Lipid Composition of Three Bermudagrasses in Response to Chilling Stress

Abstract

<jats:p>Cell and plastid membranes play a critical role in plant response to chilling stress. Fall color retention (chilling tolerance) of bermudagrass (<jats:italic>Cynodon</jats:italic> sp.) is known to vary with cultivar and management practices. A growth chamber study was conducted to characterize the lipid composition of three bermudagrasses in response to chilling stress. The grasses selected were ‘Tahoma 31’ (chilling-sensitive) and ‘Tifway’ (chilling-tolerant) interspecific hybrid bermudagrass (<jats:italic>C. dactylon</jats:italic> × <jats:italic>C. transvaalensis</jats:italic>) and ‘Celebration’ common bermudagrass (<jats:italic>C. dactylon</jats:italic>), which served as an internal standard. Plants were subjected to simulated fall conditions defined as an 8/2 °C (day/night) temperature regime with 10-hour photoperiod and evaluated for chilling response for 42 days before allowing plants to enter an apparent dormancy. Plant leaves were sampled for lipidomics analysis at 0, 14, and 42 days of chilling treatment (DOT) and again after 40 days of recovery from dormancy (during which temperatures were adjusted to mimic average spring conditions for Oklahoma). ‘Tifway’ demonstrated the lowest electrolyte leakage (EL) and visual discoloration at 42 DOT, while ‘Tahoma 31’ had the greatest EL and discoloration on the same date, and ‘Celebration’ was intermediate of the two. Prolonged exposure to chilling stress generally increased digalactosyldiacylglycerol and phosphatidylcholine (PC) content and decreased monogalactosyldiacylglycerol (MGDG) content, with ‘Tahoma 31’ showing the greatest increase in PC and decrease in MGDG. The double bond index, an indicator of fatty acid unsaturation, was greatest in ‘Tifway’ at 42 DOT. Each cultivar increased in fatty acid unsaturation, with Tifway demonstrating the greatest increase in MGDG unsaturation. Multivariate discriminant analysis identified six individual lipid species that contributed most to the cultivar response to chilling. These findings suggest unsaturation level of plastid lipids, particularly MGDG, is important for chilling tolerance and therefore fall color retention of bermudagrass. Furthermore, this study provides evidence that chilling tolerance can be negatively associated with freezing tolerance in bermudagrass.</jats:p>

Genetic variability and QTL mapping of winter survivability and leaf firing in African bermudagrass

“…In the African bermudagrass S 1 population evaluated in the present study, the moderate SG heritability was due to the substantial genotype × year variance and large residual variance, suggesting both genetic and environmental factors influenced phenotypic expression. Bermudagrass winter survivability is affected by cold acclimation (Fontanier et al., 2020), freeze tolerance (Anderson et al., 1993; Anderson & Taliaferro, 2002; Gopinath et al., 2021), and deacclimation (Chalmers & Schmidt, 1979). Therefore, frequent freeze events and associated variabilities during cold acclimation and deacclimation stages may influence winter survival year by year.…”

“…Therefore, breeding efforts have targeted the development of turf‐type bermudagrass cultivars with improved winter survivability (Anderson & Taliaferro, 2002). Winter survivability of bermudagrass requires survival of nodes within rhizomes or stolons through low winter temperatures followed by normal growth in the subsequent spring (Fontanier et al., 2020). Controlled environment experiments have been used to estimate the lethal freezing temperature to reach 50% mortality (LT50) of selected turf‐type bermudagrasses (Anderson et al., 1993; Anderson & Taliaferro, 2002; Anderson et al., 2003; Gopinath et al., 2021).…”

Multispecies genotype × environment interaction for turfgrass quality in five turfgrass breeding programs in the southeastern United States

“…In addition, the genetic correlation of the same trait under different environments (Type B) is useful to quantify the genotype × environment (GE) interaction, and its magnitude ranges from 0 to 1, indicating high and low GE interaction, respectively (Yamada, 1962). The warm‐season turfgrass breeding programs listed above have focused on improvement of several traits such as turfgrass quality (TQ; Schwartz, Kenworthy, Engelke, Genovesi, & Quesenberry, 2009), salt and drought tolerance (Fuentealba et al., 2016; Meeks & Chandra, 2020; Schwartz et al., 2009; Schwartz et al., 2018; Xiang et al., 2017; Zhang et al., 2017), tolerance to extreme temperature (Dunne et al., 2019; Fontanier et al., 2020; Kimball, Isleib, Reynolds, Zuleta, & Milla‐Lewis, 2016; Yu et al., 2019), shade tolerance (Chhetri, Fontanier, Koh, Wu, & Moss, 2019), and biotic stress resistance (Milla‐Lewis et al., 2011; Milla‐Lewis, Youngs, Arrellano, & Cardoza, 2017). The goal of all programs is to develop regionally adapted cultivars; however, most programs are limited to more localized evaluations within their specific agroecosystems.…”

Evaluating the freeze tolerance of bermudagrass genotypes

“…The low LT 50 value of Tahoma 31 is consistent with field observations, exhibiting the least winterkill percentage of 4 and 25% in Indiana and Kentucky, respectively, with superior post-dormancy regrowth (NTEP, 2014). Tahoma 31 quickly recovered and reached 75% green coverage within 22 d after chilling stress was removed (Fontanier et al, 2020), indicating high recovery potential after freeze temperatures. The LT 50 values of Tahoma 31 in this study were similar to the values obtained by Gopinath et al (2021) (−7.8, −8.8, and −9.0°C).…”