Nota sobre la distribució actual i hàbitat de Melaraphe punctata (Gmelin, 1789) (Mollusca, Gastropoda) a Mallorca

Abstract not availabl

Contribution to the knowledge of the flora and fauna of the sea bed of Cala Rafeubetx (SW of Mallorca, Balearic Islands)

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Modeling the effects of light and sucrose on in vitro propagated plants: A multiscale system analysis using artificial intelligence technology

Background: Plant acclimation is a highly complex process, which cannot be fully understood by analysis at any one specific level (i.e. subcellular, cellular or whole plant scale). Various soft-computing techniques, such as neural networks or fuzzy logic, were designed to analyze complex multivariate data sets and might be used to model large such multiscale data sets in plant biology. Methodology and Principal Findings: In this study we assessed the effectiveness of applying neuro-fuzzy logic to modeling the effects of light intensities and sucrose content/concentration in the in vitro culture of kiwifruit on plant acclimation, by modeling multivariate data from 14 parameters at different biological scales of organization. The model provides insights through application of 14 sets of straightforward rules and indicates that plants with lower stomatal aperture areas and higher photoinhibition and photoprotective status score best for acclimation. The model suggests the best condition for obtaining higher quality acclimatized plantlets is the combination of 2.3% sucrose and photonflux of 122-130 μmol m-2 s -1. Conclusions: Our results demonstrate that artificial intelligence models are not only successful in identifying complex nonlinear interactions among variables, by integrating large-scale data sets from different levels of biological organization in a holistic plant systems-biology approach, but can also be used successfully for inferring new results without further experimental work. © 2014 Gago et al.This work was supported by The Regional Government Xunta de Galicia (PGIDIT02BTF30102PR) and Spanish MEC (AGL 2003-05877) to PPG. ML (PR2010-0460) and PPG (PR2010-0357) thank the Spanish Ministry of Education for their financial support during their sabbatical year at Faculty of Science, University of Utrecht, NetherlandsPeer Reviewe

Acclimation of biochemical and diffusive components of photosynthesis in rice, wheat and maize to heat and water deficit:implications for modeling photosynthesis

The impact of the combined effects of heat stress, increased vapor pressure deficit (VPD) and water deficit on the physiology of major crops needs to be better understood to help identify the expected negative consequences of climate change and heat waves on global agricultural productivity. To address this issue, rice, wheat and maize plants were grown under control temperature (CT, 25°C, VPD 1.8 kPa), and a high temperature (HT, 38°C, VPD 3.5 kPa), both under well-watered (WW) and water deficit (WD) conditions. Gas-exchange measurements showed that, in general, WD conditions affected the leaf conductance to CO2, while growth at HT had a more marked effect on the biochemistry of photosynthesis. When combined, HT and WD had an additive effect in limiting photosynthesis. The negative impacts of the imposed treatments on the processes governing leaf gas-exchange were species-dependent. Wheat presented a higher sensitivity while rice and maize showed a higher acclimation potential to increased temperature. Rubisco and PEPC kinetic constants determined in vitro at 25°C and 38°C were used to estimated Vcmax, Jmax and Vpmax in the modeling of C3 and C4 photosynthesis. The results here obtained reiterate the need to use species-specific and temperature-specific values for Rubisco and PEPC kinetic constants for a precise parameterization of the photosynthetic response to changing environmental conditions in different crop species

Physiological and genetic response of olive leaves to water stress and recovery: implications of mesophyll conductance and genetic expression of aquaporins and carbonic anhydrase

8 páginas, 2 figuras, 18 referencias.-- XXVIII International Horticultural Congress on Science and Horticulture for People (IHC2010): International Symposium on CLIMWATER 2010: Horticultural Use of Water in a Changing Climate. Lisboa, Portugal.Drought is considered to be the main environmental factor limiting photo-synthesis (AN) and, consequently, plant growth and yield worldwide. During photosynthesis, the pathway of CO2 from the atmosphere to the site of carboxylation in the chloroplast stroma has two main components: stomatal (gs) and mesophyll (gm) conductances. Both are finite and dynamic, responding to many abiotic factors, therefore reducing CO2 concentration. However, little is known about gm regulation in the short term, where a possible role of aquaporins (AQP) and carbonic anhydrase (CA) has been proposed. Five-year-old olive trees growing in 50 L pots were used to evaluate the acclimation and recovery of AN to drought and subsequent re-watering. Control trees were well-irrigated, while in stressed trees irrigation was withheld for 13 days and then resumed. We made a simultaneous analysis of the genetic expression of two AQP, OePIP1.1 and OePIP2.1, and of CA, on the one hand, and leaf water status, leaf gas exchange and shoot hydraulic conductivity on the other. This is the first time that genetic expression in olive is related to main physiological variables. Two days after withholding irrigation (a.w.i.), the gs and gm values in Stress tress were lower than in Control trees. This limited photosynthesis. Leaf water status decreased from day 4 a.w.i. Midday leaf water potential dropped from -1.2 on the day before withholding irrigation to -6.0 MPa on day 9 a.w.i. CA expression decreased during drought and there was a peak on OePIP1.1 expression on day 4 a.w.i. Leaf water status recovered in ca. 36 h after resuming irrigation. Both gm and AN did not fully recover until 46 days after rewatering. Stomatal conductance, however, did not recover in that period, probably because of an irreversible loss of shoot hydraulic conductivity. Both OePIP1.1 and OePIP2.1 peaked 36 h after rewatering. We found significant correlations between gm and both OePIP2.1 and CA expression.This work was partly supported by grants for projects AGL2005-00220/AGR and AGL-2009-11310.Peer Reviewe

Rubisco catalytic properties optimized for present and future climatic conditions

10 páginas.-- 3 figuras.-- 4 tablas.-- 85 referencias.-- Appendix A. Supplementary dataBecause of its catalytic inefficiencies, Rubisco is the most obvious target for improvement to enhance the photosynthetic capacity of plants. Two hypotheses are tested in the present work: (1) existing Rubiscos have optimal kinetic properties to maximize photosynthetic carbon assimilation in existing higher plants; (2) current knowledge allows proposal of changes to kinetic properties to make Rubiscos more suited to changed conditions in chloroplasts that are likely to occur with climate change. The catalytic mechanism of Rubisco results in higher catalytic rates of carboxylation being associated with decreased affinity for CO2, so that selection for different environments involves a trade-off between these two properties. The simulations performed in this study confirm that the optimality of Rubisco kinetics depends on the species and the environmental conditions. In particular, environmental drivers affecting the CO2 availability for carboxylation (C c) or directly shifting the photosynthetic limitations between Rubisco and RuBP regeneration determine to what extend Rubisco kinetics are optimally suited to maximize CO2 assimilation rate. In general, modeled values for optimal kinetic reflect the predominant environmental conditions currently encountered by the species in the field. Under future climatic conditions, photosynthetic CO2 assimilation will be limited by RuBP-regeneration, especially in the absence of water stress, the largest rise in [CO2] and the lowest increases in temperature. Under these conditions, the model predicts that optimal Rubisco should have high Sc/o and low Kc catThe Spanish Ministry of Science and Innovation (AGL2009-07999 and AGL2009-11310/AGR), the Estonian Ministry of Science and Education (institutional grant IUT-8-3) and the European Commission through the European Regional Fund (the Center of Excellence in Environmental Adaptation). JAP received a pre-doctoral fellowship of Conselleria d’Educació, Cultura i Universitats (Govern de les Illes Balears)Peer reviewe

The Mediterranean evergreen Quercus ilex and the semi-deciduous Cistus albidus differ in their leaf gas exchange regulation and acclimation to repeated drought and re-watering cycles

Plants may exhibit some degree of acclimation after experiencing drought, but physiological adjustments to consecutive cycles of drought and re-watering (recovery) have scarcely been studied. The Mediterranean evergreen holm oak (Q. ilex) and the semi-deciduous rockrose (C. albidus) showed some degree of acclimation after the first of three drought cycles (S1, S2, and S3). For instance, during S2 and S3 both species retained higher relative leaf water contents than during S1, despite reaching similar leaf water potentials. However, both species showed remarkable differences in their photosynthetic acclimation to repeated drought cycles. Both species decreased photosynthesis to a similar extent during the three cycles (20–40% of control values). However, after S1 and S2, photosynthesis recovered only to 80% of control values in holm oak, due to persistently low stomatal (gs) and mesophyll (gm) conductances to CO2. Moreover, leaf intrinsic water use efficiency (WUE) was kept almost constant in this species during the entire experiment. By contrast, photosynthesis of rockrose recovered almost completely after each drought cycle (90–100% of control values), while the WUE was largely and permanently increased (by 50–150%, depending on the day) after S1. This was due to a regulation which consisted in keeping gs low (recovering to 50–60% of control values after re-watering) while maintaining a high gm (even exceeding control values during re-watering). While the mechanisms to achieve such particular regulation of water and CO2 diffusion in leaves are unknown, it clearly represents a unique acclimation feature of this species after a drought cycle, which allows it a much better performance during successive drought events. Thus, differences in the photosynthetic acclimation to repeated drought cycles can have important consequences on the relative fitness of different Mediterranean species or growth forms within the frame of climate change scenarios

Efficiency of water usage in plants

La disponibilidad de agua es el principal factor limitante de la producción agrícola y ganadera en ambientes de clima mediterráneo. Limitación que, ante las previsiones de Cambio Climático Global realizadas por organismo internacionales, serán mucho mayores en los próximos años. En este escenario, la eficiencia en el uso de los recursos hídricos debe ser un aspecto transversal de las políticas públicas que debe, por tanto, ser afrontado desde diversos puntos de vista. En este sentido, uno de los temas claves a considerar es la eficiencia con la que las plantas usan el agua. El objetivo de este trabajo es hacer una revisión de los diferentes aspectos relacionados con este tema, considerando las diferentes escalas a las que se estudia la eficiencia en el uso del agua por las plantas (EUA), desde la hoja hasta el cultivo o el ecosistema. Así, se abordan las dificultades técnicas que existen para medir, de una forma precisa, la EUA de un cultivo o de un ecosistema, la importancia del ambiente y de las prácticas agronómicas como determinantes de la EUA, la diversidad genética inter e intraespecífica, y las implicaciones prácticas de estos factores a la hora de incrementar la EUA.Water availability is the most important limiting factor in plant and animal production under Mediterranean conditions. In a Global Climate Change scenario, this limitation will be even greater in the following years, according to the International Institutions predictions. In this sense, the efficiency of water resources utilization should be a key point of public policies that must be discussed from different points of view. One of these is Plant Water Use Efficiency (WUE). The objective of this paper is to review the different aspects related to WUE, considering the approach levels, from leaf to crop or ecosystem. The technical difficulties to measure accurately WUE at crop or ecosystem level, the environment and agronomical practices importance in WUE determination, the inter and intraspecific plant genetic diversity, as well as the practical implications of each factor to increase WUE are discussed.Los trabajos realizados por el Grup de Biologia de les plantes en condicions mediterrànies sobre eficiencia en el uso del agua forman parte de los proyectos: PRIB-2004-10144, financiado por el Govern de les Illes Balears, e INCO-PERMED (PL 509140), financiado por la Unión Europea

L'evolució de l'ésser humà

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Can a plant physiologist be considered a naturalist?

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