Low temperature is an important limiting factor in the environment that affects the distribution, growth and development of warm-season grasses. Transcriptome sequencing has been widely used to mine candidate genes under low-temperature stress and other abiotic stresses. However, the molecular mechanism of centipedegrass in response to low-temperature stress was rarely reported. To understand the molecular mechanism of centipedegrass in response to low-temperature stress, we measured physiological indicators and sequenced the transcriptome of centipedegrass under different stress durations. Under cold stress, the SS content and APX activity of centipedegrass increased while the SOD activity decreased; the CAT activity, POD activity and flavonoid content first increased and then decreased; and the GSH-Px activity first decreased and then increased. Using full-length transcriptome and second-generation sequencing, we obtained 38.76 G subreads. These reads were integrated into 177,178 isoforms, and 885 differentially expressed transcripts were obtained. The expression of AUX_IAA and WRKY transcription factors and HSF transcription-influencing factors increased during cold stress. Through KEGG enrichment analysis, we determined that arginine and proline metabolism, plant circadian rhythm, plant hormone signal transduction and the flavonoid biosynthesis pathways played important roles in the cold stress resistance of centipedegrass. In addition, by using weighted gene coexpression network analysis (WGCNA), we determined that the turquoise module was significantly correlated with SS content and APX activity, while the blue module was significantly negatively correlated with POD and CAT activity. This paper is the first to report the response of centipedegrass to cold stress at the transcriptome level. Our results help to clarify the molecular mechanisms underlying the cold tolerance of warm-season grasses.

Soil salinization is a significant obstacle to improving natural grasslands, also affecting farmland productivity. The main distribution area of high salinity soils is primarily located in western China, with a significant presence in the Qinghai–Tibet Plateau (QTP). Siberian wildrye (Elymus sibiricus L.) has been widely used in ecological restoration and reseeding in the QTP, due to its strong salt and alkali resistance. To comprehensively evaluate its salt tolerance and to screen salt-tolerant and salt-sensitive germplasm resources, 50 wild E. sibiricus accessions were assessed through the measurement of several physiological parameters. These included the relative water content (RWC); relative electrical conductivity (REC); malondialdehyde content (MDA); proline content (Pro); and Na⁺/K⁺ ratio after 14 days of salt stress treatment (200 mmol L⁻¹ NaCl). Through principal component analysis (PCA) based on both material sources and physiological indexing, it was found that the salt damage score (SDS) and RWC had a strong positive correlation (p < 0.05), in opposition to other indices. The positive indicators were REC, Pro, Na⁺/K⁺, and MDA, and the negative indicators were RWC and SDS. Ultimately, by combining the results of the conventional membership function analysis and the weighted membership function analysis based on major components, three salt-tolerant accessions—including XJ013-28, NM021-13 and XJ012-17—and four salt-sensitive accessions, including XZ008-20, QH013-8, XZ009-20, and QH005-35, were screened out. These results could be effectively used to assess the effects of salt stress on Siberian wildrye and its related species. This study provides a reference for the discovery and breeding of salt-tolerant cultivars among the Elymus species.

Siberian wildrye (Elymus sibiricus L.), a model Elymus Gramineae plant, has high eco-economic value but limited seed and forage yield. TCP transcription factors are widely regarded as influencing yield and quality and being crucial for growth and development; still, this gene family in Siberian wildrye remains unexplored. Therefore, this study looked at the Siberian wildrye TCP gene family’s reaction to several abiotic stresses, its expression pattern, and its potential evolutionary path. Fifty-four members of the EsTCP gene family were discovered. There are two major subfamilies based on the phylogenetic tree: 27 of Class I (PCF) and 27 of Class II (12 CIN-type and 15 TB1/CYC-type). Gene structure, conserved motif, and sequence alignment analyses further validated this classification. Cis-elements found in the promoter region of EsTCPs are associated with lots of plant hormones and stress-related reactions, covering drought induction and cold tolerance. EsCYC5, EsCYC6, and EsCYC7 may regulate tillering and lateral branch development. EsPCF10’s relative expression was significant under five stresses. Additionally, eight EsTCP genes are potential miR319 targets. These findings highlight the critical significance of the TCP gene family in Siberian wildrye, laying the groundwork for understanding the function of the EsTCP protein in abiotic stress studies and high-yield breeding.