Márquez Gutiérrez Robert, Cherubino Ribeiro Thales Henrique, de Oliveira Raphael Ricon, Benedito Vagner Augusto, Chalfun-Junior Antonio
Laboratory of Plant Molecular Physiology, Plant Physiology Sector, Department of Biology, Federal University of Lavras (UFLA), Lavras 37200-900, MG, Brazil.
Laboratory of Plant Functional Genetics, Plant and Soil Sciences Division, 3425 Agricultural Sciences Building, West Virginia University, Morgantown, WV 26506-6108, USA.
Plants (Basel). 2022 May 3;11(9):1237. doi: 10.3390/plants11091237.
MADS-box transcription factors (TFs) are involved in multiple plant development processes and are most known during the reproductive transition and floral organ development. Very few genes have been characterized in the genome of L. (Cannabaceae), an important crop for the pharmaceutical and beverage industries. The MADS-box family has not been studied in this species yet. We identified 65 MADS-box genes in the hop genome, of which 29 encode type-II TFs (27 of subgroup MIKC and 2 MIKC*) and 36 type-I proteins (26 α, 9 β, and 1 γ). Type-II MADS-box genes evolved more complex architectures than type-I genes. Interestingly, we did not find FLOWERING LOCUS C (FLC) homologs, a transcription factor that acts as a floral repressor and is negatively regulated by cold. This result provides a molecular explanation for a previous work showing that vernalization is not a requirement for hop flowering, which has implications for its cultivation in the tropics. Analysis of gene ontology and expression profiling revealed genes potentially involved in the development of male and female floral structures based on the differential expression of ABC homeotic genes in each whorl of the flower. We identified a gene exclusively expressed in lupulin glands, suggesting a role in specialized metabolism in these structures. , this work contributes to understanding the evolutionary history of MADS-box genes in hop, and provides perspectives on functional genetic studies, biotechnology, and crop breeding.
MADS盒转录因子（TFs）参与多种植物发育过程，在生殖转变和花器官发育过程中最为人所知。在大麻科的重要作物啤酒花的基因组中，只有极少数基因得到了表征。该物种的MADS盒家族尚未得到研究。我们在啤酒花基因组中鉴定出65个MADS盒基因，其中29个编码II型TFs（27个属于MIKC亚组，2个属于MIKC*），36个编码I型蛋白（26个α型、9个β型和1个γ型）。II型MADS盒基因比I型基因进化出更复杂的结构。有趣的是，我们没有发现开花位点C（FLC）的同源物，FLC是一种作为花抑制因子且受低温负调控的转录因子。这一结果为先前的一项研究提供了分子解释，该研究表明春化不是啤酒花开花的必要条件，这对其在热带地区的种植具有重要意义。基因本体分析和表达谱分析揭示了基于花的每个轮中ABC同源异型基因的差异表达而可能参与雄花和雌花结构发育的基因。我们鉴定出一个仅在啤酒花腺毛中表达的基因，表明其在这些结构的特殊代谢中发挥作用。这项工作有助于理解啤酒花中MADS盒基因的进化历史，并为功能基因研究、生物技术和作物育种提供了思路。
