Papers by Graciela Berrios
Frontiers in Plant Science, 2020
BMC Plant Biology, 2020
Background Filmy-ferns (Hymenophyllaceae) are poikilohydric, homoiochlorophyllous desiccation-tol... more Background Filmy-ferns (Hymenophyllaceae) are poikilohydric, homoiochlorophyllous desiccation-tolerant (DT) epiphytes. They can colonize lower and upper canopy environments of humid forest. Filmy-ferns desiccate rapidly (hours), contrasting with DT angiosperms (days/weeks). It has been proposed that desiccation tolerance in filmy-ferns would be associated mainly with constitutive features rather than induced responses during dehydration. However, we hypothesize that the inter-specific differences in vertical distribution would be associated with different dynamics of gene expression within the dehydration or rehydration phases. A comparative transcriptomic analysis with an artificial neural network was done on Hymenophyllum caudiculatum (restricted to lower canopy) and Hymenophyllum dentatum (reach upper canopy) during a desiccation/rehydration cycle. Results Raw reads were assembled into 69,599 transcripts for H. dentatum and 34,726 transcripts for H. caudiculatum. Few transcripts ...
Background Filmy-ferns (Hymenophyllaceae) are poikilohydric, homoiochlorophyllous desiccation-tol... more Background Filmy-ferns (Hymenophyllaceae) are poikilohydric, homoiochlorophyllous desiccation-tolerant (DT) epiphytes. They can colonize lower and upper canopy environments of humid forest. Filmy-ferns desiccate rapidly (hours), contrasting with DT angiosperms (days/weeks). We hypothesized that desiccation tolerance in filmy-ferns would be associated mainly with constitutive features rather than induced responses during dehydration. Hence, the inter-specific differences in vertical distribution would be associated with different dynamics of gene expression within the dehydration or rehydration phases. A comparative transcriptomic analysis with an artificial neural network was done on Hymenophyllum caudiculatum (restricted to lower canopy) and Hymenophyllum dentatum (reach upper canopy) during a desiccation/rehydration cycle.Results Raw reads were assembled into 69,599 transcripts for H. dentatum and 34,726 transcripts for H. caudiculatum . Few transcripts showed significant changes ...
Polar Biology, 2012
Deschampsia antarctica is the only hair grass that has been able to successfully colonize the Ant... more Deschampsia antarctica is the only hair grass that has been able to successfully colonize the Antarctic continent. However, there is little research on the role of microorganisms associated with the rhizosphere that may participate in its growth and development. The objective of this research was to characterize a psychrotolerant bacterial strain isolated from the rhizosphere of D. antarctica. Biochemical and molecular studies were performed to characterize this bacterium. It was determined that this strain secretes a neutral polysaccharide that presents different compositions at different temperatures (4 and 20 °C). Based on biochemical and phylogenetic analyses, the Antarctic rhizobacterium could be a new species of Pseudomonas. To determine their ability to solubilize different sources of inorganic phosphate, qualitative and quantitative analyses were conducted to determine P released at 4 °C. The Antarctic strain of Pseudomonas sp. was able to solubilize all sources of phosphates, and 34.2 mg P/L was released from rock phosphate. Growth physiological parameters were evaluated for seedlings of D. antarctica inoculated with the rhizobacteria. It was found that the bacterial inoculation promoted plant root development. SEM analysis of the roots showed that the bacterium is mainly located in the root hairs of D. antarctica.
Plant Physiology and Biochemistry, 2019
We evaluated whether phosphorus (P) ameliorates manganese (Mn) excess harmful effects on photosyn... more We evaluated whether phosphorus (P) ameliorates manganese (Mn) excess harmful effects on photosynthetic performance, growth, oxidative stress, and antioxidants in ryegrass. Two perennial ryegrass genotypes, Banquet-II as Mn-resistant and One-50 as Mn-sensitive genotype, were growth under hydroponic conditions subjected to increased P (25, 50, 100, 200 and 400 μM), excess (750 μM) and sufficient Mn (2.4 μM) for 15 days. Growth rate, lipid peroxidation (LP), enzymatic and non-enzymatic antioxidants, photosynthetic parameters, and pigments were determined. Significant reduction of photosynthesis and growth in One-50 was observed under Mn-excess combined with low and adequate P, recovering under greater P-doses. The P concentration of both genotypes was enhanced towards increased P-supply, regardless of Mn treatments. Shoots Mn-concentration remained constant in both genotypes under Mn-excess, independently of P-levels; meanwhile, Banquet-II roots Mn-concentration increased 23% by P-supply. Furthermore, Banquet-II roots showed higher superoxide dismutase (SOD) activity than One-50, which increased towards the highest P dose under sufficient and excess of Mn. A high dose of phosphorus amendment alleviated Mn-toxicity in Mn-sensitive genotype (One-50). Besides, in the Mn-resistant genotype, enhanced plant performance is highlighted, explained by a high Mn-accumulation in roots and increased SOD activity, decreasing Mn translocation to shoots and therefore protecting the photosynthetic apparatus.
ABSTRACTFerns from the Hymenophyllaceae family are one of the main components of the epiphytic sp... more ABSTRACTFerns from the Hymenophyllaceae family are one of the main components of the epiphytic species diversity in the Chilean temperate rain forest. Having membranous fronds of a single layer of cells, they show a poikilohydric strategy most typical from bryophytes. Although Hymenophyllaceae species shows the ability to tolerate desiccation, there are interspecific differences in their water loss kinetic. Counter-intuitively, those species that have rapid desiccation kinetic are able to reach higher host height and tolerate higher light exposure and vapor pressure deficit. Therefore, what are the mechanisms (constitutive and/or induced) responsible of the desiccation tolerance in this fern family? As this primitive fern family is closely related with mosses, it can be hypothesized that desiccation tolerance in this particular group would be associated with constitutive features rather than induced responses during dehydration. However, the inter-specific differences in water loss ...
Plant Physiology and Biochemistry, 2017
We studied physiological traits and Mn transporter genes expression in ryegrass genotypes (One-50... more We studied physiological traits and Mn transporter genes expression in ryegrass genotypes (One-50, Banquet-II, Halo-AR1 and Nui) under increasing Mn (2.4-750 µM) at short-term (8-24 h) in nutrient solution. An increment in Mn concentration occurred early in roots of all genotypes at increased Mn doses relative to control. Banquet-II and Nui roots showed the greatest Mn concentration at the highest Mn supply. Net photosynthesis (Pn) of Banquet-II and Halo-AR1 were not perturbed by Mn doses, whereas One-50 and Nui, decayed strongly at the highest Mn dose, concomitant with reduced total chlorophyll concentration. A high accumulation of Mn in roots together the maintained Pn under increased Mn doses in Banquet-II and Halo-AR1 suggest a higher Mn resistance of these genotypes. Stomatal conductance (gs) of all genotypes did not vary in presence of Mn. In roots of Banquet-II an augment of lipid peroxidation (LP) by Mn excess was observed earlier decreasing afterwards, being attenuated by the augment of the radical scavenging activity (RSA) and total phenols (TP) of this genotype. Mn concentration and LP in tissues of One-50 and Nui genotypes rose together, may be due to its Mn sensitivity. Differential expression of Mn transporter genes were found in the studied genotypes grown under increasing supplies of Mn, being MTP8.1 expressed in shoots and NRAMP2-like in roots. We concluded that Banquet-II showed greater Mn concentration associated to high roots NRAMP2-like gene expression, without changes in photosynthetic performance. Despite, this
Plant Physiology and Biochemistry, 2017
Physiological and biochemical responses to manganese toxicity in ryegrass (Lolium perenne L.) gen... more Physiological and biochemical responses to manganese toxicity in ryegrass (Lolium perenne L.) genotypes
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Papers by Graciela Berrios