Differential Responses of Nutrients to Heat Stress in Warm-season and Cool-season Turfgrasses

The objective of this study was to compare differential nutrient responses to heat stress in relation to heat tolerance for warm-season (C4) common bermudagrass [Cynodon dactylon (L.) Pers.] and cool-season (C3) kentucky bluegrass (Poa pratensis L.). Both species were exposed to two temperature regimes in growth chambers: optimal day/night temperature conditions (24/20 °C for kentucky bluegrass and 34/30 °C for bermudagrass) or heat stress (10 °C above the respective optimal temperature for each species). Heat injury in leaves was evaluated and the concentrations of several major macronutrients [nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg)] in both grass species were measured at 0, 7, 14, 21, and 28 days of treatment. Heat stress reduced leaf photochemical efficiency and cellular membrane stability in both species, but bermudagrass leaves exhibited less damage in these parameters than kentucky bluegrass. Heat stress caused a significant decline in N, P, and K concentration, beginning at 7 days in kentucky bluegrass, but had no significant effects on N, P, and K concentration in bermudagrass during the 28-day treatment period. The concentration of Ca and Mg increased under heat stress in both kentucky bluegrass and bermudagrass, but there were no significant differences between the species under optimal or high-temperature conditions, suggesting they were not involved in heat responses in either species. The differential responses of N, P, and K to heat stress could at least partially account for the differences in heat tolerance between the two species and demonstrate the importance of sufficient N, P, and K in turfgrass adaptation to heat stress.

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Differential Responses to Heat Stress in Activities and Isozymes of Four Antioxidant Enzymes for Two Cultivars of Kentucky Bluegrass Contrasting in Heat Tolerance

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.135.2.116 ◽

2010 ◽

Vol 135 (2) ◽

pp. 116-124 ◽

Cited By ~ 26

Author(s):

Yali He ◽

Bingru Huang

Keyword(s):

Antioxidant Enzymes ◽

Heat Stress ◽

Heat Tolerance ◽

Defense Mechanisms ◽

Poa Pratensis ◽

Kentucky Bluegrass ◽

Guaiacol Peroxidase ◽

Cool Season ◽

Chl A ◽

Antioxidant Mechanisms

Understanding antioxidant mechanisms for heat stress is important for improving heat tolerance in cool-season plant species. The objective of this study was to identify antioxidant enzymes associated with cultivar variations in heat tolerance in kentucky bluegrass (Poa pratensis) by comparing heat responses of activity and isoforms of antioxidant enzymes in two cultivars contrasting in heat tolerance. Plants of heat-tolerant ‘Eagleton’ and heat-sensitive ‘Brilliant’ were exposed to 20 °C (control) or 40 °C (heat stress) for 28 days in growth chambers. Chlorophyll (Chl) a content remained unchanged and Chl b content increased in ‘Eagleton’, while both of them decreased in ‘Brilliant’, and by 28 days, ‘Eagleton’ had significantly higher Chl a and b content than ‘Brilliant’. The activities of superoxide dismutase (SOD) were significantly higher in ‘Eagleton’ than in ‘Brilliant’ by 28 days of heat stress. An isozyme SOD2 was induced early during heat stress in ‘Eagleton’, while isozyme SOD3 degraded, to a lesser extent in ‘Eagleton’ than in ‘Brilliant’. Catalase (CAT) activity significantly increased in ‘Brilliant’ but remained constant in ‘Eagleton’, and ‘Brilliant’ had a significantly higher CAT activity and isozyme CAT1 than ‘Eagleton’ during heat stress. Significant increases in ascorbate peroxidase (APX) activities occurred under heat stress, to a greater extent in ‘Eagleton’, whereas isozymes did not exhibit difference between cultivars. Guaiacol-peroxidase (POD) activity declined during heat stress in both cultivars. The intensity of POD isozymes in ‘Brilliant’ remained constant, while ‘Eagleton’ showed a transient increases in POD1 at 7 days of heat stress. Our results indicated that antioxidant defense mechanisms for heat tolerance in kentucky bluegrass could be mainly associated with changes in activity and forms of isozymes of SOD for O2 scavenging and APX activity for H2O2 scavenging under heat stress.

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Differential Effectiveness of Doubling Ambient Atmospheric CO2 Concentration Mitigating Adverse Effects of Drought, Heat, and Combined Stress in Kentucky Bluegrass

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.139.4.364 ◽

2014 ◽

Vol 139 (4) ◽

pp. 364-373

Author(s):

Yali Song ◽

Bingru Huang

Keyword(s):

Heat Stress ◽

Poa Pratensis ◽

Relative Effectiveness ◽

Kentucky Bluegrass ◽

Grass Species ◽

Combined Stress ◽

Cool Season ◽

Positive Effects ◽

Effects Of Drought ◽

Drought And Heat Stress

Drought and heat stress can limit the growth of cool-season grass species, whereas doubling ambient CO2 has been shown to promote plant growth. The objectives of this study were to examine differential responses of shoot and root growth as well as photosynthesis and respiration to doubling ambient CO2 during drought or heat stress alone or the two stresses combined and to determine the relative effectiveness of doubling ambient CO2 in mitigating negative effects of drought or heat stress alone and in combination in a cool-season perennial grass species. Kentucky bluegrass (Poa pratensis cv. Baron) plants were exposed to ambient CO2 (400 μL·L−1) or doubling ambient CO2 (800 μL·L−1) concentrations while subjected to the following stress treatments in growth chambers: drought stress by withholding irrigation, heat stress (35 °C), or the combined two stresses for 28 days. Doubling ambient CO2 increased root and shoot growth as well as root/shoot ratio under all treatments. Doubling ambient CO2 enhanced leaf net photosynthetic rate (Pn) to a greater extent under drought or heat alone, whereas it reduced respiration rate (R), to a larger degree under heat and the combined stress, leading to a greater ratio of Pn/R. Doubling ambient CO2 mitigated adverse physiological effects of drought or heat stress alone, whereas fewer effects were observed under the combined drought and heat stress. The positive effects of doubling ambient CO2 were associated with the development of roots biomass and the maintenance of a positive carbon balance under either stress alone or the combined drought and heat stress.

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Differential Responses of Hybrid Bluegrass and Kentucky Bluegrass to Drought and Heat Stress

HortScience ◽

10.21273/hortsci.43.7.2191 ◽

2008 ◽

Vol 43 (7) ◽

pp. 2191-2195 ◽

Cited By ~ 10

Author(s):

Eleni M. Abraham ◽

William A. Meyer ◽

Stacy A. Bonos ◽

Bingru Huang

Keyword(s):

Heat Stress ◽

Heat Tolerance ◽

Transpiration Rate ◽

Soil Depth ◽

Poa Pratensis ◽

Kentucky Bluegrass ◽

Optimal Temperature ◽

Turf Quality ◽

Differential Responses ◽

Drought And Heat Stress

This study was designed to investigate differential responses of hybrids from Texas bluegrass (Poa arachnifera Torr.) × Kentucky bluegrass (Poa pratensis L.) (KBG) and KBG genotypes to drought and heat stress. Plants of two hybrids, ‘845’ and ‘BDF’, and two KBG genotypes (‘Midnight’ and ‘C-74’) were grown under optimal temperature (22/18 °C) and well-watered (control) or unwatered (drought) or superoptimal temperatures (35/30 °C; heat stress) conditions for 35 days in growth chambers. Under optimal conditions, the two hybrids and two KBG genotypes were not significantly different in turf quality, leaf photochemical efficiency expressed as chlorophyll fluorescence ratio (Fv/Fm), leaf net photosynthetic rate (Pn), transpiration rate, water use efficiency (WUE), root dry matter, or root viability. The results suggest that the interspecific hybridization resulted in similar growth and physiological traits in the hybrid bluegrass as in a turf-type species under optimal temperature and irrigation regimes. Under drought stress, all these parameters were comparable to those for KBG ‘Midnight’, but significantly higher than the corresponding parameters for KBG ‘C-74’. Under heat stress, both hybrids had significantly higher turf quality, Fv/Fm, Pn, transpiration rate, WUE, root dry weight in deeper soil depth (40 to 60 cm), and root viability in the upper 40-cm layer compared with both KBG genotypes. These results suggested that hybrid bluegrass exhibited improvement in drought and heat tolerance, particularly in comparison with KBG ‘C-74’, but to a great extent for heat tolerance. The maintenance of higher transpiration and photosynthesis, WUE, and root viability was associated with the improvement in heat tolerance in hybrid bluegrass.

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Antioxidant and Hormone Responses to Heat Stress in Two Kentucky Bluegrass Cultivars Contrasting in Heat Tolerance

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.139.5.587 ◽

2014 ◽

Vol 139 (5) ◽

pp. 587-596 ◽

Cited By ~ 9

Author(s):

Feifei Li ◽

Da Zhan ◽

Lixin Xu ◽

Liebao Han ◽

Xunzhong Zhang

Keyword(s):

Heat Stress ◽

Antioxidant Enzyme ◽

Heat Tolerance ◽

Poa Pratensis ◽

Perennial Grass ◽

Kentucky Bluegrass ◽

Grass Species ◽

Limiting Factor ◽

Antioxidant Enzyme Activities ◽

Aba Content

Heat stress is a major limiting factor for growth of cool-season perennial grass species, and mechanisms of heat tolerance have not been well understood. This study was designed to investigate antioxidant enzyme and hormone metabolism responses to heat stress in two kentucky bluegrass (Poa pratensis L.) cultivars contrasting in heat tolerance. The plants were subjected to 20/20 °C [day/night (control)] or 38/30 °C [day/night (heat stress)] for 28 days in growth chambers. Heat stress increased leaf electrolyte leakage (EL) and malondialdehyde (MDA) with heat-tolerant cultivar EverGlade exhibiting lower levels of EL and MDA relative to heat-sensitive cultivar Kenblue under heat stress. Superoxide dismutase (SOD) and catalase (CAT) activity increased and then declined during 28 days of heat stress. Peroxidase (POD) and ascorbate peroxidase (APX) activity declined and then increased during heat stress. ‘EverGlade’ had greater activities of SOD, CAT, POD, and APX relative to ‘Kenblue’ under heat stress. In addition, ‘EverGlade’ had two additional SOD isozymes and three additional POD isozymes relative to ‘Kenblue’ under heat stress. Leaf abscisic acid (ABA) increased in response to heat stress. Leaf indole-3-acetic acid (IAA) increased and then declined during heat stress. ‘OverGlade’ had higher ABA and IAA content relative to ‘Kenblue’. At the end of heat stress, leaf IAA and ABA content were 27.8% and 73% higher in ‘EverGlade’ relative to ‘Kenblue’, respectively. The results indicated that antioxidant enzymes and the hormones (ABA and IAA) were associated with kentucky bluegrass heat tolerance. Selection and use of cultivars with higher IAA and ABA content and greater antioxidant enzyme activities may improve kentucky bluegrass growth and quality under heat stress.

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Month of Seeding Effect on Low-Input Establishment of Cool- and Warm-Season Turfgrasses in Continental Transition Zone

Atlas Journal of Biology ◽

10.5147/ajb.v2i3.27 ◽

2017 ◽

Vol 2 (3) ◽

pp. 162-170

Author(s):

Kenneth Lynn Diesburg ◽

Ronald F. Krausz

Keyword(s):

Transition Zone ◽

Tall Fescue ◽

Festuca Arundinacea ◽

Seedling Survival ◽

Poa Pratensis ◽

Warm Season ◽

Kentucky Bluegrass ◽

Percent Cover ◽

Cool Season ◽

Low Input

This research was conducted to determine the degree of success, by month, in seeding establishment of tall fescue (Festuca arundinacea Schreb., Kentucky bluegrass (Poa pratensis L.), Bermudagrass (Cynodon dactylon [L.] Pers. var. dactylon), and zoysiagrass (Zoysia japonica Steud.) at two locations in the moist, Midwest, continental transition zone on a prepared seed bed without irrigation or cover. The four species were planted every month of the year starting in September 2005. Starter fertilizer and siduron were applied the same day as seeding with no subsequent management except mowing. Percent cover of living turfgrass was recorded in each of 24 months after seeding. Tall fescue (80%) and Bermudagrass (73%) provided the best percent cover over all planting dates. Kentucky bluegrass provided 65% and zoysiagrass 24% cover. The cool-season grasses performed best in the July-to-March plantings; tall fescue 88% and Kentucky bluegrass 72%. Bermudagrass (94%) established best in the January-to-April plantings, while Zoysiagrass (32%) established best in the November-to-March plantings. Germination and seedling survival after germination of all species were inhibited by limited moisture during summer. The warm-season grasses were further limited by winter kill in the August, September, and October seedings. These results emphasize the risk in spring-seeding as well as the value in dormant-seeding of both warm- and cool-season turfgrasses for low-input, nonirrigated establishment.

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Membrane Lipid Composition and Heat Tolerance in Cool-season Turfgrasses, including a Hybrid Bluegrass

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.134.5.511 ◽

2009 ◽

Vol 134 (5) ◽

pp. 511-520 ◽

Cited By ~ 28

Author(s):

Kemin Su ◽

Dale J. Bremer ◽

Richard Jeannotte ◽

Ruth Welti ◽

Celeste Yang

Keyword(s):

Heat Tolerance ◽

Molecular Species ◽

Festuca Arundinacea ◽

Membrane Lipids ◽

Poa Pratensis ◽

Kentucky Bluegrass ◽

Membrane Lipid ◽

Cool Season ◽

Lipid Molecular Species ◽

Heat Tolerant

Cool-season turfgrasses may experience heat stress during summer. Hybrid bluegrasses (HBGs), crosses between kentucky bluegrass [KBG (Poa pratensis L.)] and native texas bluegrass (Poa arachnifera Torr.), have improved heat tolerance but the mechanisms of heat tolerance are poorly understood. Our objectives were to quantitatively profile membrane lipid molecular species in three cool-season turfgrasses exposed to optimal (22/15 °C, 14/10 h light/dark) and supra-optimal temperatures (35/25 °C and 40/30 °C, 14/10 h light/dark). Grasses included a low heat-tolerant tall fescue [TF (Festuca arundinacea Schreb. ‘Dynasty’)], a mid-heat–tolerant KBG (‘Apollo’), and a heat-tolerant HBG (‘Thermal Blue’). At high temperature, glycolipid digalactosyldiacylglycerol (DGDG) in HBG was 12% and 16% greater than in KBG and TF, respectively, and the ratio DGDG to monogalactosyldiacylglycerol was 19% and 44% greater in HBG than in KBG and TF, respectively. Greater heat tolerance in HBG and KBG was associated with higher contents of phosphatidylethanolamine and phosphatidylglycerol, and with reduced overall unsaturation compared with TF. Overall, 20 lipid molecular species were present in greater amounts and another 20 species in lesser amounts in HBG and KBG than in TF. Results suggest 40 membrane lipid molecules are potential biomarkers for heat tolerance and that compositional changes in membrane lipids in response to heat contribute to differences in heat tolerance among cool-season grasses.

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Heat Tolerance of Kentucky Bluegrass as Affected by Trinexapac-ethyl

HortScience ◽

10.21273/hortsci.36.2.365 ◽

2001 ◽

Vol 36 (2) ◽

pp. 365-367 ◽

Cited By ~ 8

Author(s):

Neil L. Heckman ◽

Garald L. Horst ◽

Roch E. Gaussoin ◽

Linda J. Young

Keyword(s):

Heat Stress ◽

Heat Tolerance ◽

Vapor Pressure Deficit ◽

Poa Pratensis ◽

Acid Methyl Ester ◽

Kentucky Bluegrass ◽

Single Application ◽

Heat Accumulation ◽

Lethal Temperatures ◽

Acid Methyl

Heat accumulation during storage of sod may reach lethal temperatures within 4 days, decreasing sod quality. Treatment with trinexapac-ethyl reduces heat accumulation during sod storage. However, heat tolerance of grasses treated with trinexapacethyl has not been documented. Our objectives were to: 1) determine the lethal temperatures for Kentucky bluegrass (Poa pratensis L.); and 2) identify the effect of a single application of trinexapac-ethyl on heat tolerance. Experimental design was a randomized complete block with three replications and a two (trinexapac-ethyl vs. control) × two (cultivars) factorial arrangement of treatments. Ten days after chemical treatment, Kentucky bluegrass sprigs were exposed to heat stress for 4 days in a temperature gradient block under low vapor pressure deficit. Treatment with trinexapac-ethyl at 0.23 kg·ha-1 reduced heat tolerance. Temperature needed to kill 50% of the population was 35.5 °C for treated vs. 36.1 °C for nontreated grass. Trinexapac-ethyl is in the same chemical family as the cyclohexanedione herbicides that interfere with lipid syntheses in grasses. This may be a reason for the slight decrease in heat tolerance. The practical value of trinexapac-ethyl treatment in reducing heat accumulation during storage of sod may be partially negated by a decrease in heat tolerance. Chemical name used: [(4-cyclopropyl-α-hydroxy-methylene)-3,5-dioxocyclohexanecarboxylic acid methyl ester] (trinexapac-ethyl).

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Turf Species Affects Establishment and Growth of Redbud and Pecan

HortScience ◽

10.21273/hortsci.42.2.267 ◽

2007 ◽

Vol 42 (2) ◽

pp. 267-271 ◽

Cited By ~ 3

Author(s):

Jason J. Griffin ◽

William R. Reid ◽

Dale J. Bremer

Keyword(s):

Festuca Arundinacea ◽

Resource Competition ◽

Cynodon Dactylon ◽

Poa Pratensis ◽

Warm Season ◽

Net Photosynthesis ◽

Kentucky Bluegrass ◽

Nutrient Concentrations ◽

Root Weight ◽

Cool Season

Establishment and growth of eastern redbud (Cercis canadensis L.) and pecan [Carya illinoinensis (Wangenh.) K. Koch] were studied where soil surfaces were either covered with each of three common turfgrass species or maintained free of vegetation by the use of an herbicide or an organic mulch layer. Turf species included two cool-season grasses, tall fescue (Festuca arundinacea Schreb.) and Kentucky bluegrass (Poa pratensis L.), and the warm-season bermudagrass [Cynodon dactylon (L.) Pers.]. After two growing seasons, tree caliper of both species was 100% greater in turf-free plots compared with trees in the cool-season grass plots. Root weight of pecans increased nearly 200% when turf was eliminated, and redbud root weight increased nearly 300%. Top weight of redbuds increased 300% and pecans increased 200% when turf was eliminated. Total leaf weight of both species was 300% greater in the turf-free plots, and leaf area increased 200% in both species. Net photosynthesis of redbud trees tended to be higher in the plots without turfgrass, and cool-season grasses inhibited photosynthesis to a greater extent than the warm-season grass. Foliar tissue analysis revealed that nitrogen (N) and potassium (K) were the only elements that increased in concentration when turf was eliminated. However, nutrient concentrations in all treatments were within recommended standard ranges. The results suggest that landscape tree establishment and growth are greatly inhibited by the presence of cool-season turfgrasses and that the inhibition may be more complicated than resource competition.

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

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.140.5.459 ◽

2015 ◽

Vol 140 (5) ◽

pp. 459-465 ◽

Cited By ~ 2

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.

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Chitosan (CTS) Alleviates Heat-Induced Leaf Senescence in Creeping Bentgrass by Regulating Chlorophyll Metabolism, Antioxidant Defense, and the Heat Shock Pathway

Molecules ◽

10.3390/molecules26175337 ◽

2021 ◽

Vol 26 (17) ◽

pp. 5337

Author(s):

Cheng Huang ◽

Yulong Tian ◽

Bingbing Zhang ◽

Muhammad Jawad Hassan ◽

Zhou Li ◽

...

Keyword(s):

Heat Stress ◽

Heat Shock ◽

Leaf Senescence ◽

Heat Tolerance ◽

Antioxidant Defense ◽

Creeping Bentgrass ◽

Grass Species ◽

Antioxidant Enzyme Activities ◽

Ros Scavenging ◽

Chlorophyll Metabolism

Chitosan (CTS) is a deacetylated derivative of chitin that is involved in adaptive response to abiotic stresses. However, the regulatory role of CTS in heat tolerance is still not fully understood in plants, especially in grass species. The aim of this study was to investigate whether the CTS could reduce heat-induced senescence and damage to creeping bentgrass associated with alterations in antioxidant defense, chlorophyll (Chl) metabolism, and the heat shock pathway. Plants were pretreated exogenously with or without CTS (0.1 g L−1) before being exposed to normal (23/18 °C) or high-temperature (38/33 °C) conditions for 15 days. Heat stress induced detrimental effects, including declines in leaf relative water content and photochemical efficiency, but significantly increased reactive oxygen species (ROS) accumulation, membrane lipid peroxidation, and Chl loss in leaves. The exogenous application of CTS significantly alleviated heat-induced damage in creeping bentgrass leaves by ameliorating water balance, ROS scavenging, the maintenance of Chl metabolism, and photosynthesis. Compared to untreated plants under heat stress, CTS-treated creeping bentgrass exhibited a significantly higher transcription level of genes involved in Chl biosynthesis (AsPBGD and AsCHLH), as well as a lower expression level of Chl degradation-related gene (AsPPH) and senescence-associated genes (AsSAG12, AsSAG39, Asl20, and Ash36), thus reducing leaf senescence and enhancing photosynthetic performance under heat stress. In addition, the foliar application of CTS significantly improved antioxidant enzyme activities (SOD, CAT, POD, and APX), thereby effectively reducing heat-induced oxidative damage. Furthermore, heat tolerance regulated by the CTS in creeping bentgrass was also associated with the heat shock pathway, since AsHSFA-6a and AsHSP82 were significantly up-regulated by the CTS during heat stress. The potential mechanisms of CTS-regulated thermotolerance associated with other metabolic pathways still need to be further studied in grass species.

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