Diurnal changes in leaflet gas exchange, water status and antioxidant responses in Carapa guianensis plants under water-deficit conditions

2012 ◽  
Vol 35 (1) ◽  
pp. 13-21 ◽  
Author(s):  
Kaliene da Silva Carvalho ◽  
Hugo Alves Pinheiro ◽  
Reginaldo Alves Festucci-Buselli ◽  
Dalton Dias da Silva Júnior ◽  
Gledson Luiz Salgado de Castro ◽  
...  
Keyword(s):  
Gas Exchange ◽  
Water Deficit ◽  
Water Status ◽  
Diurnal Changes ◽  
Antioxidant Responses ◽  
Carapa Guianensis

Effect of irrigation on leaf gas exchange and yield of cashew in northern Australia

1996 ◽  
Vol 36 (7) ◽  
pp. 861 ◽  
Author(s):  
H Schaper ◽  
EK Chacko ◽  
SJ Blaikie
Keyword(s):  
Gas Exchange ◽  
Chlorophyll Content ◽  
Water Deficit ◽  
Leaf Gas Exchange ◽  
Water Status ◽  
Northern Australia ◽  
Wet Season ◽  
Leaf Water Status ◽  
Continuous Irrigation ◽  
Tropical Regions

Gas exchange, leaf water status, soil water use and nut yield of cashew trees were monitored during the reproductive phase in 2 consecutive years (1988 and 1989). Treatment 1 comprised continuous irrigation from the end of the wet season in April until harvest in October; T2, irrigation between flowering (mid June) and harvest; and T3, no irrigation. Irrigation was applied by under-tree sprinkler at 43 mm/week in 1988 and 64 mm/week in 1989. Measurement of leaf gas exchange, chlorophyll content and nut production showed that trees in T2 were as productive as those in T1 (>1.3 kg kernel/tree). In T3, water deficit caused a 4-fold reduction in leaf photosynthesis and reduced leaf chlorophyll content from about 600 to 400 mg/m2 during fruit development. There was no effect on the number of hermaphrodite flowers produced (both ranging from 0 to 15 hermaphrodite flowers/panicle) but the water deficit was associated with a lower kernel yield (1.16 kg kernel/tree). Commercial yields (kg kernel/tree) in irrigated treatments were 20% greater than in the non-irrigated treatment and the kernels from irrigated trees were of a higher grade (kernel recovery >32% in T1 and T2 compared with 27.4% in T3). These results suggest that irrigation of established cashew plantations in the tropical regions of northern Australia can be restricted to the period between flowering and harvest without reducing yield.

Leaf arginine spraying improves leaf gas exchange under water deficit and root antioxidant responses during the recovery period

2021 ◽  
Author(s):  
Neidiquele M. Silveira ◽  
Rafael V. Ribeiro ◽  
Sabrina F.N. de Morais ◽  
Sarah C.R. de Souza ◽  
Simone F. da Silva ◽  
...  
Keyword(s):  
Gas Exchange ◽  
Water Deficit ◽  
Leaf Gas Exchange ◽  
Recovery Period ◽  
Antioxidant Responses

scholarly journals Soybean Plant Metabolism under Water Deficit and Xenobiotic and Antioxidant Agent Application

Biology ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 266
Author(s):  
Julia Renata Schneider ◽  
Mariele Müller ◽  
Vilson Antonio Klein ◽  
Luciana Grazziotin Rossato-Grando ◽  
Rômulo Pillon Barcelos ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Gas Exchange ◽  
Soil Water ◽  
Water Deficit ◽  
Water Availability ◽  
Water Status ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Antioxidant Agent ◽  
Soybean Plants

The aim was to evaluate the interactive effects on biochemistry and physiology of soybean plants exposed to simultaneous xenobiotic and water deficit stresses, and the possible attenuation of plant damage by an antioxidant agent. Soybean plants were submitted to eight different soil water potentials, in two experiments (first experiment: −0.96, −0.38, −0.07, −0.02 MPa, and second experiment: −3.09, −1.38, −0.69, −0.14 MPa), xenobiotic, and antioxidant agent applications. Was observed a reduction in water status, gas exchange, photosynthetic pigments, photosystem II quantum yield, and increased leaf temperature in plants under low water availability. Water deficit also induced oxidative stress by the increased production of reactive oxygen species, cellular and molecular damage, and induction of the antioxidant defense metabolism, reduction of gas exchange, water status, and photosynthetic efficiency. The xenobiotic application also caused changes, with deleterious effects more pronounced in low soil water availability, mainly the reactive oxygen species production, consequently the antioxidant activity, and the oxidative damages. This indicates different responses to the combination of stresses. Antioxidant enzyme activity was reduced by the application of the antioxidant agent. Principal Component Analysis showed a relation with the antioxidant agent and reactive oxygen species, which is probably due to signaling function, and with defense antioxidant system, mainly glutathione, represented by thiols.

scholarly journals Transcriptional insights into sugarcane aquaporin genes under water deficit conditions

2021 ◽  
Author(s):  
DEVENDRA KUMAR
Keyword(s):  
Water Deficit ◽  
Water Status ◽  
Crop Productivity ◽  
Transcript Analysis ◽  
Efficient Utilization ◽  
Sod Activity ◽  
Antioxidant Responses ◽  
New Germplasm

Abstract Water deficit in soil during formative growth stage adversely hinders the crop productivity. Plant develop a key chain of mechanisms to cope these strains. Characterization of genotypes under water deficit will provide the basis for breeding new germplasm for efficient utilization of water and nutrients and adaptation to water stress. To achieve this, two tolerant (Co 98014 and Co 0118) and two sensitive (CoJ 85 and Co 89003) sugarcane genotypes were assessed for antioxidant responses followed by differential expression of three aquaporin genes (ShPIP2-1, ShPIP-5 and ShPIP2-6) under two water deficit conditions. The MDA and H2O2 contents were significantly higher (p<0.05) in sensitive genotypes as compared to tolerant ones, whereas SOD activity was higher (p<0.05) in tolerant than sensitive genotypes. The transcript analysis of AQPs reveals upregulation of ShPIP2;5, whereas down-regulation of ShPIP2;1 and ShPIP2;6 when plants were imposed to water deficit conditions. The findings under study suggested the role of PIP2 AQPs in regulation of plant water status under water deficit conditions.

Water relations and gas exchange in young coconut palm (Cocos nucifera L.) as influenced by water deficit

1997 ◽  
Vol 75 (1) ◽  
pp. 18-27 ◽  
Author(s):  
Anne Repellin ◽  
Serge Braconnier ◽  
Daniel Laffray ◽  
Claude Daniel ◽  
Yasmine Zuily-Fodil
Keyword(s):  
Water Vapor ◽  
Gas Exchange ◽  
Water Deficit ◽  
Drought Resistance ◽  
Water Status ◽  
Cocos Nucifera ◽  
Leaf Water ◽  
Coconut Palm ◽  
Leaf Water Status ◽  
Cocos Nucifera L

Drought is the main climatic limitation to coconut palm (Cocos nucifera L.) production. To identify early screening parameters for drought resistance, physiological responses to water deficit were investigated for the first time using containerized young plants grown outside. Three varieties were studied: 'West Coast Tall' (drought avoiding), 'Malayan Yellow Dwarf' (drought susceptible), and their progeny, the hybrid 'PB 121' (drought resistant). Leaf water status (relative water content, leaf water potential) and leaf gas exchange parameters (stomatal conductance to water vapor, net photosynthetic rate, and leaf internal CO2 concentration) were measured throughout a drying cycle induced by withholding watering. On fully hydrated plants, the sensitivity of stomata to atmospheric water vapor deficit was also investigated. In the three varieties, stomatal conductance to water vapor declined before leaf water status parameters were affected. The existence of a root-to-shoot communication system was proposed. Net photosynthetic rate was highly dependent on stomatal aperture, but nonstomatal factors also participated in the reduction of CO2 fixation. Since gas exchange rates were equally sensitive to drought in the three varieties, they could not be used as screening parameters for drought resistance. Under severe drought stress, both relative water content and leaf water potential differed significantly among populations. 'West Coast Tall' maintained a higher leaf water status than 'Malayan Yellow Dwarf'. Remarkably, the water status parameters of 'PB 121' were intermediate between those of the two parents. Similar ranking was obtained in experiments with excised leaflets. The high reproductibility of the results suggests that leaf water status parameters might be useful as early selection criteria for drought resistance in coconut palm. Key words: Cocos nucifera L., gas exchange, leaf water status parameters, water deficit, water relations.

scholarly journals Effects of potassium in Myracrodruon urundeuva, Libidibia ferrea and Mimosa tenuiflora seedlings under a short-term water déficit

2020 ◽  
Vol 9 (5) ◽  
pp. e97953269
Author(s):  
Ediglécia Pereira Almeida ◽  
Antonio Lucineudo de Oliveira Freire ◽  
Ivonete Alves Bakke ◽  
Cheila Deisy Ferreira ◽  
George Martins França ◽  
...  
Keyword(s):  
Gas Exchange ◽  
Water Deficit ◽  
Water Status ◽  
Water Regimes ◽  
Plastic Bags ◽  
Short Period ◽  
Severe Water Deficit ◽  
Relative Water ◽  
Black Plastic ◽  
Mimosa Tenuiflora

This study aimed to evaluate the effects of potassium fertilization on Myracrodruon urundeuva, Libidibia ferrea and Mimosa tenuiflora seedlings submitted to a short period of water deficit. Three doses of K (0, 150 and 300 mg dm-3 KCl) and three water regimes (without water deficit, moderate water deficit and severe water deficit) were evaluated. The plants were kept in black plastic bags containing soil from the Caatinga and, 30 days after the beginning of the water regimes, the relative water content (RWC), transpiration (E), stomatal conductance (gs) and photosynthesis (A) were evaluated. High moisture content in the soil was unfavorable to plants, promoting reduction in RWC and gas exchange. The water deficit increase E, gs and A, but the intensity of these responses was variable between species. The water deficit favored L. ferrea, with elevated RWC and reduced alterations in gas exchange, demonstrating its greater tolerance in relation to the others species evaluated, however it was the species most benefited by K. The supply of 300 mg dm-3 of KCl positively influenced the water status and gas exchange of the studied species with an increase in the water deficit. We suggest the development of research subjecting the plants to a longer period of time, in order to establish a better relationship between potassium and the increased tolerance of these plants to water deficit.

A new automated stem CO2 efflux chamber based on industrial ultra-low-cost sensors

2019 ◽  
Author(s):  
Johannes Brändle ◽  
Norbert Kunert
Keyword(s):  
Gas Exchange ◽  
Low Cost ◽  
Climatic Conditions ◽  
Co2 Efflux ◽  
Diurnal Changes ◽  
Lowland Forest ◽  
Stem Respiration ◽  
Stem Co2 Efflux ◽  
Gas Exchange System ◽  
Controlling Processes

Abstract Tree autotrophic respiratory processes, especially stem respiration or stem CO2 efflux (Estem), are important components of the forest carbon budget. Despite the efforts to investigate the controlling processes of Estem in the last years a considerable lack in our knowledge remains on the abiotic and biotic drivers affecting Estem dynamics. It has been strongly advocated that long-term measurements would shed light into those processes. The expensive scientific instruments needed to measure gas exchange has prevented from applying Estem measurements on a larger temporal and spatial scale. Here, we present an automated closed dynamic chamber system based on inexpensive and industrially broadly applied CO2 sensors reducing the costs for the sensing system to a minimum. The CO2 sensor was cross-calibrated with a commonly used gas exchange system in the laboratory and in the field, and we found very good accordance of these sensors. We tested the system under harsh tropical climatic conditions, characterized by heavy tropical rainfall events, extreme humidity, and temperatures, in a moist lowland forest in Malaysia. We recorded Estem of three Dyera costulata trees with our prototype over various days. The variation of Estem was large among the three tree individuals and varied by 7.5-fold. However, clear diurnal changes in Estem were present in all three tree individuals. One tree showed high diurnal variation in Estem and the relationship between Estem and temperature was characterized by a strong hysteresis. The large variations found within one single tree species highlights the importance of continuous measurement to quantify ecosystem carbon fluxes.

scholarly journals Growth, leaf and stomatal traits of crabwood (Carapa guianensis Aubl.) in central Amazonia

2012 ◽  
Vol 36 (1) ◽  
pp. 07-16 ◽  
Author(s):  
Miguel Angelo Branco Camargo ◽  
Ricardo Antonio Marenco
Keyword(s):  
Growth Rates ◽  
Stomatal Density ◽  
Leaf Gas Exchange ◽  
Carbon Assimilation ◽  
Leaf Traits ◽  
Leaf Thickness ◽  
Diurnal Changes ◽  
Wet Season ◽  
Carapa Guianensis ◽  
Rainfall Seasonality

Crabwood (Carapa guianensis Aubl.) is a fast growing tree species with many uses among Amazonian local communities. The main objective of this study was to assess the effect of seasonal rainfall pattern on growth rates, and seasonal and diurnal changes in leaf gas exchange and leaf water potential (ΨL) in crabwood. To assess the effect of rainfall seasonality on growth and physiological leaf traits an experiment was conducted in Manaus, AM (03º 05' 30" S, 59º 59' 35" S). In this experiment, six 6-m tall plants were used to assess photosynthetic traits and ΨL. In a second experiment the effect of growth irradiance on stomatal density (S D), size (S S) and leaf thickness was assessed in 0.8-m tall saplings. Stomatal conductance (g s) and light-saturated photosynthesis (Amax) were higher in the wet season, and between 09:00 and 15:00 h. However, no effect of rainfall seasonality was found on ΨL and potential photosynthesis (CO2-saturated). ΨL declined from -0.3 MPa early in the morning to -0.75 MPa after midday. It increased in the afternoon but did not reach full recovery at sunset. Growth rates of crabwood were high, and similar in both seasons (2 mm month-1). Leaf thickness and S D were 19% and 47% higher in sun than in shade plants, whereas the opposite was true for S S. We conclude that ΨL greatly affects carbon assimilation of crabwood by reducing g s at noon, although this effect is not reflected on growth rates indicating that other factors offset the effect of g s on Amax.

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