scholarly journals Effects of Abscisic Acid on Drought Responses of Kentucky Bluegrass

2003 ◽  
Vol 128 (1) ◽  
pp. 36-41 ◽  
Author(s):  
Zhaolong Wang ◽  
Bingru Huang ◽  
Qingzhang Xu
Keyword(s):  
Abscisic Acid ◽  
Drought Stress ◽  
Osmotic Adjustment ◽  
Foliar Application ◽  
Poa Pratensis ◽  
Turgor Pressure ◽  
Photochemical Efficiency ◽  
Kentucky Bluegrass ◽  
Exogenous Aba ◽  
Turf Quality

Abscisic acid (ABA) is an important hormone regulating plant response to drought stress. The objective of this study was to investigate effects of exogenous ABA application on turf performance and physiological activities of kentucky bluegrass (Poa pratensis L.) in response to drought stress. Plants of two kentucky bluegrass cultivars, `Brilliant' (drought susceptible) and `Midnight' (drought tolerant), were treated with ABA (100 μm) or water by foliar application and then grown under drought stress (no irrigation) or well-watered (irrigation on alternate days) conditions in a growth chamber. The two cultivars responded similarly to ABA application under both watering regimes. Foliar application of ABA had no effects on turf quality or physiological parameters under well-watered conditions. ABA application, however, helped maintain higher turf quality and delayed the quality decline during drought stress, compared to the untreated control. ABA-treated plants exposed to drought stress had higher cell membrane stability, as indicated by less electrolyte leakage of leaves, and higher photochemical efficiency, expressed as Fv/Fm, compared to untreated plants. Leaf water potential was not significantly affected, whereas leaf turgor pressure increased with ABA application after 9 and 12 d of drought. Osmotic adjustment increased with ABA application, and was sustained for a longer period of drought in `Midnight' than in `Brilliant'. The results suggested that exogenous ABA application improved turf performance during drought in both drought-sensitive and tolerant cultivars of kentucky bluegrass. This positive effect of ABA could be related to increased osmotic adjustment, cell turgor maintenance, and reduced damage to cell membranes and the photosynthetic system.

scholarly journals Differential Effects of Abscisic Acid and Glycine Betaine on Physiological Responses to Drought and Salinity Stress for Two Perennial Grass Species

2012 ◽  
Vol 137 (2) ◽  
pp. 96-106 ◽  
Author(s):  
Zhimin Yang ◽  
Jingjin Yu ◽  
Emily Merewitz ◽  
Bingru Huang
Keyword(s):  
Abscisic Acid ◽  
Salinity Stress ◽  
Glycine Betaine ◽  
Foliar Application ◽  
Poa Pratensis ◽  
Kentucky Bluegrass ◽  
Grass Species ◽  
Antioxidant Metabolism ◽  
Positive Effects ◽  
Turf Quality

Abscisic acid (ABA) and glycine betaine (GB) may regulate plant responses to drought or salinity stress. The objectives of this controlled-environment study were to determine whether foliar application of ABA or GB improves turf quality under drought or salinity and whether improved stress responses were associated changes in antioxidant metabolism in two C3 turfgrass species, creeping bentgrass (Agrostis stolonifera) and kentucky bluegrass (Poa pratensis). Physiological parameters evaluated included turf quality, leaf relative water content, membrane electrolyte leakage (EL), membrane lipid peroxidation [expressed as malondialdehyde (MDA) content], and activity of superoxide dismutase (SOD), peroxidase (POD), and ascorbate peroxidase (APX). Abscisic acid and GB were both effective in mitigating physiological damage resulting from drought or salinity for both grass species, but effects were more pronounced on kentucky bluegrass. The most notable effects of ABA or GB application were the suppression of EL and MDA accumulation and an increase in APX, POD, and SOD activities after prolonged periods of drought (21 days) or salinity stress (35 days). These results suggest foliar application of ABA or GB may alleviate physiological damage by drought or salinity stress in turfgrass and the maintenance of membrane stability and active antioxidant metabolism could contribute to the positive effects in the stress mitigation effects.

scholarly journals Ultraviolet-B Radiation Damage on Kentucky Bluegrass II: Hormone Supplement Effects

HortScience ◽  
2004 ◽  
Vol 39 (6) ◽  
pp. 1471-1474 ◽  
Author(s):  
Erik H. Ervin ◽  
Xunzhong Zhang ◽  
John H. Fike
Keyword(s):  
Plant Defense ◽  
Catalase Activity ◽  
Foliar Application ◽  
Poa Pratensis ◽  
Photochemical Efficiency ◽  
Kentucky Bluegrass ◽  
Ultraviolet B ◽  
Alpha Tocopherol ◽  
Anthocyanin Content ◽  
Turf Quality

High ultraviolet-B (UV-B; 290-320 nm wavelength) radiation may significantly contribute to the quality decline and death of kentucky bluegrass (Poa pratensis L.) sod during summer transplanting. Antioxidants and protective pigments may be involved in plant defense against oxidative stress caused by UV-B. Selected exogenous hormones may alleviate UV-B damage by upregulating plant defense systems. The objectives of this study were to determine if exogenous hormone or hormone-like substances could alleviate UV-B damage to `Georgetown' kentucky bluegrass (Poa pratensis L.) under greenhouse conditions. The hormone salicylic acid at 150 mg·m-2 and the hormone-containing substances, humic acid (HA) at 150 mg·m-2 and seaweed extract (SWE) at 50 mg·m-2, were applied to plugs of kentucky bluegrass and then subjected to UV-B radiation (70 μmol·m-2·s-1). The UV-B irradiation stress reduced turf quality by 51% to 66% and photochemical efficiency by 63% to 68% when measured 10 or 12 days after initiation of UV-B. Endogenous alpha-tocopherol (AT) and antioxidant enzymes (superoxide dismutase (SOD) and catalase) were reduced by UV-B stress. Anthocyanin content was increased from day 1 to 5 and then decreased from day 5 to 10 of continuous UV-B irradiation. Application of SA and HA + SWE enhanced photochemical efficiency by 86% and 82%, respectively, when measured 10 or 12 days after UV-B initiation. In addition, application of the hormonal supplements increased AT concentration, SOD, catalase activity, and anthocyanin content when compared to the control at 10 days after UV-B initiation. Bluegrass with greater AT concentration and SOD and catalase activity exhibited better visual quality under UV-B stress. The results of this study suggest that foliar application of SA and HA + SWE may alleviate decline of photochemical efficiency and turf quality associated with increased UV-B light levels during summer.

scholarly journals Silicon Application Increases Drought Tolerance of Kentucky Bluegrass by Improving Plant Water Relations and Morphophysiological Functions

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Shah Saud ◽  
Xin Li ◽  
Yang Chen ◽  
Lu Zhang ◽  
Shah Fahad ◽  
...  
Keyword(s):  
Drought Stress ◽  
Drought Tolerance ◽  
Water Relations ◽  
Poa Pratensis ◽  
Kentucky Bluegrass ◽  
Leaf Water ◽  
Leaf Water Content ◽  
Plant Water Relations ◽  
Plant Water ◽  
Turf Quality

Drought stress encumbers the growth of turfgrass principally by disrupting the plant-water relations and physiological functions. The present study was carried out to appraise the role of silicon (Si) in improving the drought tolerance in Kentucky bluegrass (Poa pratensisL.). Drought stress and four levels (0, 200, 400, and 800 mg L−1) of Si (Na2SiO3·9H2O) were imposed after 2 months old plants cultured under glasshouse conditions. Drought stress was found to decrease the photosynthesis, transpiration rate, stomatal conductance, leaf water content, relative growth rate, water use efficiency, and turf quality, but to increase in the root/shoot and leaf carbon/nitrogen ratio. Such physiological interferences, disturbances in plant water relations, and visually noticeable growth reductions in Kentucky bluegrass were significantly alleviated by the addition of Si after drought stress. For example, Si application at 400 mg L−1significantly increased the net photosynthesis by 44%, leaf water contents by 33%, leaf green color by 42%, and turf quality by 44% after 20 days of drought stress. Si application proved beneficial in improving the performance of Kentucky bluegrass in the present study suggesting that manipulation of endogenous Si through genetic or biotechnological means may result in the development of drought resistance in grasses.

scholarly journals Drought Responses of Kentucky Bluegrass and Creeping Bentgrass as Affected by Abscisic Acid and Trinexapac-ethyl

2008 ◽  
Vol 133 (1) ◽  
pp. 20-26 ◽  
Author(s):  
Stephen E. McCann ◽  
Bingru Huang
Keyword(s):  
Abscisic Acid ◽  
Drought Stress ◽  
Water Content ◽  
Water Relations ◽  
Growth Rates ◽  
Untreated Control ◽  
Foliar Application ◽  
Creeping Bentgrass ◽  
Kentucky Bluegrass ◽  
Vertical Growth

The plant growth regulators abscisic acid (ABA) and trinexapac-ethyl (TE) may affect turfgrass responses to drought stress through regulating shoot growth and water relations. The objectives of this study were to investigate the effects of foliar application of TE and ABA on turf growth of two cool-season turfgrass species, Kentucky bluegrass (Poa pratensis L.) and creeping bentgrass (Agrostis stolonifera L.) exposed to drought stress, and to examine water relations associated with changes in drought tolerance due to TE or ABA treatment. ‘L-93’ creeping bentgrass and ‘Brilliant’ Kentucky bluegrass plants were foliar sprayed with 0.904 mL·ha−1 a.i. TE five times before exposure to drought or with 6.75 mL/week of ABA at 100 μm before and after exposure to drought in growth chambers. Drought stress was imposed by withholding irrigation until plants were permanently wilted. Foliar application of TE or ABA maintained higher soil volumetric water content, leaf relative water content, and turf quality for a longer period of time during 28 days of stress exposure for Kentucky bluegrass and creeping bentgrass compared with the untreated control. Leaves of TE-treated and ABA-treated plants in both species also had lower ψS at 28 days of drought stress than the untreated control. Creeping bentgrass treated with TE or ABA and Kentucky bluegrass treated with TE exhibited significantly lower shoot vertical growth rates at the initiation of drought stress, but maintained higher growth rates during prolonged drought compared with the untreated control. Turf treated with TE or ABA also showed higher levels of photochemical efficiency than the untreated control for both species. Our results suggest that TE or ABA application could prolong the survival of turfgrass under conditions of drought stress by suppressing shoot vertical growth and lowering water use during the early phase of drought and by sustaining growth and photosynthetic activity during prolonged periods of drought stress through osmotic adjustment for retaining cellular hydration.

scholarly journals Genotypic Variation in Abscisic Acid Accumulation, Water Relations, and Gas Exchange for Kentucky Bluegrass Exposed to Drought Stress

2003 ◽  
Vol 128 (3) ◽  
pp. 349-355 ◽  
Author(s):  
Zhaolong Wang ◽  
Bingru Huang
Keyword(s):  
Abscisic Acid ◽  
Drought Stress ◽  
Gas Exchange ◽  
Water Relations ◽  
Drought Resistance ◽  
Accumulation Rate ◽  
Kentucky Bluegrass ◽  
Stress Conditions ◽  
Turf Quality ◽  
Aba Content

Drought is a major limiting factor for turfgrass growth. Understanding genetic variations in physiological responses of turfgrass to drought stress would facilitate breeding and management programs to improve drought resistance. This study was designed to evaluate responses of abscisic acid (ABA) accumulation, water relations, and gas exchange to drought stress in four Kentucky bluegrass (Poa pratensis L.) cultivars differing in drought resistance. Plants of `Midnight' and `A82-204' (drought resistant) and `Brilliant' and `RSP' (drought susceptible) were grown under well-watered (control) or drought stress conditions for 25 days in growth chambers. Turf quality, leaf water potential (Ψleaf), relative water content (RWC), leaf net photosynthesis rate (Pn), and stomatal conductance (gs) declined, while electrolyte leakage (EL) increased during drought progression in all cultivars. The magnitudes of the change in these parameters were greater for `RSP' and `Brilliant' than for `Midnight' and `A82-204'. Leaf ABA content in `RSP' and `Brilliant' increased sharply after 2 days of stress to as much as 34 times the control level at 10 days of drought. Leaf ABA content in `Midnight' and `A82-204' also increased with drought, but to a lesser extent than in the other two cultivars. Leaf ABA level was negatively correlated with Ψleaf and gs. `A82-204' had a significantly lower ABA accumulation rate with changes in Ψleaf during drought compared to `Midnight', `RSP' and `Brilliant'; however, no differences in ABA accumulation rate were detected among the latter three cultivars. In addition, leaf gs was more sensitive to changes in ABA accumulation in `Midnight' and `A82-204' than in `RSP' and `Brilliant'. These results demonstrated that drought tolerant cultivars of Kentucky bluegrass were characterized by lower ABA accumulation and less severe decline in Ψleaf, Pn, gs, and turf quality during drought stress than drought sensitive cultivars. Drought tolerance of Kentucky bluegrass could be related to sensitivity of stomata to endogenous accumulation of ABA under drought stress conditions.

scholarly journals Ultraviolet-B Radiation Damage on Kentucky Bluegrass. III. Cultivar Effects

HortScience ◽  
2004 ◽  
Vol 39 (6) ◽  
pp. 1475-1477 ◽  
Author(s):  
Erik H. Ervin ◽  
Xunzhong Zhang ◽  
John H. Fike
Keyword(s):  
Chlorophyll A ◽  
Defense Mechanisms ◽  
Poa Pratensis ◽  
Photochemical Efficiency ◽  
Correlation Coefficients ◽  
Kentucky Bluegrass ◽  
Ultraviolet B ◽  
Antioxidant Systems ◽  
Turf Quality ◽  
Antioxidant Defense Systems

Plants possess various constitutive and inducible defense mechanisms such as pigment and antioxidant systems for protection against stresses such as ultraviolet-B (UV-B; 290 to 320 nm) radiation. Our previous research has indicated that higher chlorophyll, carotenoid, and anthocyanin concentrations were associated with greater tolerance of UV-B stress by `Georgetown' kentucky bluegrass (Poa pratensis L.). The objectives of this study were to determine if kentucky bluegrass cultivars with darker leaf color possessed greater pigment and antioxidant defense systems and if such increases were associated with greater resistance to UV-B. Eight cultivars exhibiting a range of green color intensity (`Apollo', `Brilliant', `Julius', Limerick', `Midnight', `Moonlight', `Nuglade', and `Total Eclipse') were selected and subjected to continuous, artificial UV-B radiation (70 μmol·m-2·s-1). UV-B irradiation reduced turf quality (55% to 62%) and photochemical efficiency (37% to 70%) when measured 5 days after initiation of UV-B exposure. Significant differences in turf color, photochemical efficiency, chlorophyll a, chlorophyll b, chlorophyll a+b, and carotenoids were found among the cultivars. `Moonlight' had greatest photochemical efficiency, chlorophyll, carotenoids, and turf quality. Positive correlations of pigment concentration with photochemical efficiency and turf color were observed under UV-B radiation stress, with correlation coefficients ranging from 0.49 to 0.62. The results of this study suggests that selecting cultivars with higher concentrations of chlorophyll and carotenoids and photochemical efficiency may be an effective way for turfgrass managers and sod producers to improve sod establishment and quality in environments with higher UV-B radiation.

scholarly journals Drought Resistance and Recovery of Kentucky Bluegrass (Poa pratensis L.) Cultivars under Different Nitrogen Fertilisation Rates

Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1128
Author(s):  
Cristina Pornaro ◽  
Michele Dal Maso ◽  
Stefano Macolino
Keyword(s):  
Drought Stress ◽  
Poa Pratensis ◽  
Recovery Period ◽  
Kentucky Bluegrass ◽  
Recovery Phase ◽  
First Year ◽  
Cool Season ◽  
Nitrogen Fertilisation ◽  
Turf Quality ◽  
Green Cover

Kentucky bluegrass (Poa pratensis L.) is one of the most popular cool-season turfgrass species. However, little is known about the effects of N supply on its resistance to drought stress. The objective of this study was to assess the effects of acute drought followed by a recovery period on four Kentucky bluegrass cultivars (‘Barduke’, ‘Brooklawn’, ‘NuBlue Plus’ and ‘Marauder’) and one tall fescue (‘Rhambler SRP’) under two different nitrogen fertilisation rates (100 or 200 kg N ha−1 yr−1). The study was conducted over two years in a rain-out structure to control water input in spring and summer. The cultivars were subjected to a drought stress phase (absence of irrigation) followed by a recovery phase (weekly irrigation with an intake of 80% of ET). The green cover percentage, visual quality, NDVI, and soil moisture were measured weekly. We found that Kentucky bluegrass maintains sufficient turf quality for 2 weeks without irrigation. During the first year of the experiment, slight differences were observed among the Kentucky bluegrass cultivars, with ‘Marauder’ showing a 15% of green turf cover less than ‘Brooklawn’ after 6 weeks of acute drought, while in the second year, ‘NuBlue Plus’ displayed higher green turf cover and NDVI than the other cultivars. Nitrogen treatment had limited influence on the performances of the cultivars, ‘Marauder’ being the only one benefitting from the higher rate of applications.

scholarly journals Abscisic Acid Accumulation in Relation to Drought Tolerance in Kentucky Bluegrass

HortScience ◽  
2004 ◽  
Vol 39 (5) ◽  
pp. 1133-1137 ◽  
Author(s):  
Zhaolong Wang ◽  
Bingru Huang ◽  
Stacy A. Bonos ◽  
William A. Meyer
Keyword(s):  
Drought Stress ◽  
Drought Tolerance ◽  
Electrolyte Leakage ◽  
Poa Pratensis ◽  
Net Photosynthesis ◽  
Kentucky Bluegrass ◽  
Drought Duration ◽  
Turf Quality ◽  
Relative Water ◽  
Aba Content

Drought is a major factor limiting plant growth, which has been associated with the accumulation of absicsic acid (ABA) in various species. The objective of the study was to determine the relationship between ABA accumulation and drought tolerance for kentucky bluegrass (Poa pratensis L.) during short-term drought stress. Eight kentucky bluegrass cultivars (`Midnight', `A82-204', `RSP', `Alpine', `Moonlight', `Brilliant', `Washington', and `Baruzo') were subjected to drought stress in a growth chamber. Water relations, gas exchange rate, and ABA content of leaves were determined at various times during drought stress. Turf quality decreased with drought duration for all eight cultivars. Leaf ABA content increased linearly with drought stress within 11 days of treatment; the rate of the increase was negatively related to the rate of turf quality decline. The rate of ABA accumulation during drought stress was positively correlated with the rates of decrease in turf quality (r2 = 0.6346), increase in electrolyte leakage (r2 = 0.7128), and decrease in relative water content (r2 = 0.5913). There were highly significant negative correlations between ABA content and leaf water potential (r2 = 0.9074), stomatal conductance (r2 = 0.6088), transpiration rate (r2 = 0.6581), net photosynthesis rate (r2 = 0.6956), and a positive correlation between ABA content and electrolyte leakage (r2 = 0.7287). The results indicate that drought tolerance is negatively related to ABA accumulation during shortterm drought stress. ABA accumulation in response to drought stress could be used as a metabolic factor to select for drought tolerance in kentucky bluegrass.

scholarly journals Growth and Physiological Factors Involved in Interspecific Variations in Drought Tolerance and Postdrought Recovery in Warm- and Cool-season Turfgrass Species

2015 ◽  
Vol 140 (5) ◽  
pp. 459-465 ◽  
Author(s):  
Jingjin Yu ◽  
Mengxian Liu ◽  
Zhimin Yang ◽  
Bingru Huang
Keyword(s):  
Drought Stress ◽  
Drought Tolerance ◽  
Poa Pratensis ◽  
Warm Season ◽  
Kentucky Bluegrass ◽  
Cool Season ◽  
Physiological Factors ◽  
Zoysia Matrella ◽  
Turf Quality ◽  
Relative Water

Drought stress is one of the most important abiotic stresses limiting plant growth, while high recuperative capacity of plants from drought damages is critical for plant survival in periods of drought stress and rewatering. The objective of our study was to determine physiological and growth factors in association with drought tolerance and recuperative capacity of cool-season kentucky bluegrass (Poa pratensis cv. Excursion II) and warm-season zoysigrass (Zoysia matrella cv. Diomand), which were grown in controlled environment chambers and maintained well watered (control) or subjected to drought stress and subsequently rewatering. Compared with kentucky bluegrass, zoysiagrass maintained higher leaf hydration level during drought stress, as shown by greater relative water content (RWC), improved osmotic adjustment (OA), increased leaf thickness, and more extensive root system at deeper soil layers. Turf quality (TQ) and photosynthesis recovered to a greater level and sooner in response to rewatering for zoysiagrass, compared with kentucky bluegrass, which could be due to more rapid reopening of stomata [higher stomatal conductance (gS)] and leaf rehydration (higher RWC). The aforementioned physiological factors associated with leaf dehydration tolerance during drought and rapid resumption in turf growth and photosynthesis in zoysiagrass could be useful traits for improving drought tolerance in turfgrasses.

scholarly journals The Role of Leaf Pigment and Antioxidant Levels in UV-B Resistance of Dark- and Light-green Kentucky Bluegrass Cultivars

2005 ◽  
Vol 130 (6) ◽  
pp. 836-841 ◽  
Author(s):  
Xunzhong Zhang ◽  
E.H. Ervin ◽  
R.E. Schmidt
Keyword(s):  
Poa Pratensis ◽  
Plant Stress ◽  
Photochemical Efficiency ◽  
Kentucky Bluegrass ◽  
Ultraviolet B ◽  
Turf Quality ◽  
Dark Green ◽  
Major Factors ◽  
Artificial Uv ◽  
Light Green

Ultraviolet-B [UV-B (280-320 nm)] radiation is one of the major factors causing quality decline of transplanted sod. Pigments and antioxidants are associated with plant stress resistance, but their roles in turfgrass tolerance to UV-B damage are not well understood. The objectives of this study were to determine if kentucky bluegrass (Poa pratensis L.) cultivars with darker green genetic leaf color possessed greater pigment and antioxidant defense capacities and if such characteristics were associated with greater resistance to UV-B. Two cultivars, `Moonlight' (dark green) and `Limerick' (light green), were selected and subjected to continuous, artificial UV-B radiation (70 μmol·m-2·s-1). UV-B irradiation reduced turf quality by 58% (`Moonlight') and 77% (`Limerick') relative to day 1 when measured 10 days after initiation of UV-B exposure. Higher canopy photochemical efficiency (PEc) was found in `Moonlight' relative to `Limerick' under UV-B stress and during recovery. `Moonlight' contained greater levels of chlorophyll (1.5 to1.6-fold), carotenoids (1.3-fold), superoxide dismutase [SOD (1.0-fold)] and catalase [CAT (1.5-fold)] than `Limerick' when measured at 10 days after UV-B initiation. Turfgrass quality and PEc were positively correlated with pigments (chlorophyll and carotenoids) and antioxidant enzymes (SOD and CAT), and negatively correlated with lipid peroxidation. The results suggest that selecting dark-green cultivars with greater pigment content and antioxidant activity may be an effective approach for turfgrass breeders and sod producers to improve tolerance of newly transplanted sod to environments with higher UV-B radiation.

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