Heat Stress Injury in Relation to Membrane Lipid Peroxidation in Creeping Bentgrass

Abstract

and singlet oxygen ( 1 O 2 ) are species of active oxygen derivatives that may attack and damage macromole-Understanding physiological and biochemical factors involved in cules in living cells (Foyer et al., 1994; Halliwel, 1984; heat-stress injury would help improve heat tolerance of cool-season Scandalios, 1993Scandalios, , 1994 Smirnoff, 1993). Plants have degrasses. The objective of this study was to investigate lipid peroxidation of cell membranes in relation to heat-stress tolerance in creeping veloped enzymatic and nonenzymatic scavenging sysbentgrass (Agrostis palustris Huds.) . Two creeping bentgrass cultivars tems to quench active oxygen, and to eliminate the detridiffering in heat tolerance, L-93 (heat tolerant) and Penncross (heat mental effects of active oxygen. Superoxide dismutase sensitive) were grown under two temperature regimes: 22/16؇C (day/ (SOD) and catalase (CAT) break down (O Ϫ · 2 ) and H 2 O 2 , night) and 35/25؇C for 56 d in growth chambers. Photochemical effirespectively (Asada, 1992; Bowler et al, 1992; Elstner, ciency (Fv/Fm) and chlorophyll content of leaves; and electrolyte 1982;Scandalios, 1993Scandalios, , 1994. The ascorbate-glutathileakage (EL); content of the lipid peroxidation product, malondialdeone cycle is an alternative pathway to scavenge active hyde (MDA); and activities of antioxidant enzymes including superoxoxygen (Alscher, 1989; Creissen et al., 1994; Foyer, 1993; ide dismutase (SOD), catalase (CAT), and peroxidase (POD) in Foyer et al., 1994). When plants are subjected to adverse leaves and roots were determined biweekly during heat stress. Leaf Fv/Fm ratio and chlorophyll content decreased, whereas EL and MDA conditions such as high or low temperature, drought, contents of both leaves and roots increased under heat stress in bothand salinity stresses, the scavenging system may lose cultivars, but to a greater extent in Penncross. The activities of SOD its function and the balance between producing and and CAT decreased, whereas POD activity increased in both leaves quenching active oxygen species can be disturbed, reand roots, which occurred to a greater extent for Penncross. The sulting in oxidative damage (Bowler et al., 1992; Hodgincreases in MDA content and POD activity under heat stress were son and Raison, 1991; Price et al., 1989; Zhang and greater for leaves than for roots in both cultivars. These results suggest Han, 1997;Zhang and Kirkham, 1994). Whether lipid that decreased activities of antioxidant enzymes could result in an peroxidation of cell membranes is associated with heatincreased level of lipid peroxidation. Thus, decreased activities of stress injury in cool-season grasses, especially creeping antioxidant enzymes could contribute to damage of cell membranes and to leaf senescence as demonstrated by increased EL and reduced bentgrass under close mowing conditions, is not clear. Fv/Fm, and by decreased chlorophyll content during heat stress. Culti-

Proline induces heat tolerance in chickpea (Cicer arietinum L.) plants by protecting vital enzymes of carbon and antioxidative metabolism

“…The elevation of temperature resulted in increase in EL indicating membrane injury, which is reported to be a direct consequence of high temperature (Coria et al 1998). The EL has been reported as a useful indicator of heat stress injury to plants in some earlier studies (Liu and Huang 2000;Gulen and Eris 2004) and our findings in this context match with the similar ones reported in heat-stressed strawberry (Gulen and Eris 2004) and rice (Sohn and Back 2007) plants. The cellular respiration was assessed using 2,3,5 triphenyl tetrazolium chloride (TTC) reduction assay that indicates cellular respiration.…”

“…Heat stress can directly result in denaturation of proteins and enzymes (Kepova et al 2005), membrane damage (Liu and Huang 2000) and can indirectly result in inactivation of enzymes located in the mitochondria and chloroplasts, reduction in protein synthesis and disruption of their membranes (Howarth 2005). One of the prominent effects of heat stress includes oxidative damage due to production of reactive oxygen species like superoxides, lipid peroxides and hydrogen peroxide (Rivero et al 2001, Yin et al 2008).…”

Plant Water Relations: Absorption, Transport and Control Mechanisms

“…These compounds also act in the reduction of reactive oxygen species (ROS) produced under conditions of stress in plants. With the process of tissue dehydration, there is production of ROS, such as the singlet oxygen (1O 2 ), the superoxide radical (O 2 -), hydrogen peroxide (H 2 O 2 ) and the hydroxyl radical (OH-) (Liu & Huang, 2000). Reactive oxygen species (ROSs) are produced from oxygen metabolism and play an important role as indicators in the stress process of water deficit.…”

High temperature-induced oxidative stress inLens culinaris, role of antioxidants and amelioration of stress by chemical pre-treatments

“…A major mechanism of injury is by the generation of reactive oxygen species such as superoxides, hydrogen peroxide and hydroxyl radicals which damage cellular components (Noctor and Foyer 1998;Liu and Huang 2000;Breusegem et al 2001). During the time of temperature stress, reactive oxygen species level can increase dramatically which can result in significant damage to cell structure.…”