Molecular Breeding Laboratory, Division of Plant Breeding and Genetics, Rice Research Institute, Kala Shah Kaku, Sheikhupura, Pakistan.
Molecular Breeding Laboratory, Division of Plant Breeding and Genetics, Rice Research Institute, Kala Shah Kaku, Sheikhupura, Pakistan.
Plant Sci. 2019 Nov;288:110214. doi: 10.1016/j.plantsci.2019.110214. Epub 2019 Aug 8.
Biofortification of staple crops with essential micronutrients is the sustainable way to overcome the hidden hunger. A large number of quantitative trait loci (QTL) linked with grain micronutrient contents have been reported in different mapping studies. Identification of consistent QTLs across diverse genetic backgrounds is useful for candidate gene analysis and marker assisted selection of target traits. In this study, an up to date meta-analysis of grain iron and zinc associated QTLs was performed and 48 meta-QTLs (MQTLs) distributed across 12 rice chromosomes were identified. The 95% confidence intervals of identified genomic regions were significantly narrower than the average of their corresponding original QTLs. A total of 9308 genes/transcripts physically located within or near MQTL regions were retrieved and through prioritization of candidate genes (CGs) 663 non-redundant iron and zinc CGs were selected and studied in detailed. Several functionally characterized iron and zinc homoeostasis related genes e.g OsATM3, OsDMAS1, OsFRO2, OsNAS1-3, OsVIT2, OsYSL16, OsZIP3 and OsZIP7 were also included in our MQTL analysis. More than 64% genes were enriched with zinc and iron binding gene ontology terms and were involved in oxidation reduction process, carbohydrate metabolic process, regulation of transcription, trans-membrane transport, response to oxidative stress, cell redox homeostasis and proteolysis etc. In-silico transcriptomic analysis of rice identified 260 CGs which were regulated in response to iron and zinc stresses. We also identified at least 37 genes which were differentially expressed under both stress conditions and majority of these have not been studied in detailed before. Our results strongly indicate that majority of the MQTLs identified in this study are hotspots for grain iron and zinc concentration and are worth of intensive functional studies in near future.
利用必需微量营养素对主食作物进行生物强化是克服隐性饥饿的可持续方法。在不同的作图研究中已经报道了大量与谷物微量营养素含量相关的数量性状位点(QTL)。在不同的遗传背景下鉴定一致的 QTL 对于候选基因分析和目标性状的标记辅助选择是有用的。在这项研究中，对与谷物铁和锌相关的 QTL 进行了最新的荟萃分析，共鉴定到 48 个分布在 12 条水稻染色体上的 meta-QTL (MQTL)。鉴定的基因组区域的 95%置信区间明显小于其相应原始 QTL 的平均值。总共检索到 9308 个物理上位于 MQTL 区域内或附近的基因/转录本，并通过对候选基因(CG)进行优先级排序，选择并详细研究了 663 个非冗余的铁和锌 CG。一些功能表征的铁和锌同源平衡相关基因，例如 OsATM3、OsDMAS1、OsFRO2、OsNAS1-3、OsVIT2、OsYSL16、OsZIP3 和 OsZIP7，也包含在我们的 MQTL 分析中。超过 64%的基因富含锌和铁结合的基因本体术语，并参与氧化还原过程、碳水化合物代谢过程、转录调控、跨膜运输、对氧化应激的反应、细胞氧化还原平衡和蛋白水解等。水稻的计算机转录组分析鉴定出 260 个 CGs，它们受铁和锌胁迫的调控。我们还鉴定出至少 37 个基因在两种胁迫条件下差异表达，其中大多数基因以前没有进行过详细研究。我们的结果强烈表明，本研究中鉴定的大多数 MQTL 是谷物铁和锌浓度的热点，值得在不久的将来进行深入的功能研究。
