背景:伪黑属(Nevski)Löve(小麦,禾本科),其基因组符号被设计为“St”,占多年生小麦科物种的60%以上。二倍体物种狼尾草(2n=14)包含最古老的St基因组,表现出很强的抗旱性,并且在形态上被地上部分的角质层蜡覆盖。因此,St基因组测序数据可以为研究基因组进化提供基础信息,揭示其表皮蜡质和抗旱机制。
结果:在这项研究中,我们报道了PseSt基因组的染色体水平基因组组装。libanotica,总大小为2.99Gb。注释了46,369个蛋白质编码基因,其中71.62%是重复序列。比较分析显示,伪牙菌属在上世纪中晚期分化。在此期间,独特的基因,基因家族扩展,以及Pse的收缩。利比亚富含生物和非生物胁迫,如脂肪酸生物合成,这可能极大地有助于其适应干旱。此外,我们研究了与角质层蜡形成和水分亏缺相关的基因,并发现了一个新的Kcs基因evm。TU。CTG175.54.它在Pse中从C18到C26的极长链脂肪酸(VLCFA)延伸中起关键作用。利比亚。该功能需要更多的证据来验证。
结论:我们对小麦的St基因组进行了测序和组装,并发现了一个新的KCS基因,该基因在蜡延伸中发挥作用以应对干旱。我们的研究为小麦物种的基因组多样化奠定了基础,并破译了与抗旱有关的角质层蜡形成基因。
BACKGROUND: The genus Pseudoroegneria (Nevski) Löve (Triticeae, Poaceae), whose genome symbol was designed as \"St\", accounts for more than 60% of perennial Triticeae species. The diploid species Psudoroegneria libanotica (2n = 14) contains the most ancient St genome, exhibited strong drought resistance, and was morphologically covered by cuticular wax on the aerial part. Therefore, the St-genome sequencing data could provide fundamental information for studies of genome evolution and reveal its mechanisms of cuticular wax and drought resistance.
RESULTS: In this study, we reported the chromosome-level genome assembly for the St genome of Pse. libanotica, with a total size of 2.99 Gb. 46,369 protein-coding genes annotated and 71.62% was repeat sequences. Comparative analyses revealed that the genus Pseudoroegneria diverged during the middle and late Miocene. During this period, unique genes, gene family expansion, and contraction in Pse. libanotica were enriched in biotic and abiotic stresses, such as fatty acid biosynthesis which may greatly contribute to its drought adaption. Furthermore, we investigated genes associated with the cuticular wax formation and water deficit and found a new Kcs gene evm.TU.CTG175.54. It plays a critical role in the very long chain fatty acid (VLCFA) elongation from C18 to C26 in Pse. libanotica. The function needs more evidence to be verified.
CONCLUSIONS: We sequenced and assembled the St genome in Triticeae and discovered a new KCS gene that plays a role in wax extension to cope with drought. Our study lays a foundation for the genome diversification of Triticeae species and deciphers cuticular wax formation genes involved in drought resistance.