:2263-76.
Acosta-Gamboa LM, Liu S, Langley E, Campbell Z, Castro-Guerrero4 NA, Mendoza-Cozatl* DG, Lorence A. (2017) Moderate to severe water limitation differentially affects the phenome and ionome of Arabidopsis. Funct. Plant Biol. 44, 94–106.
Zhang Z, Xie Q, Jobe TO, Kau AR, Wang C, Li Y, Qiu B, Wang Q, Mendoza-Cózatl DG, Schroeder JI (2016). Identification of AtOPT4 as a Plant Glutathione Transporter. Mol Plant. 9:481-4.
Mendoza-Cózatl DG, Xie Q, Akmakjian GZ, Jobe TO, Patel A, Stacey MG, Song L, Demoin DW, Jurisson SS, Stacey G, Schroeder JI. (2014) OPT3 is a component of the iron-signaling network between leaves and roots and misregulation of OPT3 leads to an over-accumulation of cadmium in seeds. Mol Plant. 7:1455-69.
For more publications visit: https://www.ncbi.nlm.nih.gov/pubmed/?term=Mendoza-Cozatl