De novo domestication of wild tomato using genome editing

Breeding of crops over millennia for yield and productivity1 has led to reduced genetic diversity. As a result, beneficial traits of wild species, such as disease resistance and stress tolerance, have been lost2. We devised a CRISPR–Cas9 genome engineering strategy to combine agronomically desirable traits with useful traits present in wild lines. We report that editing of six loci that are important for yield and productivity in present-day tomato crop lines enabled de novo domestication of wild Solanum pimpinellifolium. Engineered S. pimpinellifolium morphology was altered, together with the size, number and nutritional value of the fruits. Compared with the wild parent, our engineered lines have a threefold increase in fruit size and a tenfold increase in fruit number. Notably, fruit lycopene accumulation is improved by 500% compared with the widely cultivated S. lycopersicum. Our results pave the way for molecular breeding programs to exploit the genetic diversity present in wild plants

Rationale, study design, and analysis plan of the Alveolar Recruitment for ARDS Trial (ART): Study protocol for a randomized controlled trial

Background: Acute respiratory distress syndrome (ARDS) is associated with high in-hospital mortality. Alveolar recruitment followed by ventilation at optimal titrated PEEP may reduce ventilator-induced lung injury and improve oxygenation in patients with ARDS, but the effects on mortality and other clinical outcomes remain unknown. This article reports the rationale, study design, and analysis plan of the Alveolar Recruitment for ARDS Trial (ART). Methods/Design: ART is a pragmatic, multicenter, randomized (concealed), controlled trial, which aims to determine if maximum stepwise alveolar recruitment associated with PEEP titration is able to increase 28-day survival in patients with ARDS compared to conventional treatment (ARDSNet strategy). We will enroll adult patients with ARDS of less than 72 h duration. The intervention group will receive an alveolar recruitment maneuver, with stepwise increases of PEEP achieving 45 cmH(2)O and peak pressure of 60 cmH2O, followed by ventilation with optimal PEEP titrated according to the static compliance of the respiratory system. In the control group, mechanical ventilation will follow a conventional protocol (ARDSNet). In both groups, we will use controlled volume mode with low tidal volumes (4 to 6 mL/kg of predicted body weight) and targeting plateau pressure <= 30 cmH2O. The primary outcome is 28-day survival, and the secondary outcomes are: length of ICU stay; length of hospital stay; pneumothorax requiring chest tube during first 7 days; barotrauma during first 7 days; mechanical ventilation-free days from days 1 to 28; ICU, in-hospital, and 6-month survival. ART is an event-guided trial planned to last until 520 events (deaths within 28 days) are observed. These events allow detection of a hazard ratio of 0.75, with 90% power and two-tailed type I error of 5%. All analysis will follow the intention-to-treat principle. Discussion: If the ART strategy with maximum recruitment and PEEP titration improves 28-day survival, this will represent a notable advance to the care of ARDS patients. Conversely, if the ART strategy is similar or inferior to the current evidence-based strategy (ARDSNet), this should also change current practice as many institutions routinely employ recruitment maneuvers and set PEEP levels according to some titration method.Hospital do Coracao (HCor) as part of the Program 'Hospitais de Excelencia a Servico do SUS (PROADI-SUS)'Brazilian Ministry of Healt

Dynamics of the tree component of a semi-deciduous seasonal forest in advanced successional stage

The increasing land demand for agriculture and urban use contribute for environment degradation. Semi-deciduous seasonal forests (FES), occurring in areas of great population density and relevant economic interest on soil use and occupation remain in marginal areas, especially due to law enforcement (legal reservation and permanent preservation areas). Such lack of care about forest stands and, mostly, about FES explains its fragmented and impoverished florist composition. This study evaluated the conservation status of a forest community, considering the variation in floristic composition, successional group of component species, importance, dominance abundance and frequency of each species; diameter and vertical distribution over a period of five years. The initial hypothesis is that forest fragment isolation would lead to changes in dynamic parameters and in forest composition in time. However, no significant changes were observed in the study area, denoting forest fragment stability. Forest composition did not have marked changes between 2007 and 2012. However, the area presents atypical dominance of some species and such dominance increased during the study period, as shown by the increase in the number of low density occurring species. Forest fragmentation, presently, seems to have had no effect on community dynamic processes. It is unknown if the peculiar species composition and their high dominances in this fragment is the result of fragmentation process, or an interaction between fragmentation and preservation, or if it is a fruit of fragment maturity and preservation. A small decrease in basal area was observed along the five years, resulting from a predominance of mortality over recruitment. However, most species observed basal area increase. The fragment is composed, mostly, by Micrandra elata. This species had such an influence that affected diameter distribution, space distribution, and abundance in the Forest community studied.Fundação de Amparo a Pesquisa do Estado de Minas GeraisMestre em Biologia VegetalA crescente demanda de terras para a agricultura e habitação humana contribui para a degradação ambiental. As florestas estacionais semideciduais (FES), por sua ocorrência em áreas com grande densidade demográfica e relevante interesse econômico no uso e ocupação do solo, são geralmente alocadas em áreas marginais, por força coercitiva da lei (áreas de reserva legal e áreas de preservação permanente). Este descuido em relação às formações florestais e, principalmente, em relação às FES explica a sua situação fragmentada e empobrecida em sua composição florística original. O presente estudo teve como objetivo compreender o estado de conservação da comunidade florestal, levando em consideração a variação entre: a composição florística; o grupo sucessional das espécies que á compõem; a importância, dominância, número e frequência com que as espécies ocorrem; a distribuição diamétrica e vertical com o decorrer de cincos anos. Nossa hipótese inicial seria que o isolamento florestal ocasionaria alguma alteração nos parâmetros dinâmicos e na composição florística com o decorrer dos anos. Entretanto, na área de estudo não houve mudanças significativas, o que denota a estabilidade do fragmento florestal. A composição florística não sofreu alterações marcantes entre os anos de 2007 a 2012. Entretanto, a área em estudo apresenta dominância atípica de algumas espécies e essa dominância aumentou durante o período de estudo, fato este comprovado pelo aumento do número de espécies que ocorrem em baixas densidades. A fragmentação florestal parece não ter interferido, atualmente, nos processos dinâmicos da comunidade. Não se sabe se a composição peculiar em espécies e suas dominâncias elevadas encontrada nessa floresta são resultantes do processo de fragmentação, ou uma interação entre fragmentação e preservação, ou se são fruto da condição madura e preservada da área em estudo. Houve pequeno decremento em área basal no período de cincos anos, resultante do predomínio da mortalidade sobre o recrutamento. Entretanto, as principais espécies obtiveram ganhos em área basal. O fragmento florestal é composto, principalmente, por Micrandra elata. Esta espécie teve expressão o suficiente para influenciar na distribuição diamétrica, na distribuição espacial e na abundância de indivíduos na comunidade florestal estudada

Criação de um novo sistema modelo para genética em Capsicum spp

Capsicum is a genus appreciated for its pungency, which favored the interaction with man and thus domestication. However, through crosses, pungency was removed in modern cultivars and fruit size and productivity were increased, the result of which is what we know as bell peppers. In Capsicum there are gaps in knowledge about phenomena related to hybridization such as heterosis, used to obtain highly productive varieties. This motivated us to perform intra and interspecific crosses with commercial cultivars of C. annuum and C. chinense to determine the extent of the phenomenon of heterosis. Intraspecific hybridization proved to be efficient in maintaining and even improving productive characteristics, while interspecific hybridization promoted extreme vegetative development to the detriment of the reproductive one. In addition, it was observed that reciprocity, compatibility and germination were dependent on the direction in which the crosses were made and the genotypes involved, as well as the influence of the pollen source on the fruit set, size and biometry of fruits. Capsicum fruits are not climacteric, which positions the genus favourably to create a new model system for genetics and physiology. The search for a productive cultivar, with small size and easy cultural management that can be tailored to laboratory work would represent a valuable first step. With this aim in mind, we scanned a germplasm bank for cultivars, mainly of C. annuum, with small size, fast cycle, prolificity and productivity with the task of representing in a reliable way, but in miniature, the productive and genetic potential of Capsicum found in commercial cultivars. After an initial screening of 14 Capsicum cultivars as candidates for the model plant, we found two cultivars of C. annuum here named 75 and CVO. These two cultivars were precocious in the cycle until anthesis and until the first ripe fruit, with compact size and more than adequate prolificacy. In addition, growth and reproduction were not compromised when grown under conditions of high density and root volume limitation, showing that they are able to grow in small spaces and containers, tofacilitate large-scale phenotyping and thus genetic studies. Thus, we found two cultivars suitable to represent in miniature the genetic potential of C. annuum, to allow and facilitate the advancement of genetic studies, and in addition with characteristics inherent and exclusive to the genus Capsicum such as pungency. This new model could represent a valuable contribution to the genetics of non-climacteric fruit ripening and fruit metabolism. Keywords: Plant model. Chili pepper. Hybridization. Heterosis. Yield. Plant growth.Capsicum é um gênero apreciado por sua pungência, o que favoreceu a interação com o homem e consequentemente a domesticação. No entanto, por meio de cruzamentos, a pungência foi removida em cultivares modernas e o tamanho e a produtividade dos frutos aumentaram, resultando no que conhecemos como pimentões. Em Capsicum existem lacunas no conhecimento sobre fenômenos relacionados à hibridização como a heterose, utilizada para a obtenção de variedades altamente produtivas. Isso nos motivou a realizar cruzamentos intra e interespecíficos com cultivares comerciais de C. annuum e C. chinense para determinar a extensão do fenômeno de heterose. A hibridização intraespecífica mostrou-se eficiente em manter e até melhorar as características produtivas, enquanto a hibridização interespecífica promoveu o desenvolvimento vegetativo extremo em detrimento do reprodutivo. Além disso, observou-se que a reciprocidade, compatibilidade e germinação foram dependentes da direção em que os cruzamentos foram feitos e dos genótipos envolvidos, bem como da influência da fonte de pólen na frutificação, tamanho e biometria dos frutos. Os frutos de Capsicum não são climatéricos, o que posiciona o gênero favoravelmente para criar um novo sistema modelo para genética e fisiologia. A busca por uma cultivar produtiva, de pequeno porte e de fácil manejo cultural, que possa ser adaptada ao trabalho de laboratório, representaria um valioso primeiro passo. Com este objetivo, realizamos a varredura de um banco de germoplasma de cultivares, principalmente de C. annuum, com tamanho pequeno, ciclo rápido, prolificidade e produtividade com a tarefa de representar de forma confiável, mas em miniatura, o potencial produtivo e genético de Capsicum encontrada em cultivares comerciais. Após uma triagem inicial de 14 cultivares de Capsicum como candidatas à planta modelo, encontramos duas cultivares de C. annuum aqui denominadas 75 e CVO. Essas duas cultivares foram precoces no ciclo até a antese e até o primeiro fruto maduro, com tamanho compacto e prolificidade mais do que adequada. Alémdisso, o crescimento e a reprodução não foram comprometidos quando cultivados em condições de alta densidade e limitação do volume radicular, mostrando que são capazes de crescer em pequenos espaços e recipientes, facilitando a fenotipagem em larga escala e, consequentemente, os estudos genéticos. Assim, encontramos duas cultivares adequadas para representar em miniatura o potencial genético de C. annuum, para permitir e facilitar o avanço dos estudos genéticos, além de possuir características inerentes e exclusivas ao gênero Capsicum como a pungência. Este novo modelo pode representar uma contribuição valiosa para a genética do amadurecimento e metabolismo de frutos não- climatéricos. Palavras-chave: Planta modelo. Pimenta. Hibridização. Heterose. Produtividade. Crescimento de plantas.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

De novo domestication of wild tomato using genome editing

Breeding of crops over millennia for yield and productivity1 has led to reduced genetic diversity. As a result, beneficial traits of wild species, such as disease resistance and stress tolerance, have been lost2. We devised a CRISPR–Cas9 genome engineering strategy to combine agronomically desirable traits with useful traits present in wild lines. We report that editing of six loci that are important for yield and productivity in present-day tomato crop lines enabled de novo domestication of wild Solanum pimpinellifolium. Engineered S. pimpinellifolium morphology was altered, together with the size, number and nutritional value of the fruits. Compared with the wild parent, our engineered lines have a threefold increase in fruit size and a tenfold increase in fruit number. Notably, fruit lycopene accumulation is improved by 500% compared with the widely cultivated S. lycopersicum. Our results pave the way for molecular breeding programs to exploit the genetic diversity present in wild plants

Rationale, study design, and analysis plan of the Alveolar Recruitment for ARDS Trial (ART): Study protocol for a randomized controlled trial

Background: Acute respiratory distress syndrome (ARDS) is associated with high in-hospital mortality. Alveolar recruitment followed by ventilation at optimal titrated PEEP may reduce ventilator-induced lung injury and improve oxygenation in patients with ARDS, but the effects on mortality and other clinical outcomes remain unknown. This article reports the rationale, study design, and analysis plan of the Alveolar Recruitment for ARDS Trial (ART). Methods/Design: ART is a pragmatic, multicenter, randomized (concealed), controlled trial, which aims to determine if maximum stepwise alveolar recruitment associated with PEEP titration is able to increase 28-day survival in patients with ARDS compared to conventional treatment (ARDSNet strategy). We will enroll adult patients with ARDS of less than 72 h duration. The intervention group will receive an alveolar recruitment maneuver, with stepwise increases of PEEP achieving 45 cmH(2)O and peak pressure of 60 cmH2O, followed by ventilation with optimal PEEP titrated according to the static compliance of the respiratory system. In the control group, mechanical ventilation will follow a conventional protocol (ARDSNet). In both groups, we will use controlled volume mode with low tidal volumes (4 to 6 mL/kg of predicted body weight) and targeting plateau pressure <= 30 cmH2O. The primary outcome is 28-day survival, and the secondary outcomes are: length of ICU stay; length of hospital stay; pneumothorax requiring chest tube during first 7 days; barotrauma during first 7 days; mechanical ventilation-free days from days 1 to 28; ICU, in-hospital, and 6-month survival. ART is an event-guided trial planned to last until 520 events (deaths within 28 days) are observed. These events allow detection of a hazard ratio of 0.75, with 90% power and two-tailed type I error of 5%. All analysis will follow the intention-to-treat principle. Discussion: If the ART strategy with maximum recruitment and PEEP titration improves 28-day survival, this will represent a notable advance to the care of ARDS patients. Conversely, if the ART strategy is similar or inferior to the current evidence-based strategy (ARDSNet), this should also change current practice as many institutions routinely employ recruitment maneuvers and set PEEP levels according to some titration method.13Hospital do Coracao (HCor) as part of the Program 'Hospitais de Excelencia a Servico do SUS (PROADI-SUS)'Brazilian Ministry of Healt