近60年来 20 个冬小麦品种叶片对臭氧生化、生理和生长反应的基因型差异 Biwas D. K., 徐宏 , 李永庚 , 孙家柱 , 王贤忠 , 韩兴国 , 蒋高明 * 中国科学院植物学研究所植被与环境变化重点实验室,中国北京 100093 南辛村 20 中国科学院遗传与发育生物学研究所植物细胞与 遗传 工程国家重点实验室,北京, 100101 印第安 那 大学生物学系,普渡大学,印第安 那 波利斯, 723 W.Michigan St. , Indianapolis , IN 46202 , USA 山东农业大学作物科学学院 , 泰安岱宗大街 61 号 全球变化生物学 , 2008, 14: 46-59. ( 影响因子: 8.88) 【 摘要 】 东亚城市周边地区臭氧( O3 )浓度升高,足以降低作物产量。然而,冬小麦 O3 敏感性与品种推广年代的基因型差异却鲜为人知。本文报道了近 60 年来中国 20 个冬小麦品种对 O3 敏感性基因型变化,揭示了 O3 的诱导机制。小麦植株暴露于高 O3 ( 82 ppb O3 , 7h d-1 )或木炭过滤空气( 5 ppb O3 )中,在开顶式同化箱内处理 21 天。通过抗氧化活性、蛋白质改变、膜脂过氧化、气体交换、叶绿素含量、暗呼吸和生物量变化来评价不同年代推广的小麦品质对 O3 的响应。结果表明, O3 显著降低了叶片抗坏血酸( 14% )和可溶性蛋白( 22% )含量,但过氧化物酶活性( +46% )和丙二醛( + 38% )显著增加。高浓度 O3 降低了光饱和净光合速率(- 24% )、气孔导度(- 8% )和总叶绿素含量(- 11% ),同时刺激了暗呼吸( +28% ),胞间 CO2 浓度( +39% )升高。 O3 也降低了植物整体生长量,但根( -32% )生物量比茎( -17% )的生物量受影响更大。对 O3 的潜在敏感性存在显著的基因型差异,与观察到的 O3 耐受性无关。冬小麦品种对 O3 的敏感性随推广年份的增加而增加,并与 O3 暴露植株的气孔导度和暗呼吸有关。 O3 诱导的光合速率下降主要是由于叶肉细胞活性下降和细胞膜完整性丧失,细胞间 CO2 浓度升高和脂质过氧化增加。结果表明,气孔导度高、抗氧化能力降低、暗呼吸水平低,导致对蛋白质的氧化损伤和细胞膜的完整性,导致了新品种对 O3 敏感性增强。 关键词:抗氧化剂、暗呼吸、生长、臭氧敏感性、气孔导度、冬小麦、推广年代 Genotypic differences in leaf biochemical, physiological and growth responses to ozone in 20 winter wheat cultivars released over the past 60 years Global Change Biology , 2008, 14: 46-59. ( IF=8.88) Biwas D. K., Xu H., Li Y. G., Sun J. Z., Wang X. Z., Han X. G. Jiang G. M* Abstract Ozone (O3) concentrations in periurban areas in East Asia are sufficiently high to decrease crop yield. However, little is known about the genotypic differences in O3 sensitivity in winter wheat in relation to year of cultivar release. This paper reports genotypic variations in O3 sensitivity in 20 winter wheat cultivars released over the past 60 years in China highlighting O3-induced mechanisms. Wheat plants were exposed to elevated O3 (82 ppb O3, 7 h day−1) or charcoal-filtered air (5 ppb O3) for 21 days in open top chambers. Responses to O3 were assessed by the levels of antioxidative activities, protein alteration, membrane lipid peroxidation, gas exchange, leaf chlorophyll, dark respiration and growth. We found that O3 significantly reduced foliar ascorbate (−14%) and soluble protein (−22%), but increased peroxidase activity (+46%) and malondialdehyde (+38%). Elevated O3 depressed light saturated net photosynthetic rate (−24%), stomatal conductance (−8%) and total chlorophyll (−11%), while stimulated dark respiration (+28%) and intercellular CO2 concentration (+39%). O3 also reduced overall plant growth, but to a greater extent in root (−32%) than in shoot (−17%) biomass. There was significant genotypic variation in potential sensitivity to O3 that did not correlate to observed O3 tolerance. Sensitivity to O3 in cultivars of winter wheat progressed with year of release and correlated with stomatal conductance and dark respiration in O3-exposed plants. O3-induced loss in photosynthetic rate was attributed primarily to impaired activity of mesophyll cells and loss of integrity of cellular membrane as evidenced by increased intercellular CO2 concentration and lipid peroxidation. Our findings demonstrated that higher sensitivity to O3 in the more recently released cultivars was induced by higher stomatal conductance, larger reduction in antioxidative capacity and lower levels of dark respiration leading to higher oxidative damage to proteins and integrity of cellular membranes. Key words: antioxidants, dark respiration, growth, ozone sensitivity, stomatal conductance, Triticum aestivum L., winter wheat, year of release
今天打开邮箱又收到了NCBI系统发来的关注文章:共计5篇,看到一篇刚刚发表在PLOS one上的一篇关于中国冬小麦骨干系的遗传多态性、群体结构和连锁不平衡衰退的相关内容研究 “Genetic Diversity, Population Structure and Linkage Disequilibrium in Elite Chinese Winter Wheat Investigated with SSR Markers.” ,该研究群体包含90个中国冬小麦骨干系,应用269个SSR标记,对小麦的A,B,D基因组进行研究,计算了遗传座位的多态性,划分了三个亚群,计算了LD decay值,整个工作中规中矩,从table到figure,都做的很漂亮。结果和讨论部分目标明确,结论清晰,是近年来国内冬小麦骨干系群体研究的一篇范例,是想要学习群体结构分析和关联分析的同学们的良好教材,也是进行群体遗传学研究同学们实验思路和文章流程的学习对象。 目前我们的实验技术方法和手段越来越多,通量越来越高,数据越来越海量,但是这并不表示我们的所有研究都要运用高通量方法得到海量数据,进而分析得出的结论才是有意义的。科研工作者应当合理利用现有的方法和手段,最省时省力省钱地达到预期的实验效果。这篇文章的实验设计和实验方法就是一个十分合理的设计结合,90个冬小麦骨干系具有良好的代表性,269个SSR标记的检测也很好的平衡了实验的工作量和标记的需求密度这一重要问题,进而得出了具有意义的实验结果。相比动辄群体几百,标记上千的实验来说,该实验可谓是浓缩的精华,毕竟标记无穷匮,经费要珍惜,结论要及时。我们都要经历这样的过程:懂得做实验——做好实验——多快好省地做实验。这就如同武林高手简单的轻描淡写、毫无花俏的一招能够化腐朽为神奇。