背景:已知生长素在甘薯的块茎化过程中起作用(Ipomoeabatatas[L.]林。),这些作用是由各种生长素信号基因家族介导的。在这项研究中,对甘薯基因组进行分析以鉴定ARF,Aux/IAA,该作物中的GH3和SAUR生长素信号基因家族成员。
结果:总共29个ARF,39Aux/IAA,获得13个GH3和200个SAUR序列,并对其生化特性和基因表达谱进行了分析。根据外显子-内含子结构,序列相对保守,主题分析,和系统发育树的构建。对纤维根和贮藏根中基因的计算机表达分析表明,许多序列在结节根和非结节根中没有差异表达。然而,一些ARF,Aux/IAA,与非结节性纤维根相比,结节性贮藏根中的SAUR基因上调,而许多GH3基因下调。此外,这些基因在各种植物部位表达,一些基因在芽中高度表达,叶子,和茎,而其他人在根中有较高的表达。其中一些基因在植物对各种激素处理和非生物胁迫的反应过程中上调。还进行了基因表达的定量RT-PCR确认,结果与计算机模拟分析一致。预测了差异表达基因的蛋白质-蛋白质相互作用网络,这表明这些基因很可能是控制结节形成的复杂调控网络的一部分。这些结果证实了现有研究的结果,这些研究表明生长素信号基因在甘薯的生长和发育中具有许多作用。
结论:这项研究提供了有关叶果中生长素信号基因家族的有用信息,并为进一步研究生长素信号在块茎化和植物发育中的作用提供了可能的候选者。
BACKGROUND: Auxins are known to have roles in the tuberization process in sweet potato (Ipomoea batatas [L.] Lam.) and these effects are mediated by various auxin signalling gene families. In this study, an analysis of the sweet potato genome was performed to identify the ARF, Aux/IAA, GH3, and
SAUR auxin signalling gene family members in this crop.
RESULTS: A total of 29 ARF, 39 Aux/IAA, 13 GH3, and 200
SAUR sequences were obtained, and their biochemical properties and gene expression profiles were analysed. The sequences were relatively conserved based on exon-intron structure, motif analysis, and phylogenetic tree construction. In silico expression analyses of the genes in fibrous and storage roots indicated that many sequences were not differentially expressed in tuberizing and non-tuberizing roots. However, some ARF, Aux/IAA, and
SAUR genes were up-regulated in tuberizing storage roots compared to non-tuberizing fibrous roots while many GH3 genes were down-regulated. Additionally, these genes were expressed in a variety of plant parts, with some genes being highly expressed in shoots, leaves, and stems while others had higher expression in the roots. Some of these genes are up-regulated during the plant\'s response to various hormone treatments and abiotic stresses. Quantitative RT-PCR confirmation of gene expression was also conducted, and the results were concordant with the in silico analyses. A protein-protein interaction network was predicted for the differentially expressed genes, suggesting that these genes likely form part of a complex regulatory network that controls tuberization. These results confirm those of existing studies that show that auxin signalling genes have numerous roles in sweet potato growth and development.
CONCLUSIONS: This study provides useful information on the auxin signalling gene families in Ipomoea batatas and suggests putative candidates for further studies on the role of auxin signalling in tuberization and plant development.