Análise de crescimento e trocas gasosas de plantas de Lonchocarpus sericeus (Poir.) D.C. sob alagamento para uso na recuperação de matas de ciliares

http://dx.doi.org/10.5902/1980509812349In order to select species for using in the restoration of riparian forests on the banks of the Sao FranciscoRiver, in the state of Sergipe, an experiment was conducted to evaluate the growth and gas exchange ofplants Lonchocarpus sericeus (Poir.) D.C., subject to flooding conditions in the nursery. The experimentwas conducted at Forest Nursery, Department of Forest Sciences, Federal University of Sergipe (UFS),the municipality of São Cristóvão, (11 º 01 'S latitude and 37 º 12' longitude W, altitude 20 m) , stateof Sergipe, Brazil, from October 2006 to January 2007 under ambient conditions. We used a completelyrandomized design (CRD), factorial (2x7), two treatments (control - T0, plants at field capacity and flooded- T1) and days after flooding (0, 15, 30, 45, 60, 75 and 90 days). To simulate the condition of flooding,the plants were placed in plastic pots of black color with a volume of 5 L and more substrate. Followingthese pots were attached to pots with a volume of 10 L, which was added water until it reaches a waterdepth of 5 cm above the top of the plants. The control plants kept in pots with a volume of 5 L substratemaintained at field capacity. In non-destructive variables were used four replicates per treatment evaluatedevery fifteen days, where each replicate consists of six plants, totaling 24. Destructive variables used were4 replicates per treatment, determined biweekly from 15 days after flooding, where each replicate consistsof a plant totaling 24 plants. Therefore, 48 plants were used per treatment. The non-destructive variableswere height, diameter and number of leaves. While the destructive variables analyzed were dry weight ofroots, dry weight of shoots and dry weight of root / shoot ratio. In addition, we carried out analysis of gasexchange on a monthly basis and evaluated twelve plants per treatment, with two sampling leaves, fullyexpanded, per plant. The biometric variables were subjected to analysis of variance and subsequently theaverage test (Tukey p <0.05), while the values of gas exchange were taken from the standard deviationsof the mean. Thus, we observe that the flooding caused a reduction in height and dry mass of root / shootratio, from 30 days after treatment application. In addition, flooded plants showed morphological changessuch as hypertrophy of adventitious roots and lenticels, characteristics of species tolerant to flooding. Thenet photosynthetic rate has been reduced by 48.20% compared to control after 60 days. However, despitereductions in growth variables and gas exchange species Lonchocarpus sericeus showed promise in therecovery of riparian vegetation, due to its morphological characteristics of species tolerant to flooding.http://dx.doi.org/10.5902/1980509812349Com o intuito de selecionar espécies para utilização na recuperação de matas ciliares na margem do rio São Francisco localizada no estado de Sergipe foi realizado um experimento com o objetivo de avaliar o crescimento e as trocas gasosas de plantas de Lonchocarpus sericeus (Poir.) D.C., submetidas a alagamento em condição de viveiro. O experimento foi realizado no Viveiro Florestal do Departamento de Ciências Florestais, da Universidade Federal de Sergipe (UFS), no município de São Cristóvão-SE (11º01’ de latitude S e 37º12’ de longitude W, com altitude de 20 m), estado de Sergipe, Brasil, no período de outubro de 2006 a janeiro de 2007 em condição ambiente. Foi utilizado delineamento experimental inteiramente casualizado (DIC), em fatorial (2x7), dois tratamentos (controle – T0, plantas em capacidade de campo e alagadas – T1) e dias após alagamento (0, 15, 30, 45, 60, 75 e 90 dias). Para simular a condição de alagamento, as plantas foram postas em vasos plásticos de cor preta com volume de 5 L e mais substrato. Após, estes vasos foram acoplados a vasos com volume de 10 L, onde foi acrescida a água até atingir lâmina d’água de 5 cm acima do colo das plantas. As plantas do controle permaneceram em vasos com volume de 5 L com substrato mantido na capacidade de campo. Nas variáveis não destrutivas foram utilizadas 4 repetições por tratamento, avaliadas a cada quinze dias, onde cada repetição consta de 6 plantas, totalizando 24. Para as variáveis destrutivas foram utilizadas 4 repetições por tratamento, avaliadas quinzenalmente a partir de 15 dias após o alagamento, onde cada repetição consta de uma planta totalizando 24 plantas. Desta forma foram utilizadas 48 plantas por tratamento. As variáveis não destrutivas foram altura, diâmetro do colo e número de folhas. Enquanto as variáveis destrutivas analisadas foram massa seca da raiz e parte aérea, razão da massa seca da raiz/parte aérea. Além disso, foram realizadas análises de trocas gasosas mensalmente, sendo avaliadas doze plantas por tratamento, com amostragem de duas folhas, completamente expandidas, por planta. As variáveis biométricas foram submetidas à análise de variância e posteriormente ao teste de média (Tukey p<0,05), enquanto dos valores de trocas gasosas foram retirados os desvios padrões das médias. Diante disso, observamos que o alagamento promoveu a redução em altura e na razão massa seca da raiz/parte aérea, a partir dos 30 dias após aplicação do tratamento. Além disso, as plantas alagadas apresentaram modificações morfológicas como raízes adventícias e hipertrofia das lenticelas, características de espécies tolerantes ao alagamento. A taxa fotossintética líquida foi reduzida em 48,20% em relação ao controle aos 60 dias. Todavia, apesar das reduções nas variáveis de crescimento e trocas gasosas, a espécie Lonchocarpus sericeus mostrou-se promissora na recuperação de mata ciliar, por apresentar modificações morfológicas características de espécies tolerantes ao alagamento

CURSO DIÁRIO DAS TROCAS GASOSAS EM PLANTAS DE FEIJÃO-CAUPI SUBMETIDAS A DEFICIÊNCIA HÍDRICA

This work had the objective of checking the echophysiological behavior of cowpea [Vigna unguiculata (L.) Walp.] cv. BRS Xique-xique cultivated under different levels of hydric deficit. The plants were cultivated in vases with capacity for 10L, containing one substratum composed by: 88,45% sand, 3,71% of clay, 7,84 % of silte. The experimental design was entirely randomized with three treatments (TO- reposition of 100% of lost water by evapotranspiration, T1- reposition of 50% and T2- reposition of 25%) and five repelicates. Previously, T1 and T2 suffered a period of stress and were later rehydrated. In the day of the assessment, the plants of T1 had been undergone to stress for three days, while the plants T2 for 5 days. The variables analyzed were: leaf water potential, net photosynthesis, stomatal conductance, transpiration, internal CO2 concentration and foliar temperature. The fewest availability of water caused reductions in the net photosynthesis rates, stomatal conductance and transpiration in T1 and T2 when they were compared to T0. The internal CO2 concentration in T2 was the greater among analyzed treatments. The reposition of 50 % of the lost water hasn´t caused any damage in the net photosynthesis

Resistance Mechanisms of Peltophorum dubium (Sprengel) Taubert Submitted to Flood Conditions

ABSTRACT Peltophorum dubium (Sprengel) Taubert seedlings were submitted to 60 days of flooding, with and without Ca+. During this period, growth, root anatomy and chlorophyll content were analyzed. The relative growth rates (RGR) of roots and shoots were higher in non-flooded plants. The flooded treatments, with and without Ca+, have affected the roots growth but did not affect the shoot and the stem diameter. The anatomy analysis showed thickening of the sclerenchyma in 15 and 60 days in the flooded treatments with and without Ca+, and the vessel diameter was smaller at 45 days. The chlorophyll content differed, however it was not statistically significant. The results indicate that Peltophorum dubium as candidate specie for reforestation in areas subjected to continuous flooding for up to 60 days, since no mortality was observed

Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)

In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field