Differences in Freeze Tolerance of Zoysiagrasses: II. Carbohydrate and Proline Accumulation

Abstract

Cold hardiness among zoysiagrass (Zoysia spp.) genotypes varies, but the physiological basis for cold hardiness is not completely understood. The objective of this study was to determine the relationship of carbohydrate (starch, total soluble sugars, total reducing sugars, sucrose, glucose, and raffinose family oligosaccharides) and proline concentrations with the cold acclimation of zoysiagrass and the lethal temperature killing 50% of the plants (LT50). Thirteen genotypes of zoysiagrass were selected with contrasting levels of winter hardiness. Plants were grown for 4 wk of 8/2°C day/night cycles and a 10‐h photoperiod of 300 μmol m−2 s−1 to induce cold acclimation. Rhizomes and stolons were sampled from nonacclimated and cold‐acclimated plants and used for carbohydrate and proline analysis. Concentrations of soluble sugars and proline increased during cold acclimation, while starch concentrations decreased. Starch, sugar/starch ratio, glucose, total reducing sugars, and proline in cold‐acclimated plants were correlated (r = 0.61, −0.67, −0.73, −0.62, and −0.62, respectively) with LT50 These correlations indicate that higher concentrations of total reducing sugars, glucose, and proline are positively associated with zoysiagrass freeze tolerance, whereas higher concentrations of starch appeared detrimental to freeze tolerance.

Identifying Differentially Expressed Genes Associated with Tolerance against Low Temperature Stress in Brassica napus through Transcriptome Analysis

“…In this study, the concentration of proline and soluble sugar were increased in shoots under low temperature, and the increase in resistant variety was significantly higher than sensitive variety. Similar results were also found in previous researches (Kushad and Yelenosky, 1987;Patton et al, 2007;Burbulis et al, 2011;Li et al, 2013). Carbohydrate and protein metabolism is the foundation for the rapeseed seedling establishment (Patton et al, 2007;Lutz, 2010).…”

“…Similar results were also found in previous researches (Kushad and Yelenosky, 1987;Patton et al, 2007;Burbulis et al, 2011;Li et al, 2013). Carbohydrate and protein metabolism is the foundation for the rapeseed seedling establishment (Patton et al, 2007;Lutz, 2010). Transcriptome results revealed that beta-amylase and betaglucosidase genes expression were up-regulated in low temperature stress to increase the sugar content.…”

“…An analysis of morphological traits under low temperature conditions indicated that seedling height, and shoot dry weights decreased as temperature decreased in sorghum (Yu et al, 2004). Higher concentrations of soluble sugars, glucose and proline were positively associated with low temperature stress, which acted as osmotic substances to preserve protein structure and function (Patton et al, 2007;Burbulis et al, 2011;Trischuk et al, 2014;Farooq et al, 2016). Low temperature stress induced the accumulation of reactive oxygen species (ROS) such as superoxide, hydrogen peroxide, and hydroxyl radicals (Suzuki and Mittler, 2006;Farooq et al, 2009).…”

Proline Accumulates in Response to Higher Temperatures during Dehardening in Peach Shoot Tissues

“…Pro content was determined using the ninhydrin method with slight modification (Patton et al, 2007). Seven 5 cm-long shoot segments collected from each cultivar were immediately frozen in liquid N 2 , ground using a mixer mill with grinding jars and balls (TissueLyser II; Qiagen, Dusseldorf, Germany) for 1 min, and stored as powder at −80°C until use.…”

Detection of Sugar Accumulation and Expression Levels of Correlative Key Enzymes in Winter Wheat (Triticum aestivum) at Low Temperatures

“…They are usually accumulated at low temperatures, leading to improvement in plants' tolerance to cold. [3][4][5][6] Recent studies have also shown that sugar signaling is closely associated with hormone signaling, the control of growth and development, and responses to stress in plants. 7,8) Large numbers of genes are involved in sugar accumulation and can be regulated in complex ways.…”