Abstract：
Suaeda salsa L. is a typical halophyte with high value as a vegetable. Here, we report a 447.98 Mb, chromosomal-level genome of S. salsa, assembled into nine pseudomolecules (contig N50 = 1.36 Mb) and annotated with 27,927 annotated protein-coding genes. Most of the assembled S. salsa genome, 58.03%, consists of transposable elements. Some gene families including HKT1, NHX, SOS and CASP related to salt resistance were significantly amplified. We also observed expansion of genes encoding protein that bind the trace elements Zn, Fe, Cu and Mn, and genes related to flavonoid and α-linolenic acid metabolism. Many expanded genes were significantly up-regulated under salinity, which might have contributed to the acquisition of salt tolerance in S. salsa. Transcriptomic data showed that high salinity markedly up-regulated salt-resistance related genes, compared to low salinity. Abundant metabolic pathways of secondary metabolites including flavonoid, unsaturated fatty acids and selenocompound were enriched, which indicates that the species is a nutrient-rich vegetable. Particularly worth mentioning is that there was no significant difference in the numbers of cis-elements in the promoters of salt-related and randomly selected genes in S. salsa when compared with Arabidopsis thaliana, which may affirm that plant salt tolerance is a quantitative rather than a qualitative trait in terms of promoter evolution. Our findings provide deep insight into the adaptation of halophytes to salinity from a genetic evolution perspective.
摘要：
盐田碱蓬是一种典型的盐生植物，具有很高的蔬菜价值。这里,我们报告了447.98Mb，沙门氏菌的染色体水平基因组，组装成9个假分子（重叠群N50=1.36Mb），并用27,927个注释的蛋白质编码基因进行注释。大多数组装好的莎莎酵母基因组，58.03%,由转座元素组成。一些基因家族包括HKT1，NHX，与耐盐性有关的SOS和CASP显著扩增。我们还观察到编码与微量元素Zn结合的蛋白质的基因的扩展，Fe,Cu和Mn,以及与类黄酮和α-亚麻酸代谢相关的基因。许多扩增的基因在盐度下显著上调,这可能有助于获得S.salsa的耐盐性。转录组数据显示，高盐度显著上调耐盐相关基因，与低盐度相比。丰富的代谢途径的次级代谢产物，包括类黄酮，富含不饱和脂肪酸和硒化合物，这表明该物种是营养丰富的蔬菜。特别值得一提的是，与拟南芥相比，盐相关基因和随机选择基因的启动子中顺式元件的数量没有显着差异。这可以肯定植物耐盐性在启动子进化方面是定量的而不是定性的。我们的发现从遗传进化的角度为盐生植物对盐度的适应提供了深刻的见解。
