tase and CAT are the most effective antioxidant enzymes in scavenging AOS (Bowler et al., 1992).Turf quality of Kentucky bluegrass (Poa pratensis L.) often declines during summer when temperatures exceed its optimum range.Various cultural practices such as irrigation, fertiliza-This study was designed to determine whether application of salicylic tion, and soil cultivation have been extensively investiacid (SA) to the shoots and soil could improve heat tolerance of gated to improve turf performance in cool-season turf-Kentucky bluegrass, and to investigate whether SA-induced heat tolgrass during summer stress. However, limited information erance is related to changes in antioxidant activities. Effects of SA is available on the use of hormones or plant growth reguat different concentrations (0, 0.1, 0.25, 0.5, 1, and 1.5 mmol) on heat lators in heat stress management for cool-season turftolerance were examined in Kentucky bluegrass exposed to 46؇C for 72 h in a growth chamber. Influences of SA on the production of grasses and results vary with chemistry types. Kentucky active oxygen species (AOS), superoxide anion (O 2 . Ϫ ), and hydrogen bluegrass plants treated with trinexapac-ethyl, a synperoxide (H 2 O 2 ), and activities of antioxidant enzymes, superoxide thetic gibberellic acid inhibitor, were less heat tolerant dismutase (SOD), and catalase (CAT), were examined. Among SA than untreated plants (Heckman et al., 2002). Humic concentrations, 0.25 mmol was most effective in enhancing heat tolersubstances and seaweed extracts that contain phytohorance in Kentucky bluegrass, which was manifested by improved regrowth potential following heat stress of 72 h and maintenance of mones were reported to improve turfgrass stress tolerleaf water content at 77% during the 12-h stress period similar to that ance in various turfgrass species (Zhang et al., 2003a, under normal temperature conditions. The O 2 . Ϫ generating rate in-2003b). Other organic compounds such as ascorbic acid creased significantly at 6 h of heat stress, and SOD activity increased were used as free radical scavengers to alleviate oxidasignificantly at 2 h but decreased to the control level at 6 h of heat tive stress in various species (Zhang and Kirkham, stress in SA-untreated plants. The SA application suppressed the 1996). Salicylic acid has been defined as a new potential increase of O 2 . Ϫ generating rate and enhanced SOD activity significantly at 2 and 6 h of heat stress, respectively. The SA application decreased plant hormone (Raskin, 1992a) and found to play an H 2 O 2 level significantly at 2 and 12 h of heat stress, and increased important role in disease resistance (Raskin, 1992b) and CAT activity significantly within 12 h of heat stress. The results suggest

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Iron homeostasis is essential for maintaining cellular function in a wide range of cell types. However, whether iron affects the thermogenic properties of adipocytes is currently unknown. Using integrative analyses of multi‐omics data, transferrin receptor 1 (Tfr1) is identified as a candidate for regulating thermogenesis in beige adipocytes. Furthermore, it is shown that mice lacking Tfr1 specifically in adipocytes have impaired thermogenesis, increased insulin resistance, and low‐grade inflammation accompanied by iron deficiency and mitochondrial dysfunction. Mechanistically, the cold treatment in beige adipocytes selectively stabilizes hypoxia‐inducible factor 1‐alpha (HIF1α), upregulating the Tfr1 gene, and thermogenic adipocyte‐specific Hif1α deletion reduces thermogenic gene expression in beige fat without altering core body temperature. Notably, Tfr1 deficiency in interscapular brown adipose tissue (iBAT) leads to the transdifferentiation of brown preadipocytes into white adipocytes and muscle cells; in contrast, long‐term exposure to a low‐iron diet fails to phenocopy the transdifferentiation effect found in Tfr1‐deficient mice. Moreover, mice lacking transmembrane serine protease 6 (Tmprss6) develop iron deficiency in both inguinal white adipose tissue (iWAT) and iBAT, and have impaired cold‐induced beige adipocyte formation and brown fat thermogenesis. Taken together, these findings indicate that Tfr1 plays an essential role in thermogenic adipocytes via both iron‐dependent and iron‐independent mechanisms.

Effects of exogenous salicylic acid (SA) on plant growth, contents of Na, K, Ca and Mg, activities of superoxide dismutase (SOD), guaiacol peroxidase (GPX), ascorbate peroxidase (APX), dehydroascorbate reductase (DHAR), glutathione reductase (GR) and catalase (CAT), and contents of ascorbate and glutathione were investigated in tomato (Lycopersicon esculentum L.) plants treated with 100 mM NaCl. NaCl treatment significantly increased H 2 O 2 content and lipid peroxidation indicated by accumulation of thiobarbituric acid reactive substances (TBARS). A foliar spray of 1 mM SA significantly decreased lipid peroxidation caused by NaCl and improved the plant growth. This alleviation of NaCl toxicity by SA was related to decreases in Na contents, increases in K and Mg contents in shoots and roots, and increases in the activities of SOD, CAT, GPX and DHAR and the contents of ascorbate and glutathione.