What is quantitative plant biology?

Quantitative plant biology is an interdisciplinary field that builds on a long history of biomathematics and biophysics. Today, thanks to high spatiotemporal resolution tools and computational modelling, it sets a new standard in plant science. Acquired data, whether molecular, geometric or mechanical, are quantified, statistically assessed and integrated at multiple scales and across fields. They feed testable predictions that, in turn, guide further experimental tests. Quantitative features such as variability, noise, robustness, delays or feedback loops are included to account for the inner dynamics of plants and their interactions with the environment. Here, we present the main features of this ongoing revolution, through new questions around signalling networks, tissue topology, shape plasticity, biomechanics, bioenergetics, ecology and engineering. In the end, quantitative plant biology allows us to question and better understand our interactions with plants. In turn, this field opens the door to transdisciplinary projects with the society, notably through citizen science.Peer reviewe

Risk profiles and one-year outcomes of patients with newly diagnosed atrial fibrillation in India: Insights from the GARFIELD-AF Registry.

BACKGROUND: The Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF) is an ongoing prospective noninterventional registry, which is providing important information on the baseline characteristics, treatment patterns, and 1-year outcomes in patients with newly diagnosed non-valvular atrial fibrillation (NVAF). This report describes data from Indian patients recruited in this registry. METHODS AND RESULTS: A total of 52,014 patients with newly diagnosed AF were enrolled globally; of these, 1388 patients were recruited from 26 sites within India (2012-2016). In India, the mean age was 65.8 years at diagnosis of NVAF. Hypertension was the most prevalent risk factor for AF, present in 68.5% of patients from India and in 76.3% of patients globally (P < 0.001). Diabetes and coronary artery disease (CAD) were prevalent in 36.2% and 28.1% of patients as compared with global prevalence of 22.2% and 21.6%, respectively (P < 0.001 for both). Antiplatelet therapy was the most common antithrombotic treatment in India. With increasing stroke risk, however, patients were more likely to receive oral anticoagulant therapy [mainly vitamin K antagonist (VKA)], but average international normalized ratio (INR) was lower among Indian patients [median INR value 1.6 (interquartile range {IQR}: 1.3-2.3) versus 2.3 (IQR 1.8-2.8) (P < 0.001)]. Compared with other countries, patients from India had markedly higher rates of all-cause mortality [7.68 per 100 person-years (95% confidence interval 6.32-9.35) vs 4.34 (4.16-4.53), P < 0.0001], while rates of stroke/systemic embolism and major bleeding were lower after 1 year of follow-up. CONCLUSION: Compared to previously published registries from India, the GARFIELD-AF registry describes clinical profiles and outcomes in Indian patients with AF of a different etiology. The registry data show that compared to the rest of the world, Indian AF patients are younger in age and have more diabetes and CAD. Patients with a higher stroke risk are more likely to receive anticoagulation therapy with VKA but are underdosed compared with the global average in the GARFIELD-AF. CLINICAL TRIAL REGISTRATION-URL: http://www.clinicaltrials.gov. Unique identifier: NCT01090362

Modelling wood formation and structure: power and limits of a morphogenetic gradient in controlling xylem cell proliferation and growth

The emergence of the characteristic tree-ring pattern during xylogenesis is commonly thought to be controlled by a gradient of morphogen (auxin, TDIF peptide...). We show that this hypothesis accounts for several developmental aspects of wood formation, but not for the final anatomical structure

Combining advanced photoelectron spectroscopy approaches to analyse deeply buried GaP(As)/Si(1 0 0) interfaces: Interfacial chemical states and complete band energy diagrams

The epitaxial growth of the polar GaP(1 0 0) on the nonpolar Si(1 0 0) substrate suffers from inevitable defects at the antiphase domain boundaries (APDs), resulting from mono-atomic steps on the Si(1 0 0) surface. Stabilization of Si(1 0 0) substrate surfaces with As is a promising technological step enabling the preparation of Si substrates with double atomic steps and reduced density of the APDs. In this paper, 4–50-nm-thick GaP epitaxial films were grown on As-terminated Si(1 0 0) substrates with different types of doping, miscuts, and As-surface termination by metalorganic vapor phase epitaxy (MOVPE). The GaP(As)/Si(1 0 0) heterostructures were investigated by X-ray photoelectron spectroscopy (XPS) combined with gas cluster ion beam (GCIB) sputtering and by hard X-ray photoelectron spectroscopy (HAXPES). We found residuals of As atoms in the GaP lattice (∼0.2–0.3 at.%) and a localization of As atoms at the GaP(As)/Si(1 0 0) interface (∼1 at.%). Deconvolution of core level peaks revealed interface core level shifts. In As core levels, chemical shifts between 0.5 and 0.8 eV were measured and identified by angle-resolved XPS measurements. Similar valence band offset (VBO) values of 0.6 eV were obtained, regardless of the doping type of Si substrate, Si substrate miscut or type of As-terminated Si substrate surface. The band alignment diagram of the GaP(As)/Si(1 0 0) heterostructure was deduced

What is quantitative plant biology?

Quantitative plant biology is an interdisciplinary field that builds on a long history of biomathematics and biophysics. Today, thanks to high spatiotemporal resolution tools and computational modelling, it sets a new standard in plant science. Acquired data, whether molecular, geometric or mechanical, are quantified, statistically assessed and integrated at multiple scales and across fields. They feed testable predictions that, in turn, guide further experimental tests. Quantitative features such as variability, noise, robustness, delays or feedback loops are included to account for the inner dynamics of plants and their interactions with the environment. Here, we present the main features of this ongoing revolution, through new questions around signalling networks, tissue topology, shape plasticity, biomechanics, bioenergetics, ecology and engineering. In the end, quantitative plant biology allows us to question and better understand our interactions with plants. In turn, this field opens the door to transdisciplinary projects with the society, notably through citizen science

Influência do estado nutricional de minicepas no enraizamento de miniestacas de eucalipto

O enraizamento adventício de estacas é influenciado por fatores intrínsecos e extrínsecos do material vegetal. O conhecimento sobre o modo de ação desses fatores sobre o enraizamento é fundamental para o sucesso da produção de mudas por miniestaquia. Entre os fatores envolvidos no enraizamento, pode-se destacar a nutrição mineral, pois existe significativa relação entre ela e o enraizamento. No entanto, a importância de vários nutrientes nesse processo ainda não está totalmente esclarecida. Diante do exposto, o objetivo deste trabalho foi avaliar o grau de associação linear entre o estado nutricional das minicepas com o enraizamento de miniestacas de eucalipto. Foram utilizados dados da empresa CENIBRA, entre os quais se analisaram os de enraizamento de miniestacas e dos teores de nutrientes revelados por análises químicas dos tecidos foliares das minicepas. Os dados usados foram originados de minijardim clonal cultivado em leito de areia, com fertirrigação por gotejamento. Com esses dados, foram realizadas análises para avaliar a existência de correlação linear entre as concentrações de macro e micronutrientes nas minicepas e a taxa de enraizamento das miniestacas. Os resultados indicaram que a nutrição mineral desempenha papel importante no enraizamento adventício das miniestacas produzidas pelas minicepas, gerando respostas diferenciadas de acordo com o nutriente considerado. Os resultados evienciaram que a solução nutritiva aplicada no minijardim clonal deve ser específica para cada clone.The adventitious rooting of cuttings is influenced by intrinsic and extrinsic factors of the plant material. The knowledge about the way of the action of these factors upon rooting is essential for the success of the seedling production by minicuttings. Among the factors involved in rooting the mineral nutrition can be emphasized because there is a significant relation between it and rooting, but the importance of various nutrients in this process has not been completely explained yet. Thus, the objective of this work was to evaluate the linear association degree between the nutritional status of ministumps with the rooting of eucalyptus minicuttings. Data from the CENIBRA enterprise were used, and those of rooting of minicuttings and the nutrient contents found in chemical analyses of leaf tissues of the ministumps were analyzed. The data used were from a clonal minigarden grown in sand beds, with fertirrigation by dripping. With these data, analyses were performed to evaluate the existence of a linear correlation among the concentrations of macro and micronutrients in the ministumps and the rooting rate of the minicuttings. The results indicate that the mineral nutrition plays an important role on the adventitious rooting of the minicuttings produced by the ministumps, generating different responses according to the nutrient considered. The results of this study indicate that the nutritive solution used in the clonal minigarden must be specific for each clone

Rooting of healthy and CVC-affected 'Valência' sweet orange stem cuttings, through the use of plant regulators

Citrus variegated chlorosis (CVC) is a disease caused by Xylella fastidiosa. Using different concentrations of plant regulators, such as auxins (indole-3-butyric acid) and gibberellic acid biosynthesis-inhibitor (paclobutrazol), physiological rooting capacity of healthy and CVC-affected stem cuttings were evaluated in order to investigate the importance of plant hormone imbalance and xylem occlusion in plants with CVC. The percentages of dead, alive and rooted cuttings, cuttings with callus and mean number of roots per cuttings did not show statistical differences in response to the distinct concentrations of synthetic plant regulators. There were differences only between healthy and CVC-affected cuttings. This showed the importance of xylem occlusion and diffusive disturbances in diseased plants, in relation to root initiation capacity and hormonal translocation in the plant tissue.<br>Clorose variegada dos citros (CVC) é uma doença causada por Xylella fastidiosa, podendo determinar oclusão do xilema e desbalanço hormonal, o que por fim está relacionado ao processo de iniciação radicial em estacas. Usando diferentes concentrações de fitorreguladores, como auxinas (ácido 3-indol butírico) e inibidores da biossíntese de ácido giberélico (paclobutrazol), que são promotores do enraizamento de estacas, verificou-se a capacidade fisiológica de enraizamento de estacas sadias e com CVC, a fim de investigar a importância do desbalanço hormonal e oclusão do xilema em plantas doentes. As porcentagens de estacas mortas, vivas, enraizadas e com calo e o número médio de raízes por estaca não mostraram diferenças estatísticas em resposta às diferentes concentrações dos reguladores vegetais sintéticos. Houve diferenças apenas entre estacas sadias e doentes. Isto aponta a importância da oclusão do xilema e distúrbios difusivos em plantas doentes, em relação à capacidade de iniciação radicial e à translocação hormonal no tecido vegetal