scholarly journals Isotopic and Water Relation Responses to Ozone and Water Stress in Seedlings of Three Oak Species with Different Adaptation Strategies

Forests ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 864
Author(s):  
Claudia Cocozza ◽  
Elena Paoletti ◽  
Tanja Mrak ◽  
Saša Zavadlav ◽  
Tom Levanič ◽  
...  
Keyword(s):  
Water Stress ◽  
Gas Exchange ◽  
Water Content ◽  
Leaf Gas Exchange ◽  
Water Relation ◽  
Adaptation Strategies ◽  
Leaf Water ◽  
Leaf Water Content ◽  
Global Changes ◽  
The Impact

The impact of global changes on forest ecosystem processes is based on the species-specific responses of trees to the combined effect of multiple stressors and the capacity of each species to acclimate and cope with the environment modification. Combined environmental constraints can severely affect plant and ecological processes involved in plant functionality. This study provides novel insights into the impact of a simultaneous pairing of abiotic stresses (i.e., water and ozone (O3) stress) on the responses of oak species. Water stress (using 40 and 100% of soil water content at field capacity—WS and WW treatments, respectively) and O3 exposure (1.0, 1.2, and 1.4 times the ambient concentration—AA, 1.2AA, and 1.4AA, respectively) were carried out on Quercus robur L., Quercus ilex L., and Quercus pubescens Willd. seedlings, to study physiological traits (1. isotope signature [δ13C, δ18O and δ15N], 2. water relation [leaf water potential, leaf water content], 3. leaf gas exchange [light-saturated net photosynthesis, Asat, and stomatal conductance, gs]) for adaptation strategies in a Free-Air Controlled Exposure (FACE) experiment. Ozone decreased Asat in Q. robur and Q. pubescens while water stress decreased it in all three oak species. Ozone did not affect δ13C, whereas δ18O was influenced by O3 especially in Q. robur. This may reflect a reduction of gs with the concomitant reduction in photosynthetic capacity. However, the effect of elevated O3 on leaf gas exchange as indicated by the combined analysis of stable isotopes was much lower than that of water stress. Water stress was detectable by δ13C and by δ18O in all three oak species, while δ15N did not define plant response to stress conditions in any species. The δ13C signal was correlated to leaf water content (LWC) in Q. robur and Q. ilex, showing isohydric and anisohydric strategy, respectively, at increasing stress intensity (low value of LWC). No interactive effect of water stress and O3 exposure on the isotopic responses was found, suggesting no cross-protection on seasonal carbon assimilation independently on the species adaptation strategy.

Methodological aspects and experimental conditions in the use of fluorescence as an index of water stress in cut leaves from genus Vitis

OENO One ◽  
1992 ◽  
Vol 26 (3) ◽  
pp. 163
Author(s):  
Francesco Iacono ◽  
Massimo Bertamini ◽  
Tardáguila Javier
Keyword(s):  
Water Stress ◽  
Water Content ◽  
Fluorescence Emission ◽  
Leaf Water ◽  
Leaf Water Content ◽  
Variable Fluorescence ◽  
Experimental Conditions ◽  
Breeding Programmes ◽  
Methodological Aspects ◽  
Cut Leaves

<p style="text-align: justify;">Fluorescence emission is linked to leaf physiological conditions. In particular water stress modifies emission curves strongly. But fluorescence is also influenced by some factors which usually arise in experimental vine breeding programmes. The present research studies some variables that usually characterize the trials on genus <em>Vitis</em>: rootstocks and graftings.</p><p style="text-align: justify;">The time of measurement is very important and the fluorescence variables (absolute value) are not correlated with leaf water content. It needs a standardisation by time. The gross relation between fluorescence (after standardisation) and RWC is significant but it is modified by the rootstock behaviour. The Variable Fluorescence is strongly linked to leaf water content, even though the Maximum rate of Fluorescence Quenching shows a variable correlation with decreasing RWC. The genotype controls that variable better than Variable Fluorescence.</p>

scholarly journals Comparison of Strawberry F. chilocnsis and F. ×ananassa in Response to Water Stress: I. Leaf Water Potential, Relative Water Content, and Gas Exchange Characteristics

HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 601c-601
Author(s):  
Chuhe Chen ◽  
J. Scott Cameron ◽  
Stephen F. Klauer
Keyword(s):  
Water Stress ◽  
Gas Exchange ◽  
Water Potential ◽  
Water Content ◽  
Leaf Water Potential ◽  
Relative Water Content ◽  
Leaf Water ◽  
Severe Water Stress ◽  
Relative Water ◽  
Gas Exchange Characteristics

Leaf water potential (LWP), relative water content (RWC), gas exchange characteristics, and specific leaf weight (SLW) were measured six hours before, during, and after water stress treatment in F. chiloensis and F. ×ananassa grown in growth chambers. The leaves of both species showed significantly lower LWP and RWC as water stress developed. F. ×ananassa had consistency lower LWP under stressed and nonstressed conditions than F. chiloensis. F. ×ananassa had higher RWC under nonstressed conditions, and its RWC decreased more rapidly under water stress than F. chiloensis. In comparison to F. ×ananassa, F. chiloensis had significantly higher CO2 assimilation rate (A), leaf conductance (LC), and SLW, but not transpiration rate (Tr), under stressed and nonstressed conditions. LC was the most sensitive gas exchange characteristic to water stress and decreased first. Later, A and stomatal conductance were reduced under more severe water stress. A very high level of Tr was detected in F. ×ananassa under the most severe water stress and did not regain after stress recovery, suggesting a permanent damage to leaf. The Tr of F. chiloensis was affected less by water stress. Severe water stress resulted in higher SLW of both species.

scholarly journals Leaf Water Relation Parameters in Almond Compared to Hazelnut Trees during a Deficit Irrigation Period

1997 ◽  
Vol 122 (4) ◽  
pp. 582-587 ◽  
Author(s):  
Jordi Marsal ◽  
Joan Girona ◽  
Mercè Mata
Keyword(s):  
Gas Exchange ◽  
Deficit Irrigation ◽  
Leaf Gas Exchange ◽  
Prunus Dulcis ◽  
Early Morning ◽  
Water Relation ◽  
Leaf Water ◽  
Assimilation Rate ◽  
Gas Exchange Parameters ◽  
Irrigation Treatments

The influence of deficit irrigation on predawn leaf water potential (Ψpd) and leaf gas-exchange parameters was analyzed in almond [Prunus dulcis (Mill.) D.A. Webb] and compared to hazelnut (Corylus avellana L.). Both species were planted in adjacent plots in which four irrigation treatments were applied: T-100%, T-130%, and T-70%, which were irrigated at full crop evapotranspiration (ETc), 1.3 × ETc, and 0.7 × ETc, respectively, and a regulated deficit irrigation (RDI) treatment, which consisted of full irrigation for the full season, except from middle June to late August when 0.2 × ETc was applied. Under nonstressful conditions, hazelnut had a lower net CO2 assimilation rate (A) (12.2 μmol·m-2·s-1) than almond (15.5 μmol·m-2·s-1). Reductions in net CO2 assimilation rate (A) induced by decreases in Ψpd were higher in hazelnut than in almond. Gas-exchange activity from early morning to midday decreased in hazelnut for all irrigation treatments, but in almond increased in the well-watered treatments and decreased slightly or remained constant in the RDI. Hazelnut had a higher A sensitivity to variations in stomatal conductance (gs) than almond, especially at low gs values. The Ψpd values in almond and hazelnut of the T-100% and T-130% treatments were affected by decreasing values in midsummer, but in hazelnut Ψpd was probably also affected by sink kernel filling. These facts indicate that hazelnut RDI management could be more problematic than in almond.

scholarly journals Osmotic Potential, Sucrose Level, and Activity of Sucrose Metabolic Enzymes in Tall Fescue in Response to Deficit Irrigation

2010 ◽  
Vol 135 (6) ◽  
pp. 506-510 ◽  
Author(s):  
Jinmin Fu ◽  
Bingru Huang ◽  
Jack Fry
Keyword(s):  
Drought Stress ◽  
Water Content ◽  
Tall Fescue ◽  
Osmotic Potential ◽  
Deficit Irrigation ◽  
Leaf Water ◽  
Leaf Water Content ◽  
Severe Drought ◽  
The Impact ◽  
Sucrose Level

Effects of deficit irrigation applied to home lawns, used as means of water conservation, are an important issue. However, the impact of deficit irrigation on sucrose metabolism in tall fescue (Festuca arundinacea) is unknown and important because sucrose is the dominant form of carbohydrate transported to developing plant organs. The objectives of this study were to investigate the effects of deficit irrigation on leaf water content, osmotic potential (ψS), sucrose level, and the activity of sucrose phosphate synthase (SPS; EC 2.4.1.14), sucrose synthase (SS; EC 2.4.1.13), and acid invertase (AI; EC 3.2.1.26) in tall fescue leaves. Sods of ‘Falcon II’ tall fescue were established in polyvinylchloride (PVC) tubes (10 cm diameter × 40 cm long) filled with a mixture of sand and fritted clay [9:1 (v:v)] and then placed in growth chambers. Reference evapotranspiration rate [ETo (millimeters of water per day)] was determined by weighing the PVC tubes containing well-watered turfgrass every 3 days to determine water loss on a daily basis as ETo. Deficit irrigation treatments were applied as follows: well-watered control, mild drought stress (60% ETo), and severe drought stress (20% ETo). Leaf water content was lower at 6, 12, and 20 days of treatment for the 20% ETo treatment and 20 days after treatment began for the 60% ETo treatment. Compared with the well-watered control, ψS was lower in the 60% ETo treatment on all three measurement dates. Sucrose was higher at 8 and 14 days after treatment began in the 60% ETo treatment and on all three measurement dates in the 20% ETo treatment relative to the well-watered control. No difference in sucrose level was observed between the 20% ETo and 60% ETo irrigation regimes at 8 and 14 days of treatment. Beginning 14 days after treatment, tall fescue had a higher level of SPS in the 60% ETo and 20% ETo treatments compared with the well-watered treatment. Tall fescue receiving 60% or 20% ETo had a lower level of AI activity on all measurement dates. Results suggest that the decrease in ψS was accompanied by higher sucrose levels, which were the result of the increased level of SPS and SS activity and a decline in AI activity.

scholarly journals Evaluation of Resistance of Winter Wheat to Fusarium acuminatum by Inoculation of Seedling Roots with Single, Germinated Macroconidia

Plant Disease ◽  
1998 ◽  
Vol 82 (3) ◽  
pp. 300-302 ◽  
Author(s):  
M. Mergoum ◽  
J. P. Hill ◽  
J. S. Quick
Keyword(s):  
Water Stress ◽  
Winter Wheat ◽  
Water Content ◽  
Root Rot ◽  
Leaf Water ◽  
Leaf Water Content ◽  
Ion Leakage ◽  
Wheat Cultivars ◽  
Fusarium Acuminatum ◽  
Seedling Roots

Fusarium acuminatum is one of the causal agents of dryland root rot of winter wheat in Colorado. The effect of F. acuminatum seedling root infection, recorded at heading, on winter wheat cultivars Sandy and CO84 was investigated in the greenhouse. Winter wheat seeds were surface disinfested, germinated, and vernalized. Vernalized seedling roots were inoculated by placing a single, germinated macroconidium of F. acuminatum on the largest root. Inoculated and non-inoculated vernalized seedlings were transplanted to pots and half the plants subjected to water stress. Inoculated plants had significantly lower survival rates and, at maturity, lower relative leaf water content, fewer tillers, shorter plant height, and higher cell ion leakage than non-inoculated plants. Wheat cultivars differed significantly for most traits studied. CO84 was susceptible whereas Sandy was more tolerant of the pathogen, particularly under water stress conditions. These results suggest that relative leaf water content, cell ion leakage, and to some extent seedling survival may be useful attributes for evaluation of resistance to the root rot pathogen.

scholarly journals Impact of Rice Husk Biochar on Growth, Water Relations and Yield of Maize (Zea mays L.) under Drought Condition

2018 ◽  
Vol 16 (02) ◽  
pp. 93-101 ◽  
Author(s):  
MA Shashi ◽  
MA Mannan ◽  
MM Islam ◽  
MM Rahman
Keyword(s):  
Water Content ◽  
Water Relations ◽  
Rice Husk ◽  
Water Relation ◽  
Leaf Water Content ◽  
Drought Condition ◽  
Relative Water ◽  
Rice Husk Biochar ◽  
The Impact ◽  
Different Doses

The present experiment was conducted to study the impact of rice husk biochar on growth, water relations and yield of maize (BARI Hybrid Bhutta- 9) under drought (60 and 40% of FC) conditions. Four doses of rice husk biochar @ 0, 5, 10 and 20 t/ha were applied as an amendment in soil before sowing of seeds. Results revealed that drought stress reduced plant height, relative water content and grain yield of maize. But rice husk biochar at different doses improved the above mentioned characters under drought conditions. Under 60% of FC, the highest plan height, leaf water content and yield were 196.67 cm, 79.86% and 89.75 g/plant, respectively when biochar was applied @ 20 t/ha but it was 173.33 cm, 78.32% and 84.57 g/plant, respectively under 40% of FC when biochar was applied at the same dose. It may be concluded that, rice husk biochar @ 20 t/ha showed the best result to promote growth, water relation traits and yield of maize under drought condition. The Agriculturists 2018; 16(2) 93-101

scholarly journals Grafting cv. Grechetto Gentile Vines to New M4 Rootstock Improves Leaf Gas Exchange and Water Status as Compared to Commercial 1103P Rootstock

Agronomy ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 708 ◽  
Author(s):  
Tommaso Frioni ◽  
Arianna Biagioni ◽  
Cecilia Squeri ◽  
Sergio Tombesi ◽  
Matteo Gatti ◽  
...  
Keyword(s):  
Water Stress ◽  
Gas Exchange ◽  
Water Use ◽  
Leaf Gas Exchange ◽  
Water Status ◽  
Stomatal Closure ◽  
Leaf Water ◽  
Summer Drought ◽  
Co2 Uptake ◽  
Drought Tolerant

M4 is a relatively new rootstock that was selected for increased resilience of vineyards across hot regions where meteorological drought is often coupled to water scarcity. However, M4 has thus far been tested only against water-stress sensitive rootstocks. Against this backdrop, the aim of the present work is to examine the water status and gas exchange performances of vines grafted to M4 in comparison to those of vines grafted to a commercial stock that is drought-tolerant, 1103 Paulsen (1103P), under a progressive water deficit followed by re-watering. This study was undertaken on Grechetto Gentile, a cultivar that is renowned for its rather conservative water use (near-isohydric behavior). While fifty percent of both grafts were fully irrigated (WW), the remaining underwent progressive water stress by means of suspending irrigation (WS). Soil and leaf water status, as well as leaf gas exchanges, along with chlorophyll fluorescence, were followed daily from 1 day pre-stress (DOY 176) until re-watering (DOY 184). Final leaf area per vine, divided in main and lateral contribution, was also assessed. While 1103P grafted vines manifested higher water use under WW conditions, progressive stress evidenced a faster water depletion by 1103P, which also maintained slightly more negative midday leaf water potential (Ψleaf) as compared to M4 grafted plants. Daily gas exchange readings, as well as diurnal assessment performed at the peak of stress (DOY 183), also showed increased leaf assimilation rates (A) and water use efficiency (WUE) in vines grafted on M4, which were also less susceptible to photosynthetic downregulation. Dynamic of stomatal closure targeted at 90% reduction of leaf stomatal conductance showed a similar behavior among rootstocks since the above threshold was reached by both at Ψleaf of about −1.11 MPa. The same fractional reduction in leaf A was reached by vines grafted on M4 at a Ψleaf of −1.28 MPa vs. −1.10 MPa measured in 1103P, meaning that using M4 as a rootstock will postpone full stomatal closure. While mechanisms involved in improved CO2 uptake in M4-grafted vines under moderate-to-severe stress are still unclear, our data support the hypothesis that M4 might outscore the performance of a commercial drought-tolerant genotype (1103P) and can be profitably used as a tool to improve the resilience of vines to summer drought.

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