Liu Guifu, Zeng Ruizhen, Zhu Haitao, Zhang Zemin, Ding Xiaohua, Zhao Fangming, Li Wentao, Zhang Guiquan
Guangdong Key Lab of Plant Molecular Breeding, South China Agricultural University, 510642, Guangzhou, People's Republic of China.
Theor Appl Genet. 2009 Feb;118(3):443-53. doi: 10.1007/s00122-008-0911-3. Epub 2008 Oct 24.
Nine single segment substitution lines (SSSLs) in rice, which contain quantitative trait loci (QTLs) for tiller number on substituted segments detected in previous studies, were selected as materials to analyse dynamic expression of the QTLs in this study. These SSSLs and their recipient parent, Hua-jing-xian 74 (HJX74), were grown in four different environments and were measured for tiller number at nine different growth stages. An indirect methodology was applied in QTL mapping through analyzing multi-environment phenotypic data. Dynamics of three types of effects (including total effect, main effect, and QE interaction effect) of QTLs was released. It was shown that nine QTLs exhibited statistically significant effects only at certain stages. Effects of a QTL, although insignificant at certain stages, displayed dynamic change with the growth of rice plants. Two common features of nine QTLs were detected, one is no expression within 7 days after transplanting, and the other is opposite expression existed during the whole growth period. Nine QTLs largely focused on expression in certain stages, and accordingly were suggested to partition into three types, expression in prophase, both in prophase and in anaphase, and evenly during the whole stage. It may be reasonable explanation that dynamics of main effects of QTLs are likely due to gene expression selectly at certain times, while dynamics of QE interaction effects of QTLs might attribute to the subrogation of environmental factors. Examination of the association between QE interaction effect and specified environmental factors across stages may provide useful information on how an environmental factor regulates QTL expression.
本研究选取了9个水稻单片段代换系（SSSLs）作为材料，这些代换系在其代换片段上含有前人研究检测到的与分蘖数相关的数量性状基因座（QTLs），用于分析QTLs的动态表达。将这些SSSLs及其受体亲本华粳籼74（HJX74）种植于4种不同环境中，并在9个不同生长阶段测定其分蘖数。通过分析多环境表型数据，采用间接方法进行QTL定位。揭示了QTLs的3种效应（包括总效应、主效应和QE互作效应）的动态变化。结果表明，9个QTLs仅在特定阶段表现出显著效应。一个QTL的效应虽然在某些阶段不显著，但随水稻植株生长表现出动态变化。检测到9个QTLs的两个共同特征，一是移栽后7天内无表达，二是在整个生育期存在相反表达。9个QTLs主要集中在特定阶段表达，据此可分为3种类型，即前期表达、前期和后期均表达以及在整个阶段均匀表达。QTLs主效应的动态变化可能是由于基因在特定时间选择性表达，而QTLs的QE互作效应的动态变化可能归因于环境因子的替代作用，这可能是一个合理的解释。跨阶段考察QE互作效应与特定环境因子之间的关联，可能为环境因子如何调控QTL表达提供有用信息。
