Guangdong Laboratory of Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture and Rural Affairs, Agricultural Synthetic Biology Center, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, 518172, China.
Yunnan Key Laboratory of Potato Biology, The AGISCAAS-YNNU Joint Academy of Potato Sciences, Yunnan Normal University, Kunming, 650500, China.
J Integr Plant Biol. 2022 Mar;64(3):671-687. doi: 10.1111/jipb.13211. Epub 2022 Feb 28.
Heterosis is a fundamental biological phenomenon characterized by the superior performance of hybrids over their parents. Although tremendous progress has been reported in seed crops, the molecular mechanisms underlying heterosis in clonally propagated crops are largely unknown. Potato (Solanum tuberosum L.) is the most important tuber crop and an ongoing revolution is transforming potato from a clonally propagated tetraploid crop into a seed-propagated diploid hybrid potato. In our previous study, we developed the first generation of highly homozygous inbred lines of potato and hybrids with strong heterosis. Here, we integrated transcriptome, metabolome, and DNA methylation data to explore the genetic and molecular basis of potato heterosis at three developmental stages. We found that the initial establishment of heterosis in diploid potato was mainly due to dominant complementation. Flower color, male fertility, and starch and sucrose metabolism showed obvious gene dominant complementation in hybrids, and hybrids devoted more energy to primary metabolism for rapid growth. In addition, we identified ~2 700 allele-specific expression genes at each stage, which likely function in potato heterosis and might be regulated by CHH allele-specific methylation level. Our multi-omics analysis provides insight into heterosis in potato and facilitates the exploitation of heterosis in potato breeding.
杂种优势是一种基本的生物学现象，其特点是杂种比其父母具有更好的表现。尽管在种子作物中已经报道了巨大的进展，但在无性繁殖作物中杂种优势的分子机制在很大程度上尚不清楚。马铃薯（Solanum tuberosum L.）是最重要的块茎作物，一场正在进行的革命正在将马铃薯从无性繁殖的四倍体作物转变为有性繁殖的二倍体杂交马铃薯。在我们之前的研究中，我们开发了第一代高度纯合的马铃薯自交系和具有强杂种优势的杂种。在这里，我们整合了转录组、代谢组和 DNA 甲基化数据，以探索马铃薯在三个发育阶段杂种优势的遗传和分子基础。我们发现，在二倍体马铃薯中杂种优势的初步建立主要是由于显性互补。花色、雄性育性以及淀粉和蔗糖代谢在杂种中表现出明显的基因显性互补，杂种为快速生长而投入更多的能量进行初级代谢。此外，我们在每个阶段鉴定了大约 2700 个等位基因特异性表达基因，这些基因可能在马铃薯杂种优势中发挥作用，并且可能受到 CHH 等位基因特异性甲基化水平的调控。我们的多组学分析为马铃薯杂种优势提供了深入的了解，并促进了马铃薯杂种优势在育种中的利用。
