Effects of Natural Zeolite to Reduce Salt Stress in Kentucky bluegrass (Poa pratensis)

Plant hormones play an important role in plant adaptation to abiotic stress, but hormonal responses of cool-season turfgrass species to salt stress are not well documented. This study was carried out to investigate the responses of hormones to salt stress and examine if salt stress-induced injury was associated with hormonal alteration in kentucky bluegrass (KBG, Poa pratensis L.). The grass was grown in a growth chamber for 6 weeks and then subjected to salt stress (170 mm NaCl) for 28 days. Salt stress caused cell membrane damage, resulting in photosynthetic rate (Pn), chlorophyll (Chl), and turf quality decline in KBG. Salt stress increased leaf abscisic acid (ABA) and ABA/cytokinin (CK) ratio; reduced trans-zeatin riboside (ZR), isopentenyl adenosine (iPA), and indole-3-acetic acid (IAA), but did not affect gibberellin A4 (GA4). On average, salt stress reduced ZR by 67.4% and IAA by 58.6%, whereas it increased ABA by 398.5%. At the end of the experiment (day 28), turf quality, Pn, and stomatal conductance (gs) were negatively correlated with ABA and ABA/CK ratio, but positively correlated with ZR, iPA, and IAA. Electrolyte leakage (EL) was positively correlated with ABA and ABA/CK and negatively correlated with ZR, iPA, IAA, and GA4. GA4 was also positively correlated with turf quality and gs. The results of this study suggest that salt stress-induced injury of the cell membrane and photosynthetic function may be associated with hormonal alteration and imbalance in KBG.

Download Full-text

Responses of Tolerant and Susceptible Kentucky Bluegrass Germplasm to Salt Stress

Journal of the American Society for Horticultural Science ◽

10.21273/jashs03755-16 ◽

2016 ◽

Vol 141 (5) ◽

pp. 449-456 ◽

Cited By ~ 3

Author(s):

B. Shaun Bushman ◽

Lijun Wang ◽

Xin Dai ◽

Alpana Joshi ◽

Joseph G. Robins ◽

...

Keyword(s):

Salt Stress ◽

Antioxidant Activities ◽

Poa Pratensis ◽

Inorganic Ions ◽

Kentucky Bluegrass ◽

Western North America ◽

Turf Quality ◽

Ionic Stress ◽

Highly Correlated ◽

Eventual Death

Much of semiarid western North America is salt affected, and using turfgrasses in salty areas can be challenging. Kentucky bluegrass (Poa pratensis L.) is relatively susceptible to salt stress, showing reduced growth, osmotic and ionic stress, and eventual death at moderate or high salt concentrations. Considerable variation exists for salt tolerance among kentucky bluegrass germplasm, but gaining consistency among studies and entries has been a challenge. In this study, two novel kentucky bluegrass accessions recently reported as salt tolerant (PI 371768 and PI 440603) and two cultivars commonly used as references (Baron and Midnight) were compared for their turf quality (TQ), stomatal conductance (gS), leaf water potential (ψLEAF), electrolyte leakage (EL), and accumulation of inorganic ions under salt stress. TQ, ψLEAF, and EL were highly correlated with each other while only moderately correlated with gS. The tolerant accessions showed higher ψLEAF and lower EL than the cultivars Midnight and Baron at increasing salt concentrations and over 28 days of treatment. The accumulation of sodium (Na) and calcium (Ca) in the leaves was highly correlated and did not vary significantly among the four entries. Genes involved in ion transport across membranes, and in antioxidant activities, were significantly induced on salt stress in the tolerant accessions relative to the susceptible. These data indicate the ability of tolerant accessions to ameliorate oxidative stress and prevent EL, and confirmed the tolerance of germplasm previously reported on while indicating mechanisms by which they tolerate the salt stress.

Download Full-text

S nutrition alleviates salt stress by maintaining the assemblage of photosynthetic organelles in Kentucky bluegrass (Poa pratensis L.)

Plant Growth Regulation ◽

10.1007/s10725-015-0140-0 ◽

2015 ◽

Vol 79 (3) ◽

pp. 367-375 ◽

Cited By ~ 3

Author(s):

Sang-Hyun Park ◽

Bok-Rye Lee ◽

Jeong-Hyun Lee ◽

Tae-Hwan Kim

Keyword(s):

Salt Stress ◽

Poa Pratensis ◽

Kentucky Bluegrass

Download Full-text

Choline-Mediated Lipid Reprogramming as a Dominant Salt Tolerance Mechanism in Grass Species Lacking Glycine Betaine

Plant and Cell Physiology ◽

10.1093/pcp/pcaa116 ◽

2020 ◽

Author(s):

Kun Zhang ◽

Weiting Lyu ◽

Yanli Gao ◽

Xiaxiang Zhang ◽

Yan Sun ◽

...

Keyword(s):

Salt Stress ◽

Salt Tolerance ◽

Glycine Betaine ◽

Metabolic Pathways ◽

Poa Pratensis ◽

Choline Chloride ◽

Photochemical Efficiency ◽

Kentucky Bluegrass ◽

Grass Species ◽

Tolerance Mechanism

Abstract Choline, as a precursor of glycine betaine (GB) and phospholipids, is known to play roles in plant tolerance to salt stress, but the downstream metabolic pathways regulated by choline conferring salt tolerance are still unclear for non-GB-accumulating species. The objectives were to examine how choline affects salt tolerance in a non-GB-accumulating grass species and to determine major metabolic pathways of choline regulating salt tolerance involving GB or lipid metabolism. Kentucky bluegrass (Poa pratensis) plants were subjected to salt stress (100 mM NaCl) with or without foliar application of choline chloride (1 mM) in a growth chamber. Choline or GB alone and the combined application increased leaf photochemical efficiency, relative water content and osmotic adjustment and reduced leaf electrolyte leakage. Choline application had no effects on the endogenous GB content and GB synthesis genes did not show responses to choline under nonstress and salt stress conditions. GB was not detected in Kentucky bluegrass leaves. Lipidomic analysis revealed an increase in the content of monogalactosyl diacylglycerol, phosphatidylcholine and phosphatidylethanolamine and a decrease in the phosphatidic acid content by choline application in plants exposed to salt stress. Choline-mediated lipid reprogramming could function as a dominant salt tolerance mechanism in non-GB-accumulating grass species.

Download Full-text