Poa pratensis ECERIFERUM1 (PpCER1) is involved in wax alkane biosynthesis and plant drought tolerance

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

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.138.1.24 ◽

2013 ◽

Vol 138 (1) ◽

pp. 24-30 ◽

Cited By ~ 9

Author(s):

Zhimin Yang ◽

Lixin Xu ◽

Jingjin Yu ◽

Michelle DaCosta ◽

Bingru Huang

Keyword(s):

Drought Stress ◽

Drought Tolerance ◽

Carbohydrate Metabolism ◽

Poa Pratensis ◽

Soluble Sugars ◽

Sucrose Phosphate Synthase ◽

Kentucky Bluegrass ◽

Water Soluble ◽

Drought Recovery ◽

Physiological Analysis

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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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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Ethephon Seed Treatment Impacts on Drought Tolerance of Kentucky Bluegrass Seedlings

HortTechnology ◽

10.21273/horttech03976-18 ◽

2018 ◽

Vol 28 (3) ◽

pp. 319-326 ◽

Cited By ~ 4

Author(s):

Na Zhang ◽

Lu Han ◽

Lixin Xu ◽

Xunzhong Zhang

Keyword(s):

Lipid Peroxidation ◽

Drought Tolerance ◽

Plant Growth Regulator ◽

Seed Treatment ◽

Poa Pratensis ◽

Kentucky Bluegrass ◽

Proline Content ◽

Soluble Protein Content ◽

Drought Conditions ◽

Relative Water

Ethephon [ETH (2-chloroethylphosphonic acid, an ethylene-releasing compound)] has been used as a plant growth regulator in turfgrass management. The aim of the study was to assess the effects of ETH seed treatment on drought tolerance of kentucky bluegrass (Poa pratensis) seedlings. Seeds of two kentucky bluegrass cultivars, Midnight and Nuglade, were exposed to ETH treatment or untreated as controls. Seedlings were then exposed to two water regimes: well-watered conditions and polyethylene glycol (PEG)–induced drought conditions. ETH-treated plants exhibited better turf performance relative to the untreated control under PEG-stressed conditions illustrated by higher relative water content (RWC) and lower lipid peroxidation and lower electrolyte leakage (EL). In both cultivars, ETH treatment increased enzyme activity of ascorbate peroxidase (APX), peroxidase (POD), and catalase (CAT); proline content; and soluble protein content under PEG-induced drought conditions. The results suggest that ETH seed treatment can improve drought tolerance in kentucky bluegrass seedlings.

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Transcriptome analysis of Kentucky bluegrass subject to drought and ethephon treatment

PLoS ONE ◽

10.1371/journal.pone.0261472 ◽

2021 ◽

Vol 16 (12) ◽

pp. e0261472

Author(s):

Jiahang Zhang ◽

Yanan Gao ◽

Lixin Xu ◽

Liebao Han

Keyword(s):

Drought Tolerance ◽

Water Content ◽

Differentially Expressed Genes ◽

Transcriptome Analysis ◽

Relative Water Content ◽

Poa Pratensis ◽

Signal Transduction Pathway ◽

Kentucky Bluegrass ◽

Differentially Expressed ◽

Relative Water

Kentucky bluegrass (Poa pratensis L.) is an excellent cool-season turfgrass utilized widely in Northern China. However, turf quality of Kentucky bluegrass declines significantly due to drought. Ethephon seeds-soaking treatment has been proved to effectively improve the drought tolerance of Kentucky bluegrass seedlings. In order to investigate the effect of ethephon leaf-spraying method on drought tolerance of Kentucky bluegrass and understand the underlying mechanism, Kentucky bluegrass plants sprayed with and without ethephon are subjected to either drought or well watered treatments. The relative water content and malondialdehyde conent were measured. Meanwhile, samples were sequenced through Illumina. Results showed that ethephon could improve the drought tolerance of Kentucky bluegrass by elevating relative water content and decreasing malondialdehyde content under drought. Transcriptome analysis showed that 58.43% transcripts (254,331 out of 435,250) were detected as unigenes. A total of 9.69% (24,643 out of 254,331) unigenes were identified as differentially expressed genes in one or more of the pairwise comparisons. Differentially expressed genes due to drought stress with or without ethephon pre-treatment showed that ethephon application affected genes associated with plant hormone, signal transduction pathway and plant defense, protein degradation and stabilization, transportation and osmosis, antioxidant system and the glyoxalase pathway, cell wall and cuticular wax, fatty acid unsaturation and photosynthesis. This study provides a theoretical basis for revealing the mechanism for how ethephon regulates drought response and improves drought tolerance of 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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