Abstract：
Water scarcity, resulting from climate change, poses a significant threat to ecosystems. Syntrichia ruralis, a dryland desiccation-tolerant moss, provides valuable insights into survival of water-limited conditions. We sequenced the genome of S. ruralis, conducted transcriptomic analyses, and performed comparative genomic and transcriptomic analyses with existing genomes and transcriptomes, including with the close relative S. caninervis. We took a genetic approach to characterize the role of an S. ruralis transcription factor, identified in transcriptomic analyses, in Arabidopsis thaliana. The genome was assembled into 12 chromosomes encompassing 21 169 protein-coding genes. Comparative analysis revealed copy number and transcript abundance differences in known desiccation-associated gene families, and highlighted genome-level variation among species that may reflect adaptation to different habitats. A significant number of abscisic acid (ABA)-responsive genes were found to be negatively regulated by a MYB transcription factor (MYB55) that was upstream of the S. ruralis ortholog of ABA-insensitive 3 (ABI3). We determined that this conserved MYB transcription factor, uncharacterized in Arabidopsis, acts as a negative regulator of an ABA-dependent stress response in Arabidopsis. The new genomic resources from this emerging model moss offer novel insights into how plants regulate their responses to water deprivation.
摘要：
缺水,由于气候变化，对生态系统构成重大威胁。神经合毛，一种耐旱地干燥的苔藓，提供了对水资源有限条件下生存的宝贵见解。我们对S.ruralis的基因组进行了测序，进行转录组学分析，并对现有的基因组和转录组进行了比较基因组和转录组分析，包括与近亲S.caninervis。我们采用了遗传学方法来表征S.ruralis转录因子的作用，在转录组学分析中确定，拟南芥。基因组组装成12条染色体，包含21169个蛋白质编码基因。比较分析显示已知干燥相关基因家族的拷贝数和转录物丰度差异，并强调了物种之间的基因组水平差异，这些差异可能反映了对不同栖息地的适应。发现大量脱落酸（ABA）响应基因受ABA不敏感3（ABI3）的南方沙棘直系同源上游的MYB转录因子（MYB55）负调控。我们确定这种保守的MYB转录因子，在拟南芥中没有特征，在拟南芥中充当ABA依赖性应激反应的负调节剂。来自这种新兴模型苔藓的新基因组资源为植物如何调节其对缺水的反应提供了新的见解。
