Genotypic variation in tolerance to elevated ozone in rice: dissection of distinct genetic factors linked to tolerance mechanisms
Genotypic variation in tolerance to elevated ozone in rice: dissection of distinct genetic factors linked to tolerance mechanisms
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DOI：
10.1093/jxb/ern222
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发表时间：
2008-10-01
影响因子：
6.9
通讯作者：
Wissuwa, Matthias
中科院分区：
文献类型：
--
作者：
Frei, Michael;Tanaka, Juan Pariasca;Wissuwa, Matthias
在许多亚洲国家，对流层臭氧浓度正在增加，预计将达到对作物生产产生不利影响的水平。耐臭氧水稻（Oryza sativa L.）因此，品种是防止未来产量损失的关键。本研究的目的是评估水稻耐臭氧的基因型变异，确定数量性状位点（QTL）赋予的宽容，并与QTL的生理耐受机制。根据叶片褐变和干重损失评估了23个品种对臭氧浓度升高（120 nl l（-1））的反应。传统品种'Kasalath'是高度耐受的，而现代品种'日本晴'表现出显着的干重减少。利用Nipponbare/Kasalath/Nipponbare作图群体，鉴定了6个与臭氧浓度升高耐受性相关的QTL，其中3个QTL在Nipponbare/Kasalath代换系（SL）中得到证实。在第3和第9染色体上定位了2个与叶片青铜化相关的QTL。三号染色体上的Kasalath等位基因增加青铜化，而九号染色体上的等位基因减少青铜化。当暴露于臭氧时，携带这些对照QTL的SL在叶片抗坏血酸（阿萨）含量上存在显著差异，表明阿萨是对抗臭氧诱导的氧化损伤的主要抗氧化剂。一个进一步证实的QTL与干重相关位于第八染色体上，其中Kasalath等位基因增加相对干重。与轮回亲本日本晴相比，携带该QTL的SL在臭氧暴露下表现出较小的净光合速率降低。虽然这些QTL对作物产量的影响尚未确定，但它们的鉴定可能是开发耐臭氧水稻品种的重要的第一步。
Tropospheric ozone concentrations are increasing in many Asian countries and are expected to reach levels that adversely affect crop production. Developing ozone-tolerant rice (Oryza sativa L.) varieties is therefore essential to prevent yield losses in the future. The aims of this study were to assess genotypic variation for ozone tolerance in rice, to identify quantitative trait loci (QTL) conferring tolerance, and to relate QTLs to physiological tolerance mechanisms. The response of 23 varieties to elevated ozone (120 nl l(-1)) was assessed based on leaf bronzing and dry weight loss. The traditional variety 'Kasalath' was highly tolerant, whereas the modern variety 'Nipponbare' showed significant dry weight reductions. Using the Nipponbare/Kasalath/Nipponbare mapping population, six QTLs associated with tolerance to elevated ozone were identified, of which three were subsequently confirmed in Nipponbare/Kasalath substitution lines (SLs). Two QTLs associated with leaf bronzing were located on chromosomes three and nine. Kasalath alleles on chromosome three increased bronzing, while alleles on chromosome nine reduced bronzing. SLs carrying these contrasting QTLs differed significantly in leaf ascorbic acid (AsA) content when exposed to ozone, suggesting AsA as a principal antioxidant counteracting ozone-induced oxidative damage. A further confirmed QTL related to dry weight was located on chromosome eight, where the Kasalath allele increased relative dry weight. A SL carrying this QTL exhibited a less reduced net photosynthetic rate under ozone exposure compared with its recurrent parent Nipponbare. Although the effect of these QTLs on crop yield has not yet been established, their identification could be an important first step in developing ozone-tolerant rice varieties.