ORCID Profile
0000-0003-3288-8553
Current Organisations
Massachusetts Institute of Technology
,
The University of Texas at Austin
Does something not look right? The information on this page has been harvested from data sources that may not be up to date. We continue to work with information providers to improve coverage and quality. To report an issue, use the Feedback Form.
Publisher: Wiley
Date: 28-03-2019
Publisher: Wiley
Date: 19-03-2021
DOI: 10.1111/PPL.13384
Abstract: The calcifuge habit of plants is commonly explained in terms of high soil pH and its effects on nutrient availability, particularly that of phosphorus (P). However, most Proteaceae that occur on nutrient‐impoverished soils in south‐western Australia are calcifuge, despite their ability to produce cluster‐roots, which effectively mobilize soil P and micronutrients. We hypothesize that the mechanism explaining the calcifuge habit in Proteaceae is their sensitivity to P and calcium (Ca), and that soil‐indifferent species are less sensitive to the interaction of these nutrients. In this study, we analyzed growth, gas‐exchange rate, and chlorophyll fluorescence of two soil‐indifferent and four calcifuge Hakea and Banksia (Proteaceae) species from south‐western Australia, across a range of P and Ca concentrations in hydroponic solution. We observed Ca‐enhanced P toxicity in all analyzed species, but to different extents depending on distribution type and genus. Increasing P supply enhanced plant growth, leaf biomass, and photosynthetic rates of soil‐indifferent species in a pattern largely independent of Ca supply. In contrast, positive physiological responses to increasing [P] in calcifuges were either absent or limited to low Ca supply, indicating that calcifuges were far more sensitive to Ca‐enhanced P toxicity. In calcifuge Hakeas , we attributed this to higher leaf [P], and in calcifuge Banksias to lower leaf zinc concentration. These differences help to explain these species' contrasting sensitivity to Ca‐enhanced P toxicity and account for the exclusion of most Proteaceae from calcareous habitats. We surmise that Ca‐enhanced P toxicity is a major factor explaining the calcifuge habit of Proteaceae, and, possibly, other P‐sensitive plants.
Publisher: Wiley
Date: 15-02-2018
DOI: 10.1111/NPH.15043
Abstract: Plants allocate nutrients to specific leaf cell types, with commelinoid monocots preferentially allocating phosphorus (P) to the mesophyll and calcium (Ca) to the epidermis, whereas the opposite is thought to occur in eudicots. However, Proteaceae from severely P-impoverished habitats present the same P-allocation pattern as monocots. This raises the question of whether preferential P allocation to mesophyll cells is a phylogenetically conserved trait, exclusive to commelinoid monocots and a few Proteaceae, or a trait that has evolved multiple times to allow plants to cope with very low soil P availability. We analysed the P-allocation patterns of 16 species from 10 genera, eight families and six orders within three major clades of eudicots across different P-impoverished environments in Australia and Brazil, using elemental X-ray mapping to quantitatively determine leaf cell-specific nutrient concentrations. Many of the analysed species showed P-allocation patterns that differed substantially from that expected for eudicots. Instead, P-allocation patterns were strongly associated with the P availability in the natural habitat of the species, suggesting a convergent evolution of P-allocation patterns at the cellular level, with P limitation as selective pressure and without a consistent P-allocation pattern within eudicots. Here, we show that most eudicots from severely P-impoverished environments preferentially allocated P to their mesophyll. We surmise that this preferential P allocation to photosynthetically active cells might contribute to the very high photosynthetic P-use efficiency of species adapted to P-impoverished habitats.
Publisher: Springer Science and Business Media LLC
Date: 24-04-2019
Publisher: Magnolia Press
Date: 16-09-2015
DOI: 10.11646/PHYTOTAXA.226.3.8
Abstract: Philcoxia rhizomatosa, a new species of the carnivorous genus Philcoxia from tribe Gratioleae (Plantaginaceae), is here described and illustrated. The species has larger leaves than the other members of the genus, presents a conspicuous and branched rhizome and is the only one with entirely glabrous inflorescence, pedicel and calyx. This taxon is possibly endemic to a sandy outcrop in the transition vegetation between the Cerrado and the Caatinga in the municipality of Botumirim, Minas Gerais, Brazil. Preliminary tests for carnivory were performed and showed the presence of nematodes and activity of phosphatase on leaf surfaces, suggesting that P. rhizomatosa is a carnivorous plant.
Publisher: Springer Science and Business Media LLC
Date: 30-09-2021
DOI: 10.1038/S41597-021-01006-6
Abstract: We introduce the AusTraits database - a compilation of values of plant traits for taxa in the Australian flora (hereafter AusTraits). AusTraits synthesises data on 448 traits across 28,640 taxa from field c aigns, published literature, taxonomic monographs, and in idual taxon descriptions. Traits vary in scope from physiological measures of performance (e.g. photosynthetic gas exchange, water-use efficiency) to morphological attributes (e.g. leaf area, seed mass, plant height) which link to aspects of ecological variation. AusTraits contains curated and harmonised in idual- and species-level measurements coupled to, where available, contextual information on site properties and experimental conditions. This article provides information on version 3.0.2 of AusTraits which contains data for 997,808 trait-by-taxon combinations. We envision AusTraits as an ongoing collaborative initiative for easily archiving and sharing trait data, which also provides a template for other national or regional initiatives globally to fill persistent gaps in trait knowledge.
Publisher: Oxford University Press (OUP)
Date: 09-04-2019
DOI: 10.1093/JXB/ERZ156
Abstract: Over 650 Proteaceae occur in south-western Australia, contributing to the region’s exceptionally high bio ersity. Most Proteaceae occur exclusively on severely nutrient-impoverished, acidic soils (calcifuge), whilst only few also occur on young, calcareous soils (soil-indifferent), higher in calcium (Ca) and phosphorus (P). The calcifuge habit of Proteaceae is explained by Ca-enhanced P toxicity, putatively linked to the leaf cell-specific allocation of Ca and P. Separation of these elements is essential to avoid the deleterious precipitation of Ca-phosphate. We used quantitative X-ray microanalysis to determine leaf cell-specific nutrient concentrations of two calcifuge and two soil-indifferent Proteaceae grown in hydroponics at a range of Ca and P concentrations. Calcium enhanced the preferential allocation of P to palisade mesophyll (PM) cells under high P conditions, without a significant change in whole leaf [P]. Calcifuges showed a greater PM [P] compared with soil-indifferent species, corresponding to their greater sensitivity. This study advances our mechanistic understanding of Ca-enhanced P toxicity, supporting the proposed model, and demonstrating its role in the calcifuge distribution of Proteaceae. This furthers our understanding of nutrient interactions at the cellular level and highlights its importance to plant functioning.
Publisher: Wiley
Date: 29-09-2019
DOI: 10.1111/NPH.15447
Abstract: Many Proteaceae are highly phosphorus (P)-sensitive and occur exclusively on old nutrient-impoverished acidic soils (calcifuge), whilst a few also occur on young calcareous soils (soil-indifferent) that are higher in available calcium (Ca) and P. Calcium increases the severity of P-toxicity symptoms, but its underlying mechanisms are unknown. We propose that Ca-enhanced P toxicity explains the calcifuge habit of most Proteaceae. Four calcifuge and four soil-indifferent Proteaceae from South-Western Australia were grown in hydroponics, at a range of P and Ca concentrations. Calcium increased the severity of P-toxicity symptoms in all species. Calcifuge Proteaceae were more sensitive to Ca-enhanced P toxicity than soil-indifferent ones. Calcifuges shared these traits: low leaf zinc concentration ([Zn]), low Zn allocation to leaves, low leaf [Zn]:[P], low root : shoot ratio, and high seed P content, compared with soil-indifferent species. This is the first demonstration of Ca-enhanced P toxicity across multiple species. Calcium-enhanced P toxicity provides an explanation for the calcifuge habit of most Proteaceae and is critical for the management of this iconic Australian family. This study represents a major advance towards an understanding of the physiological mechanisms of P toxicity and its role in the distribution of Proteaceae.
Publisher: Wiley
Date: 16-11-2022
DOI: 10.1111/GCB.16501
Abstract: “Least‐cost theory” posits that C 3 plants should balance rates of photosynthetic water loss and carboxylation in relation to the relative acquisition and maintenance costs of resources required for these activities. Here we investigated the dependency of photosynthetic traits on climate and soil properties using a new Australia‐wide trait dataset spanning 528 species from 67 sites. We tested the hypotheses that plants on relatively cold or dry sites, or on relatively more fertile sites, would typically operate at greater CO 2 drawdown (lower ratio of leaf internal to ambient CO 2 , C i : C a ) during light‐saturated photosynthesis, and at higher leaf N per area (N area ) and higher carboxylation capacity ( V cmax 25 ) for a given rate of stomatal conductance to water vapour, g sw . These results would be indicative of plants having relatively higher water costs than nutrient costs. In general, our hypotheses were supported. Soil total phosphorus (P) concentration and (more weakly) soil pH exerted positive effects on the N area – g sw and V cmax 25 – g sw slopes, and negative effects on C i : C a . The P effect strengthened when the effect of climate was removed via partial regression. We observed similar trends with increasing soil cation exchange capacity and clay content, which affect soil nutrient availability, and found that soil properties explained similar amounts of variation in the focal traits as climate did. Although climate typically explained more trait variation than soil did, together they explained up to 52% of variation in the slope relationships and soil properties explained up to 30% of the variation in in idual traits. Soils influenced photosynthetic traits as well as their coordination. In particular, the influence of soil P likely reflects the Australia's geologically ancient low‐relief landscapes with highly leached soils. Least‐cost theory provides a valuable framework for understanding trade‐offs between resource costs and use in plants, including limiting soil nutrients.
Publisher: Proceedings of the National Academy of Sciences
Date: 09-01-2012
Abstract: The recently described genus Philcoxia comprises three species restricted to well lit and low-nutrient soils in the Brazilian Cerrado. The morphological and habitat similarities of Philcoxia to those of some carnivorous plants, along with recent observations of nematodes over its subterranean leaves, prompted the suggestion that the genus is carnivorous. Here we report compelling evidence of carnivory in Philcoxia of the Plantaginaceae, a family in which no carnivorous members are otherwise known. We also document both a unique capturing strategy for carnivorous plants and a case of a plant that traps and digests nematodes with underground adhesive leaves. Our findings illustrate how much can still be discovered about the origin, distribution, and frequency of the carnivorous syndrome in angiosperms and, more generally, about the ersity 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 bio ersity hotspots.
Publisher: University of Chicago Press
Date: 2020
DOI: 10.1086/706190
Publisher: Springer Science and Business Media LLC
Date: 09-09-2020
Location: United States of America
No related grants have been discovered for Caio Guilherme Pereira.