Departamento de Agronomia, Centro de Ciências Agrárias e Engenharias, Universidade Federal do Espírito Santo, Alto Universitário, s/n, Guararema, Alegre, ES, 29500-000, Brazil.
Departamento de Biologia Geral, Universidade Federal de Viçosa, Av. Peter Henry Rolfs, s/n, Campus Universitário, Viçosa, MG, 36570-900, Brazil.
Sci Rep. 2023 Jan 25;13(1):1385. doi: 10.1038/s41598-023-27912-w.
Diploid and polyploid species derived from the euploid series x = 11 occur in the genus Psidium, as well as intraspecific cytotypes. Euploidy in the genus can alter the gene copy number, resulting in several "omics" variations. We revisited the euploidy, reported genomic (nuclear 2C value, GC%, and copy number of secondary metabolism genes) and epigenomic (5-mC%) differences in Psidium, and related them to essential oil yield and composition. Mean 2C values ranged from 0.90 pg (P. guajava) to 7.40 pg (P. gaudichaudianum). 2C value is intraspecifically varied in P. cattleyanum and P. gaudichaudianum, evidencing cytotypes that can be formed from euploid (non-reduced) and/or aneuploid reproductive cells. GC% ranged from 34.33% (P. guineense) to 48.95% (P. myrtoides), and intraspecific variations occurred even for species without 2C value intraspecific variation. Essential oil yield increased in relation to 2C value and to GC%. We showed that P. guajava (diploid) possesses two and P. guineense (tetraploid) four copies of the one specific TPS gene, as well as eight and sixteen copies respectively of the conserved regions that occur in eight TPS genes. We provide a wide "omics'' characterization of Psidium and show the outcome of the genome and epigenome variation in secondary metabolism.
在蒲桃属中，除了存在多倍体和同源多倍体物种外，还存在整倍体系列 x = 11 的物种和种内细胞型。该属中的整倍性会改变基因拷贝数，导致多种“组学”变异。我们重新研究了蒲桃属中的整倍性，报道了基因组（核 2C 值、GC%和次生代谢基因拷贝数）和表观基因组（5-mC%）的差异，并将其与精油产量和组成相关联。平均 2C 值范围从 0.90 pg（番石榴）到 7.40 pg（古巴蒲桃）。在蒲桃和古巴蒲桃中，2C 值在种内存在差异，表明可以由整倍体（非减数分裂）和/或非整倍体生殖细胞形成细胞型。GC%范围从 34.33%（几内亚蒲桃）到 48.95%（密花蒲桃），即使在没有 2C 值种内变异的物种中也存在种内变异。精油产量与 2C 值和 GC%呈正相关。我们表明，二倍体番石榴（2n=2x=22）具有两个，四倍体几内亚蒲桃（2n=4x=44）具有四个特定的 TPS 基因的拷贝，以及在 8 个 TPS 基因中分别存在 8 个和 16 个保守区域的拷贝。我们对蒲桃属进行了广泛的“组学”表征，并展示了次生代谢中基因组和表观基因组变异的结果。
