Honors & Awards
Best Talk Award - 2nd place, Carnegie Institution for Science - Department of Plant Biology (2014)
Emerging Scientist Award - Graduate Student, 25th International Conference on Ara- bidopsis Research (ICAR) (2014)
Hoefer Prize for excellence in mentoring undergraduate writing, Stanford University (2014)
Excellence in Teaching Award, Department of Biology - Stanford University (2013)
Bacharel, Universidade De Sao Paulo (2009)
Doctor of Philosophy, Stanford University, BIO-PHD (2016)
Dominique Bergmann, Postdoctoral Faculty Sponsor
Transcriptome Dynamics of the Stomatal Lineage: Birth, Amplification, and Termination of a Self-Renewing Population
2015; 33 (1): 107-118
Developmental transitions can be described in terms of morphology and the roles of individual genes, but also in terms of global transcriptional and epigenetic changes. Temporal dissections of transcriptome changes, however, are rare for intact, developing tissues. We used RNA sequencing and microarray platforms to quantify gene expression from labeled cells isolated by fluorescence-activated cell sorting to generate cell-type-specific transcriptomes during development of an adult stem-cell lineage in the Arabidopsis leaf. We show that regulatory modules in this early lineage link cell types that had previously been considered to be under separate control and provide evidence for recruitment of individual members of gene families for different developmental decisions. Because stomata are physiologically important and because stomatal lineage cells exhibit exemplary division, cell fate, and cell signaling behaviors, this dataset serves as a valuable resource for further investigations of fundamental developmental processes.
View details for DOI 10.1016/j.devcel.2015.01.025
View details for Web of Science ID 000352454200011
View details for PubMedID 25850675
- Irreversible fate commitment in the Arabidopsis stomatal lineage requires a FAMA and RETINOBLASTOMA-RELATED module ELIFE 2014; 3
Convergence of stem cell behaviors and genetic regulation between animals and plants: insights from the Arabidopsis thaliana stomatal lineage.
2014; 6: 53-?
Plants and animals are two successful, but vastly different, forms of complex multicellular life. In the 1600 million years since they shared a common unicellular ancestor, representatives of these kingdoms have had ample time to devise unique strategies for building and maintaining themselves, yet they have both developed self-renewing stem cell populations. Using the cellular behaviors and the genetic control of stomatal lineage of Arabidopsis as a focal point, we find current data suggests convergence of stem cell regulation at developmental and molecular levels. Comparative studies between evolutionary distant groups, therefore, have the power to reveal the logic behind stem cell behaviors and benefit both human regenerative medicine and plant biomass production.
View details for DOI 10.12703/P6-53
View details for PubMedID 25184043
Irreversible fate commitment in the Arabidopsis stomatal lineage requires a FAMA and RETINOBLASTOMA-RELATED module.
The presumed totipotency of plant cells leads to questions about how specific stem cell lineages and terminal fates could be established. In the Arabidopsis stomatal lineage, a transient self-renewing phase creates precursors that differentiate into one of two epidermal cell types, guard cells or pavement cells. We found that irreversible differentiation of guard cells involves RETINOBLASTOMA-RELATED (RBR) recruitment to regulatory regions of master regulators of stomatal initiation, facilitated through interaction with a terminal stomatal lineage transcription factor, FAMA. Disrupting physical interactions between FAMA and RBR preferentially reveals the role of RBR in enforcing fate commitment over its role in cell-cycle control in this developmental context. Analysis of the phenotypes linked to the modulation of FAMA and RBR sheds new light on the way iterative divisions and terminal differentiation are coordinately regulated in a plant stem-cell lineage.
View details for DOI 10.7554/eLife.03271
View details for PubMedID 25303364
Sugarwin: A Sugarcane Insect-Induced Gene with Antipathogenic Activity
MOLECULAR PLANT-MICROBE INTERACTIONS
2012; 25 (5): 613-624
In sugarcane fields, colonization of the stalk by opportunistic fungi usually occurs after the caterpillar Diatraea saccharalis attacks the sugarcane plant. Plants respond to insect attack by inducing and accumulating a large set of defense proteins. Two homologues of a barley wound-inducible protein (BARWIN), sugarcane wound-inducible proteins SUGARWIN1 and SUGARWIN2, have been identified in sugarcane by an in silico analysis. Antifungal properties have been described for a number of BARWIN homologues. We report that a SUGARWIN::green fluorescent protein fusion protein is located in the endoplasmic reticulum and in the extracellular space of sugarcane plants. The induction of sugarwin transcripts occurs in response to mechanical wounding, D. saccharalis damage, and methyl jasmonate treatment. The accumulation of transcripts is late induced and is restricted to the site of the wound. Although the transcripts of sugarwin genes were strongly increased following insect attack, the protein itself did not show any effect on insect development; rather, it altered fungal morphology, leading to the apoptosis of the germlings. These results suggest that, in the course of evolution, sugarwin-encoding genes were recruited by sugarcane due to their antipathogenic activity. We rationalize that sugarcane is able to induce sugarwin gene expression in response to D. saccharalis feeding as a concerted plant response to the anticipated invasion by the fungi that typically penetrate the plant stalk after insect damage.
View details for DOI 10.1094/MPMI-09-11-0254
View details for Web of Science ID 000303083000002
View details for PubMedID 22250584
SacRALF1, a peptide signal from the grass sugarcane (Saccharum spp.), is potentially involved in the regulation of tissue expansion
PLANT MOLECULAR BIOLOGY
2010; 73 (3): 271-281
Rapid alkalinization factor (RALF) is part of a growing family of small peptides with hormone characteristics in plants. Initially isolated from leaves of tobacco plants, RALF peptides can be found throughout the plant kingdom and they are expressed ubiquitously in plants. We took advantage of the small gene family size of RALF genes in sugarcane and the ordered cellular growth of the grass sugarcane leaves to gain information about the function of RALF peptides in plants. Here we report the isolation of two RALF peptides from leaves of sugarcane plants using the alkalinization assay. SacRALF1 was the most abundant and, when added to culture media, inhibited growth of microcalli derived from cell suspension cultures at concentrations as low as 0.1 microM. Microcalli exposed to exogenous SacRALF1 for 5 days showed a reduced number of elongated cells. Only four copies of SacRALF genes were found in sugarcane plants. All four SacRALF genes are highly expressed in young and expanding leaves and show a low or undetectable level of expression in expanded leaves. In half-emerged leaf blades, SacRALF transcripts were found at high levels at the basal portion of the leaf and at low levels at the apical portion. Gene expression analyzes localize SacRALF genes in elongation zones of roots and leaves. Mature leaves, which are devoid of expanding cells, do not show considerable expression of SacRALF genes. Our findings are consistent with SacRALF genes playing a role in plant development potentially regulating tissue expansion.
View details for DOI 10.1007/s11103-010-9613-8
View details for Web of Science ID 000276911800003
View details for PubMedID 20148351
A conserved dibasic site is essential for correct processing of the peptide hormone AtRALF1 in Arabidopsis thaliana
2008; 582 (23-24): 3343-3347
Prohormone proteins in animals and yeast are typically processed at dibasic sites by convertases. Propeptide hormones are also found in plants but little is known about processing. We show for the first time that a dibasic site upstream of a plant peptide hormone, AtRALF1, is essential for processing. Overexpression of preproAtRALF1 causes semi-dwarfism whereas overexpression of preproAtRALF1(R69A), the propeptide with a mutation in the dibasic site, shows a normal phenotype. RALF1(R69A) plants accumulate only the mutated proprotein and not the processed peptide. In vitro processing using microsomal fractions suggests that processing is carried out by a kexin-like convertase.
View details for DOI 10.1016/j.febslet.2008.08.025
View details for Web of Science ID 000260806700016
View details for PubMedID 18775699