The first high-altitude autotetraploid haplotype-resolved genome assembled (Rhododendron nivale subsp. boreale) provides new insights into mountaintop adaptation

GigaScience, Journal Year: 2024, Volume and Issue: 13

Published: Jan. 1, 2024

Abstract Background Rhododendron nivale subsp. boreale Philipson et M. N. is an alpine woody species with ornamental qualities that serve as the predominant in mountainous scrub habitats found at altitude of ∼4,200 m. As a high-altitude polyploid, this may model to understand how plants adapt environments. Despite its ecological significance, lack genomic resources has hindered comprehensive understanding evolutionary and adaptive characteristics Findings We sequenced assembled genome R. boreale, assembly first subgenus flowering tetraploid, contributing important resource for flora. The included 52 pseudochromosomes (scaffold N50 = 42.93 Mb; BUSCO 98.8%; QV 45.51; S-AQI 98.69), which belonged 4 haplotypes, harboring 127,810 predicted protein-coding genes. Conjoint k-mer analysis, collinearity assessment, phylogenetic investigation corroborated autotetraploid identity. Comparative analysis revealed originated neopolyploid underwent 2 rounds ancient polyploidy events. Transcriptional expression showed differences between alleles were common randomly distributed genome. identified extended gene families signatures positive selection are involved not only adaptation mountaintop ecosystem (response stress developmental regulation) but also reproduction (meiotic stabilization). Additionally, levels (group VII ethylene response factor transcription factors) ERF VIIs significantly higher than mean global expression. suspect these changes have enabled success high altitudes. Conclusions autopolyploid achieved chromosome-level within Rhododendron. In addition, strategy was reasonably speculated. This study provides valuable data exploration adaptations correlation extreme environments polyploidization.

Language: Английский

Expression patterns of Arabidopsis thaliana RecQ-like (AtRecQl) genes and the roles of AtRecQl2 and AtRecQl3 in response to abiotic stress

Bioscience Biotechnology and Biochemistry, Journal Year: 2024, Volume and Issue: 88(12), P. 1411 - 1423

Published: Sept. 25, 2024

Helicases are involved in almost every nucleic acid metabolism process. Within this family, RecQ helicase proteins protect genome integrity across all organisms through DNA recombination, repair, and replication. This study focused on five Arabidopsis thaliana RecQ-like (AtRecQl) genes with diverse functionalities. Analysis of ProAtRecQl: GUS expression during vegetative reproductive development stages revealed organ- tissue-specific patterns. Changes AtRecQls transcript levels response to abiotic stressors suggest their involvement stimuli responses. Notably, germination growth rates were lower atrecql2 atrecql3 mutants under various salt concentrations cold conditions. These findings indicate that AtRecQl2 AtRecQl3 act as positive regulators stress tolerance the germinative postgerminative phases.

Language: Английский