Protein Changes during Heat Stress in Three Kentucky Bluegrass Cultivars Differing in Heat Tolerance

Abstract

Supraoptimal temperature limits growth and metabolic activities of cool‐season turfgrasses. Understanding genetic variations and mechanisms in turfgrass heat tolerance would facilitate breeding and management programs to improve turf quality under summer stress. The objective of this study was to investigate protein changes associated with heat tolerance in three Kentucky bluegrass (Poa pratensis L.) cultivars. Plants of ‘Brilliant’, ‘Midnight’, and ‘Eagleton’ were subjected to 20°C (day/night, control) or 40°C (day/night, heat stress) in growth chambers. Eagleton maintained higher chlorophyll content and fewer yellow leaves than Brilliant, while Midnight was intermediate for both parameters at 28 d of heat stress. The content of cytoplasmic and membrane proteins declined during heat stress, to a greater extent in Brilliant than in Midnight and Eagleton. The content of both types of proteins in Brilliant were significantly lower than in Eagleton, but not different from that in Midnight. The sodium dodecyl sulfate‐polyacrylamide gel electrophoresis (SDS‐PAGE) analysis revealed that Brilliant exhibited more severe protein degradation than other two cultivars. Heat stress induced expression of several heat shock proteins (HSPs) in the cytoplasm (64, 78, and 85 kDa) and membranes (39, 45, and 66 kDa) in all three cultivars, but the induction occurred 7 to 14 d earlier in Eagleton or Midnight than in Brilliant. An additional membrane protein of 68 kDa was induced in Midnight under heat stress. The results suggested that better heat tolerance in the Kentucky bluegrass was associated with induction of HSPs during the early phase of heat stress and maintenance of higher protein content and less severe protein degradation during prolonged periods of heat stress.

Comparative response of maize and rice genotypes to heat stress: status of oxidative stress and antioxidants

“…Our observations regarding increase in APX match with the findings in heat-stressed plants of mulberry (Chaitanya et al 2002) and wheat (Sairam et al 2000) while the inhibition in its activity at higher temperature is in agreement with the observations on Arabidopsis (Panchuk Irina et al 2002). Previously, it has been reported that the heat-tolerant genotype of Kentucky grass (Poa pratensis) had significantly higher APX activity than its sensitive genotype (He and Huang 2007). In our studies, the maize genotypes possessed appreciably higher APX activity at both these temperature regimes suggesting their higher capacity to neutralize hydrogen peroxide and also corroborating their tolerance to heat stress.…”

“…The heat-tolerant genotypes of wheat possessed higher expression of catalase (Balla et al 2009) compared to the sensitive ones. On the other hand, He and Huang (2007) observed greater CAT activity in heat-sensitive genotype of Kentucky grass (Poa pratensis). Our studies indicated that maize having higher CAT activity possessed better ability to remove hydrogen peroxide than rice genotypes.…”

“…Thus, Almeselmani et al (2009) reported greater activity of SOD in heat-tolerant genotypes of wheat subjected to heat stress (35/25°C). Similarly, He and Huang (2007) reported that the heat-tolerant genotype of Kentucky grass (Poa pratensis) had significantly higher SOD activity than its sensitive genotype.…”

The influence of low pH on in vitro growth and biochemical parameters of Plantago almogravensis and P. algarbiensis

“…Soluble protein content is an important indicator of changes in metabolism, and it is known to respond to a wide variety of stresses (Singh and Tewari 2003). A higher content of soluble protein has been reported in several plant species under adverse growth conditions (Ashraf and Harris 2004;He and Huang 2007).…”

Characterization, Development, and Management of Organic Matter in Turfgrass Systems

“…Plant organic materials primarily comprise the constituents of the cell walls and cytoplasm. These include structural carbohydrates, such as cellulose, hemicellulose, and lignin; nonstructural carbohydrates, such as sucrose, fructose, and starch; proteins and other nitrogenous compounds, such as enzymes and nucleic acids; lipids, including waxes, pectins, and pigments; and secondary metabolites, such as terpenoids, alkaloids, and phenylpropanoids (Shearman and Beard, 1975;Hull, 1992;Paul and Clark, 1996;Horwath, 2002Horwath, , 2007Narra et al, 2004Narra et al, , 2005Brosnan et al, 2005;Watkins et al, 2006;He and Huang, 2007;Turgeon, 2008). These vary in proportion depending on the plant type and part, the age of the material, and the extent of decay (Shearman and Beard, 1975;Martens, 2000;Trenholm et al, 2000;Johnson et al, 2007).…”