Hideg Éva, Rosenqvist Eva, Váradi Gyula, Bornman Janet, Vincze Éva
Institute of Plant Biology, Biological Research Centre, PO Box 521, H-6701 Szeged, Hungary.
Department of Horticulture, Danish Institute of Agricultural Sciences, Kirstinebjergvej 10, PO Box 102, DK-5792 Årslev, Denmark.
Funct Plant Biol. 2006 Feb;33(1):77-90. doi: 10.1071/FP05085.
In order to investigate the role of potential genotypic differences in three economically important barley cultivars, experiments were carried out to determine the influence of supplemental ultraviolet-B (UV-B, 280-320 nm) radiation on reactive oxygen species (ROS), antioxidant activity and photosynthesis. Greenhouse-grown barley (Hordeum vulgare L.) cultivars 'Cork', 'Prestige' and 'Golden Promise' showed different responses to supplemental 280-320 nm (UV-B) representing 100, 138 and 238% levels of ambient biologically active UV-B radiation, respectively. Among the three cultivars studied, cv. Golden Promise was the most tolerant to UV-B, cv. Prestige was slightly more sensitive than cv. Cork. A comparison with the other two cultivars showed that under supplemental UV-B, Golden Promise leaves (i) retained a higher quantum yield of photosynthesis under photosynthetically active radiation (PAR, 400-700 nm) corresponding to growth conditions; (ii) had the smallest decrease in both electron transport rate and non-photochemical quenching under high PAR; (iii) contained less oxidized ascorbate [measured as dehydroascorbate or electron paramagnetic resonance (EPR) detectable monodehydroascorbate radicals] than either Cork or Prestige. Under the highest UV-B level applied, Golden Promise leaves maintained the same activity of both monodehydroascorbate-reductase (MDAR) and ascorbate-peroxidase (APX) enzymes, as untreated controls, while MDAR markedly decreased in the other two cultivars and APX slightly increased in cv. Prestige. These features, together with the observation of directly EPR-trappable free radicals and the light-independent accumulation of monodehydroascorbate radicals in Cork and Prestige but not in Golden Promise leaves under high UV-B suggest that Golden Promise plants suffered less oxidative stress than the two other cultivars.
为了研究三种经济价值重要的大麦品种潜在基因型差异的作用，开展了实验以确定补充紫外线-B（UV-B，280 - 320纳米）辐射对活性氧（ROS）、抗氧化活性和光合作用的影响。温室种植的大麦（Hordeum vulgare L.）品种‘Cork’、‘Prestige’和‘Golden Promise’对分别代表环境生物活性UV-B辐射水平100%、138%和238%的补充280 - 320纳米（UV-B）表现出不同的反应。在所研究的三个品种中，‘Golden Promise’品种对UV-B耐受性最强，‘Prestige’品种比‘Cork’品种稍敏感。与其他两个品种相比表明，在补充UV-B条件下，‘Golden Promise’叶片（i）在对应生长条件的光合有效辐射（PAR，400 - 700纳米）下保持较高的光合作用量子产率；（ii）在高光合有效辐射下电子传递速率和非光化学猝灭的下降幅度最小；（iii）与‘Cork’或‘Prestige’相比，所含氧化型抗坏血酸[以脱氢抗坏血酸或电子顺磁共振（EPR）可检测的单脱氢抗坏血酸自由基测量]更少。在施加的最高UV-B水平下，‘Golden Promise’叶片的单脱氢抗坏血酸还原酶（MDAR）和抗坏血酸过氧化物酶（APX）酶活性与未处理对照相同，而其他两个品种中MDAR显著下降，‘Prestige’品种中APX略有增加。这些特征，连同在高UV-B条件下直接通过EPR捕获自由基的观察结果以及‘Cork’和‘Prestige’叶片而非‘Golden Promise’叶片中单脱氢抗坏血酸自由基的光独立积累表明，‘Golden Promise’植株比其他两个品种遭受的氧化应激更小。
