Applying genotyping (TILLING) and phenotyping analyses to elucidate gene function in a chemically induced sorghum mutant population
Applying genotyping (TILLING) and phenotyping analyses to elucidate gene function in a chemically induced sorghum mutant population
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DOI：
10.1186/1471-2229-8-103
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发表时间：
2008-10-14
影响因子：
5.3
通讯作者：
Burke, John
中科院分区：
文献类型：
--
作者：
Xin, Zhanguo;Wang, Ming Li;Burke, John
背景：Sorcium [Sorcium bicolor（L.）Moench]被列为第五大最重要的粮食作物，并作为世界大部分地区的主要主食和饲料资源，特别是在干旱和半干旱地区。最近高粱研究的激增是由于其对干旱/高温胁迫的耐受性及其作为生物能源原料的强大潜力。高粱基因组测序的完成为高粱功能基因组学研究开辟了新的途径。然而，遗传资源，特别是突变株系的可用性是有限的。高粱种质的化学诱变，然后通过筛选重要农艺性状的突变体，代表了解决这一限制的快速有效的手段。新的感兴趣的基因中的诱导突变可以有效地评估使用称为靶向诱导局部损伤基因组（TILLING）的技术。结果：高粱突变体群体由1,600行从自交系BTx623通过处理与化学试剂甲磺酸乙酯（EMS）。在田间试验中，从M-2和M-3品系中观察到许多具有改变的形态和农艺性状的表型。使用四个靶基因通过TILLING分析了768个突变株系的子集。总共鉴定出5个突变，计算出的突变密度为1/526 kb。在两个独立的突变株系中，在编码咖啡酸O-甲基转移酶（COMT）的基因中检测到两个通过TILLING鉴定并通过测序验证的突变。这两个突变株系分离预期的棕色中脉（BMR）表型，改变木质素含量和增加消化率的性状。结论：TILLING作为一种反向遗传方法已成功地应用于高粱。在田间观察到的突变体表型的多样性，和从TILLING计算的诱导突变的密度表明，该突变体群体代表了高粱研究界成员的有用资源。此外，TILLING已被证明是适用于高粱功能基因组学通过评估一个小子集的EMS诱导的突变株系。
Background: Sorghum [Sorghum bicolor (L.) Moench] is ranked as the fifth most important grain crop and serves as a major food staple and fodder resource for much of the world, especially in arid and semi-arid regions. The recent surge in sorghum research is driven by its tolerance to drought/heat stresses and its strong potential as a bioenergy feedstock. Completion of the sorghum genome sequence has opened new avenues for sorghum functional genomics. However, the availability of genetic resources, specifically mutant lines, is limited. Chemical mutagenesis of sorghum germplasm, followed by screening for mutants altered in important agronomic traits, represents a rapid and effective means of addressing this limitation. Induced mutations in novel genes of interest can be efficiently assessed using the technique known as Targeting Induced Local Lesion IN Genomes (TILLING).Results: A sorghum mutant population consisting of 1,600 lines was generated from the inbred line BTx623 by treatment with the chemical agent ethyl methanesulfonate (EMS). Numerous phenotypes with altered morphological and agronomic traits were observed from M-2 and M-3 lines in the field. A subset of 768 mutant lines was analyzed by TILLING using four target genes. A total of five mutations were identified resulting in a calculated mutation density of 1/526 kb. Two of the mutations identified by TILLING and verified by sequencing were detected in the gene encoding caffeic acid O-methyltransferase (COMT) in two independent mutant lines. The two mutant lines segregated for the expected brown midrib (bmr) phenotype, a trait associated with altered lignin content and increased digestibility.Conclusion: TILLING as a reverse genetic approach has been successfully applied to sorghum. The diversity of the mutant phenotypes observed in the field, and the density of induced mutations calculated from TILLING indicate that this mutant population represents a useful resource for members of the sorghum research community. Moreover, TILLING has been demonstrated to be applicable for sorghum functional genomics by evaluating a small subset of the EMS-induced mutant lines.