Influência da alta concentração atmosférica de CO2(↑[CO2]atm) × disponibilidade hídrica nas relações hídricas, trocas gasosas e acúmulo de carboidratos em Coffea arabica L.

Abstract

, plants were divided into two groups and submitted to the following water regimes: daily watering and withholding watering for 7, 10, 14 and 37 days, followed by daily rehydration for 7 days. From day 10 on, significant changes in leaf water potential were observed in plants under water suppression in both treatments, with total recovery after rehydration. The A was higher in plants submitted to ↑[CO 2 ] atm , even under water suppression, compared to the daily watering regime. No change in the leaf carbohydrate content was observed in plants cultivated under ↑[CO 2 ] atm and water restriction when compared to those under ↑[CO 2 ] atm and daily watered treatment. However, plants submitted to 400 ppm CO 2 and water restriction showed a significant decrease in the sugar content, mainly in the leaves. Starch contents did not change in response to CO 2 and water treatments. An increase in the rates of leaf proline was observed at the beginning of water restriction, but decreased throughout the experiment. Our results indicate a mitigating effect of the ↑CO 2 on water deficit through the maintenance of carbohydrate accumulation of coffee plants.

Elevated [CO2] Mitigates Drought Effects and Increases Leaf 5-O-Caffeoylquinic Acid and Caffeine Concentrations During the Early Growth of Coffea Arabica Plants

“…Catuaí Vermelho IAC-144 (3-4month-old) obtained in a coffee nursery and having a similar growth pattern were transplanted into 7-liter pots containing Plantmax Café R (DDL Agroindustria Ltda) as substrate, with one plant per pot. After 20-day of acclimation in a greenhouse, plants were transferred to open-top chambers (OTC) installed inside a greenhouse at the Department of Physiology and Biochemistry of the Institute of Botany São Paulo, Brazil, for CO 2 treatment acclimation (ambient atmospheric [CO 2 ] -a[CO 2 ] = 400 ppm or elevated atmospheric [CO 2 ] -e[CO 2 ] = 800 ppm), as described by Sanches et al (2017). The gas injection was applied through a compressed CO 2 cylinder attached to the system.…”

“…The instantaneous net CO 2 assimilation rate (A), stomatal conductance (g s ), leaf transpiration rate (E), and intercellular CO 2 partial pressure (Ci) were determined on fully expanded leaves of the third to fourth pair (from the apex and at the opposite side that w was measured) using a portable infrared gas analyzer (IRGA model LC-SD Pro, ADC Bioscentific), under [CO 2 ] of 400 ppm and 800 ppm, according to plant [CO 2 ] condition, and at photosynthetic saturation light (PPFD of 600 µmol photons m −2 s −1 ) (Sanches et al, 2017). The intrinsic water use efficiency (iWUE) was calculated as A/g s .…”

“…Although few studies have involved woody plants, some of them show a promising beneficial effect of e[CO 2 ] when exposed to abiotic stresses (Ramalho et al, 2013;Xu et al, 2015;Sobuj et al, 2018). In Coffea arabica L., an important commodity worldwide, it was recently demonstrated that e[CO 2 ] promoted higher carbon assimilation rate, water use efficiency and biomass under drought conditions when compared to plants exposed to drought and ambient [CO 2 ] in a greenhouse (Sanches et al, 2017). These responses were also related to lower photorespiration rates and higher hydraulic conductance by the increase of aquaporins transcripts, which contributed to a better performance of these plants under water deficit conditions (Avila et al, 2020a,b).…”

Levantamento De Plantas Condimentares Na Feira Municipal De Humaitá - Am

“…No entanto, o conteúdo foliar de nitrogênio (N) foi reduzido, indicando uma necessidade de aumentar a recomendação de adubação dessa espécie no futuro. Em outro experimento, realizado em câmara de topo aberto (OTC), foi demonstrado que a [CO2] de 760 ppm pode mitigar parcialmente os efeitos da seca na fotossíntese e no acúmulo de carboidratos nas folhas do cafeeiro (SANCHES et al 2017). Ainda, utilizando câmaras de crescimento, Ramalho et al (2018) Além do café, em estudos realizados em goiabeira (Psidium guajava L.) em câmaras de topo aberto (OTCs) não foi encontrado aumento de biomassa aérea ou alteração na concentração de açúcares solúveis em folhas das plantas sob 780 ppm de CO2.…”

Massa de sementes e variação diurna das trocas gasosas em Luetzelburgia auriculata (Alemão) Ducke

“…O conhecimento das condições edafoclimáticas favoráveis e limitantes é fundamental para entender a ecologia e adaptação das espécies florestais ao ambiente, sobretudo na recomposição de ecossistemas naturais, seja na introdução ou reintrodução de determinada espécie [10]. Atrelado a isso, fatores genéticos também possuem forte influência na fisiologia das espécies, contudo, o conhecimento dos parâmetros fisiológicos ao longo do dia nas espécies nativas do semiárido brasileiro são pouco estudados em comparação a outras espécies [11,12].…”