Comparative transcriptomics analysis at the key stage of maize ear development dissect heterosis
Comparative transcriptomics analysis at the key stage of maize ear development dissect heterosis
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DOI：
10.1002/tpg2.20293
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发表时间：
2022-12-07
期刊：
影响因子：
4.2
通讯作者：
Tang，Jihua
中科院分区：
文献类型：
--
作者：
Wang，Liangfa;Li，Juan;Tang，Jihua
与玉米（Zea mays L.）雌花序发育过程决定着籽粒产量，如穗行数、穗长、行粒数等。花序分生组织活力与产量构成因素呈显著正相关。为寻找穗部杂种优势形成的关键时期，以豫单888及其亲本的幼穗（IM期至花分生组织（FM）期）为材料，进行表型分析和转录组学比较分析。豫单888幼穗长在IM期符合加性（中亲）模型，但在SPM期表现出较高的亲本显性。转录组的比较分析表明，不同发育阶段的加性和非加性表达模式之间存在显着差异。在每个阶段，不同的母本或父本基因（ABF）（仅在一个亲本系及其杂种中表达，但在另一个系中沉默的基因）的数量大于ABF 1（在两个亲本系中表达，但在杂种中沉默的基因）。基因本体（GO）富集表明，细胞氧化还原稳态基因在杂种中具有超显性表达模式，对杂种优势有重要贡献。在此基础上，建立了穗长杂种优势网络。穗长杂种优势拐点的发现，使我们可以推测，IM向SPM的过渡状态可能是穗长杂种优势的起点。这些结果加深了对玉米穗长杂种优势的认识。
Important traits related to maize (Zea maysL.) grain yield, such as kernel row number, ear length, kernel number per row, are determined during the development of female inflorescence. There is a significant positive correlation between yield component and the activity of inflorescence meristem (IM). To find the key stage of heterosis in the development of the ear, immature ears (from the IM stage until the end of the floral meristem [FM] stage) of Yudan888 and its parent lines were sampled to assay phenotype and for comparative transcriptomics analysis. The immature ear length of Yudan888 at the IM stage fitted an additive (mid‐parental) model, but it showed high parental dominance at the spikelet‐pair meristem (SPM) stage. Comparative analysis of transcriptomes suggested significant differences between additive and nonadditive expression patterns for different developmental stages. The number of distinct maternal or paternal genes (DMP) (genes expressed only in one parental line and their hybrid but silenced in another line) was greater than ABF1 (genes expressed in both parental lines but silenced in hybrid) at each stage. Gene Ontology (GO) enrichment suggested that the cell redox homeostasis genes with overdominance expression patterns in hybrids have an important contribution to heterosis. According to our research, an ear length heterosis network was established. The discovery of the inflection point for ear length heterosis allows us for inferring that the transition state of IM to SPM may be the starting point of ear length heterosis. These findings improved the understanding of maize ear length heterosis.