GAS EXCHANGE IN YOUNG PLANTS OF Tabebuia aurea(Bignoniaceae Juss.) SUBJECTED TO FLOODING STRESS1

Abstract

-The Paratudo (Tabebuia aurea) is a species occurring in the Pantanal of Miranda, Mato Grosso do Sul, Brazil, an area characterized by seasonal flooding. To evaluate the tolerance of this plant to flooding, plants aged four months were grown in flooded soil and in non-flooded soil (control group). Stomatal conductance, transpiration and CO 2 assimilation were measured during the stress (48 days) and recovery (11 days) period, totalling 59 days. The values of stomatal conductance of the control group and stressed plants at the beginning of the flooded were 0.33 mol m . Flooded soil reduced photosynthesis and stomatal conductance, leading to the hypertrophy of the lenticels. These parameters recovered and after this period, and plants exhibited tolerance to flooding stress by reducing their physiological activities.Keywords: CO 2 assimilation; Hydric stress; Hypoxia tolerance. TROCAS GASOSAS EM PLANTAS JOVENS DE Tabebuia aurea (Bignoniaceae Juss.) SUBMETIDAS A ESTRESSE POR ALAGAMENTORESUMO -O paratudo, Tabebuia aurea, é uma espécie de larga ocorrência no Pantanal de Miranda, Mato Grosso do Sul, uma área de inundação sazonal. Para determinar o grau de tolerância da espécie ao alagamento, um grupo de plantas com quatro meses de idade foi mantido em vasos alagados, além do grupo controle, com as taxas de condutância estomática, transpiração e assimilação de CO 2 determinadas durante o período de estresse (48 dias) e de recuperação (11 dias), totalizando 59 dias. Em relação aos valores obtidos, a condutância estomática, no início do alagamento, atingiu 0,33 mol m

Gas Exchanges and Antioxidant Activity in <i>Copaifera langsdorffii</i> Desf. Seedlings after Flooding

“…In addition, changes in the photosynthetic apparatus and protection mechanisms associated with the activity of antioxidant enzymes also stand out [6] [7] [8] [9].…”

Seasonal and Spatial Variation of the Iridoid Specioside in Monodominant Formation of Tabebuia Aurea in the Brazilian Pantanal Wetland / Variação Sazonal E Espacial Do Especiosídeo Iridóide Em Formação Monodominante De Tabebuia Aurea Na Zona Húmida Do Pantanal Brasileiro

“…Under these conditions, plant needs more energy for surviving the flood waters, resulting in a decrease of biosynthesis of secondary metabolites (Irfan et al 2010;Ferner et al 2012). This idea is supported by a recent study, where it was observed that plants of T. aurea subjected to flooding conditions reduce their physiological activities (Oliveira and Gualtieri 2016).…”

Biomass Accumulation in the Endangered Shrub Lindera melissifolia as Affected by Gradients of Light Availability and Soil Flooding

“…For example, stomatal closure is a commonly reported early response to soil flooding (Pezeshki 2001, Herrera et al 2008). This stomatal closure decreases CO 2 diffusion into the leaf (Farquhar and Sharkey 1982), leading to a decline in photosynthesis (Lavinsky et al 2007, Mielke and Schaffer 2011, Pimentel et al 2014, Oliveira and Gualtieri 2016, a decrease in photosynthate production, followed by a decline in biomass accumulation (Sena Gomes and Kozlowski 1980, Mielke et al 2003, Mielke and Schaffer 2010, Branco et al 2017.…”