Peng Ze, Zhao Chongbin, Li Shuqing, Guo Yihan, Xu Hongxia, Hu Guibing, Liu Zongli, Chen Xiuping, Chen Junwei, Lin Shunquan, Su Wenbing, Yang Xianghui
State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources and Key Laboratory of Innovation and Utilization of Horticultural Crop Resources in South China (Ministry of Agriculture and Rural Affairs), College of Horticulture, South China Agricultural University, Guangzhou, Guangdong 510642, China.
Institute of Horticulture, Zhejiang Academy of Agricultural Sciences, Hangzhou, Zhejiang 310021, China.
Hortic Res. 2022 Feb 7;9. doi: 10.1093/hr/uhac037.
Fruit weight is an integral part of fruit-quality traits and directly influences commodity values and economic returns of fruit crops. Despite its importance, the molecular mechanisms underlying fruit weight remain understudied, especially for perennial fruit tree crops such as cultivated loquat (Eriobotrya japonica Lindl.). Auxin is known to regulate fruit development, whereas its role and metabolism in fruit development remain obscure in loquat. In this study, we applied a multi-omics approach, integrating whole-genome resequencing-based quantitative trait locus (QTL) mapping with an F1 population, population genomics analysis using germplasm accessions, transcriptome analysis, and metabolic profiling to identify the genomic regions potentially associated with fruit weight in loquat. We identified three major loci associated with fruit weight, supported by both QTL mapping and comparative genomic analysis between small- and big-fruited loquat cultivars. Comparison between two genotypes with contrasting fruit weight performance through transcriptomic and metabolic profiling revealed an important role of auxin in regulating fruit development, especially at the fruit enlarging stage. The multi-omics approach identified two homologs of ETHYLENE INSENSITIVE 4 (EjEIN4) and TORNADO 1 (EjTRN1) as promising candidates controlling fruit weight. Moreover, three single nucleotide polymorphism (SNP) markers were closely associated with fruit weight. Results from this study provided insights from multiple perspectives into the genetic and metabolic controls of fruit weight in loquat. The candidate genomic regions, genes, and sequence variants will facilitate understanding the molecular basis of fruit weight and lay a foundation for future breeding and manipulation of fruit weight in loquat.
果实重量是果实品质性状的一个重要组成部分，直接影响水果作物的商品价值和经济收益。尽管其重要性，但果实重量的分子机制仍未得到充分研究，尤其是对于多年生果树作物，如栽培枇杷（Eriobotrya japonica Lindl.）。已知生长素可调节果实发育，但其在枇杷果实发育中的作用和代谢仍不清楚。在本研究中，我们应用了多组学方法，将基于全基因组重测序的数量性状位点（QTL）定位与F1群体相结合，利用种质资源进行群体基因组分析、转录组分析和代谢谱分析，以鉴定枇杷中可能与果实重量相关的基因组区域。我们通过QTL定位和小果与大果枇杷品种之间的比较基因组分析，确定了三个与果实重量相关的主要位点。通过转录组和代谢谱分析比较两个果实重量表现不同的基因型，揭示了生长素在调节果实发育中的重要作用，尤其是在果实膨大阶段。多组学方法鉴定出乙烯不敏感4（EjEIN4）和TORNADO 1（EjTRN1）的两个同源基因是控制果实重量的有希望的候选基因。此外，三个单核苷酸多态性（SNP）标记与果实重量密切相关。本研究结果从多个角度为枇杷果实重量的遗传和代谢控制提供了见解。候选基因组区域、基因和序列变异将有助于理解果实重量的分子基础，并为未来枇杷果实重量的育种和调控奠定基础。
