Present and Past Research

Identifying the role of structural genetic variation in plant-environment interactions

Understanding the mechanisms that underlie plant-environment interaction is a longstanding goal in biological research. In attempting to achieve this goal, plant scientists have significantly advanced our knowledge in fields that range from ecology and plant physiology to molecular biology and genomics. Curiously, in spite of the efforts to answer the same questions, there seems to be divorce between eco-physiological research and genomic analyses. While this gap is getting narrower, there is still a long way to go until these disciplines are consolidated in a significant fashion. My postdoctoral work aims to tackle this problem, integrating data on the structural genetic variation of Brachypodium with their physiological responses to water and nutrient limitation in order to uncover the role of genome composition in plant functioning. To do so, I am completing and characterizing the pan-genome of two species with contrasting life histories (annual vs. perennial) to determine how differentially present genes may affect plant responses to environmental challenges.

Physiological and molecular aspects of phosphorus efficiency in Proteaceae and beyond

During my PhD, I analysed several aspects of highly-efficient use of phosphorus (P) in Proteaceae and beyond, with a special focus on the implications of P-efficiency mechanisms on species distribution. In the first experiments, my goal was to analyse the extremely high P-use efficiency of Proteaceae from P-impoverished habitats across the Jurien Bay chronosequence in south-western Australia and its link with P toxicity. In summary, I found that high sensitivity to calcium (Ca)-enhanced P toxicity is one of the leading factors explaining the distribution of calcifuge Proteaceae, and that this is due to the cell-specific interactions of P and Ca and their effects on the zinc (Zn) metabolism. After that, I explored the P-allocation pattern of Proteaceae, a trait that partially explains these species’ exceptionally high PPUE and a defining factor explaining the phenomenon of Ca-enhanced P toxicity. I performed the first survey to determine whether the allocation of P to the mesophyll has evolved exclusively in Proteaceae or, alternatively, if it evolved multiple times in other species that naturally occur in severely P-impoverished environments. In summary, my thesis work provides insight into strategies allowing efficient use of P in Proteaceae and beyond, particularly those associated with nutrient allocation patterns at the leaf-tissue level. This is the first time patterns of P allocation are considered in terms of P use efficiency in plants, and the results suggest that these are relevant traits in explaining the functioning of species and their natural distribution.

Underground leaves of Philcoxia trap and digest nematodes

The recently described genus Philcoxia comprises three species restricted to well lit and nutrient-poor soils in the Brazilian Cerrado. The morphological and habitat similarities of Philcoxia to those of known carnivorous plants, along with observations of nematodes over its subterranean leaves, prompted the suggestion that the genus is carnivorous. In this study we reported compelling evidence of carnivory in Philcoxia of the Plantaginaceae, a family in which no carnivorous members are otherwise known. We also documented both a unique capturing strategy for carnivorous plants and a case of a species that traps and digests nematodes with underground adhesive leaves. Our findings illustrate how much can still be discovered regarding the origin, distribution, and frequency of the carnivorous syndrome in angiosperms and, more generally, about the diversity of nutrient-acquisition mechanisms that have evolved in plants growing in severely nutrient-impoverished environments such as the Brazilian Cerrado, one of the world's 34 biodiversity hotspots (Myers et al., 2000).