Changes in Carbohydrate Metabolism in Two Kentucky Bluegrass Cultivars during Drought Stress and Recovery

Carbohydrate metabolism is important for plant adaptation to drought stress. The objective of this study was to examine major forms of carbohydrates associated with superior drought tolerance and post-drought recovery in kentucky bluegrass (Poa pratensis) by comparing responses of different forms of carbohydrates with drought stress and re-watering in two cultivars contrasting in drought tolerance. Plants of drought-tolerant ‘Midnight’ and drought-sensitive ‘Brilliant’ were maintained well watered or subjected to drought stress for 10 days by withholding irrigation, and drought-stressed plants were re-watered for 3 days. Physiological analysis (turf quality, relative water content, and electrolyte leakage) confirmed the genetic variability of the two cultivars in drought tolerance. The two cultivars exhibited differential responses to drought stress and re-watering for the content of water-soluble sugars (sucrose, fructose, and glucose) and storage carbohydrates (starch and fructan), and ‘Midnight’ maintained higher sucrose content at 10 days of drought stress and more fructan at 3 days of re-watering. The greater accumulation of sucrose in ‘Midnight’ under drought stress corresponded with higher activities of two sucrose-synthesizing enzymes (sucrose phosphate synthase and sucrose synthase) but was not related to the sucrose-degrading enzyme activity (acid invertase). These results suggested that increased sucrose accumulation resulting from the maintenance of active sucrose synthesis could be associated with superior turf performance during drought stress, whereas increased fructan accumulation could contribute to rapid re-growth and post-drought recovery on re-watering in kentucky bluegrass.

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

The Scientific World JOURNAL ◽

10.1155/2014/368694 ◽

2014 ◽

Vol 2014 ◽

pp. 1-10 ◽

Cited By ~ 62

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.

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Antioxidant Enzyme Activities and Gene Expression Patterns in Leaves of Kentucky Bluegrass in Response to Drought and Post-drought Recovery

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.136.4.247 ◽

2011 ◽

Vol 136 (4) ◽

pp. 247-255 ◽

Cited By ~ 49

Author(s):

Lixin Xu ◽

Liebao Han ◽

Bingru Huang

Keyword(s):

Gene Expression ◽

Drought Stress ◽

Antioxidant Enzyme ◽

Water Deficit ◽

Poa Pratensis ◽

Kentucky Bluegrass ◽

Grass Species ◽

Antioxidant Enzyme Activities ◽

Guaiacol Peroxidase ◽

Drought Recovery

The objectives of this study were to examine antioxidant enzyme responses to drought stress and rewatering at both enzymatic activity and transcript levels and to determine the major antioxidant processes associated with drought tolerance and post-drought recovery for a perennial grass species, kentucky bluegrass (Poa pratensis). Antioxidant enzyme responses to drought and rewatering in a drought-tolerant cultivar (Midnight) and a drought-sensitive cultivar (Brilliant) were compared in a growth chamber. Plants were exposed to 22 days of drought stress for ‘Midnight’ and 18 days for ‘Brilliant’ before rewatering to allow the leaf relative water content (RWC) of both cultivars to drop to the same level. ‘Midnight’ exhibited higher photochemical efficiency (Fv/Fm) and lower electrolyte leakage compared with ‘Brilliant’ when at the same water deficit status (26% to 28% RWC). After 6 days of rewatering, all physiological parameters returned to the control level for ‘Midnight’, but only Fv/Fm fully recovered for ‘Brilliant’. The transcript level of cytosolic copper/zinc superoxide dismutase (cyt Cu/Zn SOD) and ascorbate peroxidase (APX) was significantly higher in ‘Midnight’ than in ‘Brilliant’ when exposed to the same level of water deficit (26% to 28% RWC), suggesting that SOD and APX could be involved in scavenging oxidative stress-induced reactive oxygen species in kentucky bluegrass through changes in the level of gene expression. Significantly higher activities of APX, monodehydroascorbate reductase, glutathione reductase, and dehydroascorbate reductase as well as lower lipid peroxidation levels were observed in ‘Midnight’ versus ‘Brilliant’ when exposed to drought. However, the activities of SOD, catalase (CAT), and guaiacol peroxidase (POD) did not differ between the two cultivars. After 6 days of rewatering, ‘Midnight’ displayed significantly higher activity levels of CAT, POD, and APX compared with ‘Brilliant’. The enzyme activity results indicate that enzymes involved in the ascorbate–glutathine cycle may play important roles in antioxidant protection to drought damage, whereas CAT, POD, and APX could be associated with better post-drought recovery in kentucky bluegrass.

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Effects of Biosolids on Root Growth and Nitrogen Metabolism in Kentucky Bluegrass under Drought Stress

HortScience ◽

10.21273/hortsci.49.9.1205 ◽

2014 ◽

Vol 49 (9) ◽

pp. 1205-1211 ◽

Cited By ~ 2

Author(s):

Zhihui Chang ◽

Laiqiang Zhuo ◽

Fangfang Yu ◽

Xunzhong Zhang

Keyword(s):

Drought Stress ◽

Drought Tolerance ◽

Root Growth ◽

Poa Pratensis ◽

Amino Acid Content ◽

Kentucky Bluegrass ◽

Biologically Active ◽

Hormone Metabolism ◽

Available N ◽

Container Capacity

Biosolids are valued as a source of plant nutrients, soil organic matter, and biologically active substances. This greenhouse study was designed to examine if application of biosolids can improve plant drought tolerance by affecting nitrogen (N) and hormone metabolism as well as root growth in kentucky bluegrass (Poa pratensis L.; KBG). The three treatments, which provided N rates equivalent to 75 mg plant-available N/kg soil, included: 1) biosolids at 1× agronomic (Ag) N rate (75 mg N/kg soil completely provided with biosolids); 2) biosolids at 0.5× Ag N rate (37.5 mg N/kg soil provided with biosolids and 37.5 mg N/kg soil provided with NH4NO3); and 3) control (75 mg N/kg soil completely provided with NH4NO3). The treated KBG was grown under either well-watered (90% container capacity) or drought stress (≈25% container capacity) conditions. Biosolids application improved turf quality and delayed leaf wilting under drought stress. The grass treated with biosolids at 1× N rate had higher leaf proline and amino acid content and greater nitrate reductase activity than the control under drought stress. Biosolids treatments also increased leaf and soil indole-3-acetic acid (IAA) content. Moreover, biosolids at 1× N rate increased root length density by 23% compared with the control under drought stress. The results of this study suggest that biosolids may enhance plant drought tolerance by improving N and hormone metabolism and root growth in KBG.

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Abscisic Acid Accumulation in Relation to Drought Tolerance in Kentucky Bluegrass

HortScience ◽

10.21273/hortsci.39.5.1133 ◽

2004 ◽

Vol 39 (5) ◽

pp. 1133-1137 ◽

Cited By ~ 14

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.

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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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Growth and Physiological Traits Associated with Drought Survival and Post-drought Recovery in Perennial Turfgrass Species

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.135.2.125 ◽

2010 ◽

Vol 135 (2) ◽

pp. 125-133 ◽

Cited By ~ 35

Author(s):

Qi Chai ◽

Fang Jin ◽

Emily Merewitz ◽

Bingru Huang

Keyword(s):

Cell Wall ◽

Drought Stress ◽

Osmotic Adjustment ◽

Perennial Grass ◽

Kentucky Bluegrass ◽

Physiological Traits ◽

Grass Species ◽

Cell Wall Elasticity ◽

Drought Recovery ◽

Drought Survival

The objective of this study was to determine physiological traits for drought survival and post-drought recovery upon re-watering in two C3 perennial grass species, kentucky bluegrass [KBG (Poa pratensis)] and perennial ryegrass [PRG (Lolium perenne)]. Plants were maintained well watered or exposed to drought stress by withholding irrigation and were then re-watered in a growth chamber. KBG had significantly higher grass quality and leaf photochemical efficiency, and lower electrolyte leakage than PRG during 20 days of drought. After 7 days of re-watering, drought-damaged leaves were rehydrated to the control level in KBG, but could not fully recover in PRG. KBG produced a greater number of new roots, while PRG had more rapid elongation of new roots after 16 days of re-watering. Superior drought tolerance in KBG was associated with osmotic adjustment, higher cell wall elasticity, and lower relative water content at zero turgor. Osmotic adjustment, cell wall elasticity, and cell membrane stability could play important roles in leaf desiccation tolerance and drought survival in perennial grass species. In addition, post-drought recovery of leaf hydration level and physiological activity could be associated with the accumulation of carbohydrates in leaves and rhizomes during drought stress and new root production after re-watering.

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Overexpression of a Voltage-Dependent Anion-Selective Channel (VDAC) Protein-Encoding Gene, MsVDAC, from Medicago sativa Confers Cold and Drought Tolerance to Transgenic Tobacco

Genes ◽

10.3390/genes12111706 ◽

2021 ◽

Vol 12 (11) ◽

pp. 1706

Author(s):

Mei Yang ◽

Xinhang Duan ◽

Zhaoyu Wang ◽

Hang Yin ◽

Junrui Zang ◽

...

Keyword(s):

Drought Stress ◽

Drought Tolerance ◽

Cold Stress ◽

Medicago Sativa ◽

Transgenic Tobacco ◽

Soluble Sugars ◽

Ros Scavenging ◽

Osmotic Homeostasis ◽

Voltage Dependent ◽

Stress Responsive Genes

Voltage-dependent anion channels (VDACs) are highly conserved proteins that are involved in the translocation of tRNA and play a key role in modulating plant senescence and multiple pathways. However, the functions of VDACs in plants are still poorly understood. Here, a novel VDAC gene was isolated and identified from alfalfa (Medicago sativa L.). MsVDAC localized to the mitochondria, and its expression was highest in alfalfa roots and was induced in response to cold, drought and salt treatment. Overexpression of MsVDAC in tobacco significantly increased MDA, GSH, soluble sugars, soluble protein and proline contents under cold and drought stress. However, the activities of SOD and POD decreased in transgenic tobacco under cold stress, while the O2− content increased. Stress-responsive genes including LTP1, ERD10B and Hxk3 were upregulated in the transgenic plants under cold and drought stress. However, GAPC, CBL1, BI-1, Cu/ZnSOD and MnSOD were upregulated only in the transgenic tobacco plants under cold stress, and GAPC, CBL1, and BI-1 were downregulated under drought stress. These results suggest that MsVDAC provides cold tolerance by regulating ROS scavenging, osmotic homeostasis and stress-responsive gene expression in plants, but the improved drought tolerance via MsVDAC may be mainly due to osmotic homeostasis and stress-responsive genes.

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Effects of Abscisic Acid on Drought Responses of Kentucky Bluegrass

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.128.1.0036 ◽

2003 ◽

Vol 128 (1) ◽

pp. 36-41 ◽

Cited By ~ 47

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.

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(140) Salt Tolerance Assessment of Kentucky Bluegrass Cultivars Selected for Drought Tolerance

HortScience ◽

10.21273/hortsci.41.4.1057c ◽

2006 ◽

Vol 41 (4) ◽

pp. 1057C-1057 ◽

Cited By ~ 1

Author(s):

Catherine M. Grieve ◽

Stacy A. Bonos ◽

James A. Poss

Keyword(s):

Salt Tolerance ◽

Drought Tolerance ◽

Growth Rates ◽

Poa Pratensis ◽

Block Design ◽

Kentucky Bluegrass ◽

Saline Control ◽

Drought Tolerant ◽

Area Expansion ◽

Poa Arachnifera

Six selections of Kentucky bluegrass (Poa pratensis L.) cultivars, selected based on their drought tolerance under field and growth chamber conditions in New Brunswick, N.J., were evaluated for salt tolerance based on yield and growth rates at eight soil water salinities [2 (control), 6, 8, 10, 12, 14, 18, and 22 dSm-1] from Apr. to Sept. 2005 in Riverside, Calif. Cultivars Baron and Brilliant were selected as drought sensitive and `Cabernet', `Eagleton', and `Midnight' were selected as drought tolerant. A Texas × Kentucky bluegrass (Poa arachnifera × Poa pratensis) hybrid selection (identified as A01-856) developed for improved drought and heat tolerance was also included. Vegetative clones were established in a randomized complete-block design with three replications, each containing 11 clones. Cumulative biomass and clone diameters were measured over time to evaluate relative yields and growth rates for the six cultivar selections. Based upon maximum absolute biomass production as a function of increasing EC, the order of production was `Baron' > `Brilliant' > `Eagleton' > `Cabernet' ≥ `Midnight' > A01-856. Yield relative to the non-saline control (2 dSm-1) for each cultivar was similar, except that the differences between cultivars were less pronounced, and `Baron' slightly outperformed `Brilliant'. Clone area expansion rates were analyzed with a phasic growth model and beta, the intrinsic growth rate of the exponential phase parameter, significantly varied with salinity. Ranking of cultivars, based on expansion rates, was similar to that based on cumulative biomass. Salinity tolerance in this experiment did not appear to be related to the observed ranking for drought tolerance.

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A Vacuolar Invertase CsVI2 Regulates Sucrose Metabolism and Increases Drought Tolerance in Cucumis sativus L.

International Journal of Molecular Sciences ◽

10.3390/ijms23010176 ◽

2021 ◽

Vol 23 (1) ◽

pp. 176

Author(s):

Lin Chen ◽

Fenghua Zheng ◽

Zili Feng ◽

Yue Li ◽

Muxuan Ma ◽

...

Keyword(s):

Drought Stress ◽

Drought Tolerance ◽

Cucumis Sativus ◽

Sucrose Synthase ◽

Sucrose Phosphate Synthase ◽

Invertase Activity ◽

Cucumis Sativus L ◽

Vacuolar Invertase ◽

Cucumber Seedlings ◽

Sucrose Phosphate

Vacuolar invertase (VI) can irreversibly degrade sucrose into glucose and fructose and involve in plants abiotic-stress-tolerance. Cucumber (Cucumis sativus L.) is susceptible to drought stress, especially during the seedling stage. To date, the involvement of VI in drought tolerance in cucumber seedlings is in urgent need of exploration. In the present study, a cucumber vacuolar invertase gene, CsVI2, was isolated and functionally characterized. The results showed that (1) CsVI2 showed vacuolar invertase activity both in vivo and in vitro; (2) the transcript level of CsVI2, along with VI activity, was significantly induced by drought stress. Moreover, the expression of sucrose synthase 3 (CsSUS3) was increased and that of sucrose phosphate synthase 1 (CsSPS1) was decreased after exposure to drought stress, which was followed by an increase in sucrose synthase activity and a decrease in sucrose phosphate synthase activity; (3) CsVI2-overexpressing transformed cucumber seedlings showed enhanced vacuolar invertase activity and drought tolerance and 4) protein–protein interaction modelling indicated that a cucumber invertase inhibitor, CsINVINH3, can interact with CsVI2. In summary, the results indicate that CsVI2 as an invertase can regulate sucrose metabolism and enhance drought stress in cucumber seedlings.

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