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.

Glaciation and mountain orogeny have generated new ecologic opportunities for plants, favoring an increase in the speciation rate. Moreover, they also act as corridors or barriers for plant lineages and populations. High genetic diversity ensures that species are able to survive and adapt. Gene flow is one of the most important determinants of the genetic diversity and structure of out-crossed species, and it is easily affected by biotic and abiotic factors. The aim of this study was to characterize the genetic diversity and structure of an alpine species, Festuca ovina L., in Xinjiang, China. A total of 100 individuals from 10 populations were analyzed using six amplified fragment length polymorphism (AFLP) primer pairs. A total of 583 clear bands were generated, of which 392 were polymorphic; thus, the percentage of polymorphic bands (PPB) was 67.24%. The total and average genetic diversities were 0.2722 and 0.2006 (0.1686–0.2225), respectively. The unweighted group method with arithmetic mean (UPGMA) tree, principal coordinates analysis (PCoA) and Structure analyses revealed that these populations or individuals could be clustered into two groups. The analysis of molecular variance analysis (AMOVA) suggested that most of the genetic variance existed within a population, and the genetic differentiation (Fst) among populations was 20.71%. The Shannon differentiation coefficient (G’st) among populations was 0.2350. Limited gene flow (Nm = 0.9571) was detected across all sampling sites. The Fst and Nm presented at different levels under the genetic barriers due to fragmentation. The population genetic diversity was significant relative to environmental factors such as temperature, altitude and precipitation.

Reed canary grass (Phalaris arundinacea L.) is known for its tolerance to drought, heavy metals, and waterlogging, making it a popular choice for forage production and wetland restoration in the Qinghai-Tibet Plateau (QTP). To accurately assess gene expression in reed canary grass under different abiotic stresses, suitable reference genes need to be identified and validated. Thirteen candidate reference gene sequences were selected and screened using RT-qPCR to detect their expression levels in reed canary grass leaves under drought, salt, cadmium, and waterlogging stresses. Four algorithms were used to assess the stability of the expression levels of the candidate reference genes. The most stably expressed genes were UBC and H3 under drought Cd, ETF and CYT under salt stress, and ETF and TUB under waterlogging stress. GAPDH was found to be less stable under abiotic stresses. PIP-1, PAL, NAC 90, and WRKY 72A were selected as response genes for quantitative expression assessment under drought, salt, Cd, and waterlogging stresses to confirm the accuracy of the selected stable reference genes. These results provide a theoretical reference for assessing gene expression in reed canary grass under abiotic stresses.

As a C4 warm-season turfgrass, centipedegrass (Eremochloa ophiuroides (Munro) Hack.) is known for its exceptional resilience to intensive maintenance practices. In this research, the most stably expressed reference genes in the leaves of centipedegrass under different stress treatments, including salt, cold, drought, aluminum (Al), and herbicide, were screened by the quantitative real-time PCR (RT-qPCR) technique. The stability of 13 candidate reference genes was evaluated by software GeNorm V3.4, NormFinder V20, BestKeeper V1.0, and ReFinder V1.0. The results of this experiment demonstrated that the expression of the UBC (ubiquitin-conjugating enzyme) remained the most stable under cold and Al stress conditions. On the other hand, the MD (malate dehydrogenase) gene exhibited the best performance in leaf tissues subjected to salt and drought stresses. Under herbicide stress, the expression level of the RIP (60S ribosomal protein L2) gene ranked the highest. The expression levels of abiotic stress-associated genes such as PIP1, PAL, COR413, ALMT9, and BAR were assessed to validate the reliability of the selected reference genes. This study provides valuable information and reference points for gene expression under abiotic stress conditions in centipedegrass.

Six varieties of Erianthus arundinaceus were assessed as potential energy crops and compared with switchgrass. Bioethanol and biomethane were produced as well. The chemical composition, elemental composition, and heating values were close to those of switchgrass except for a higher cellulose content. All varieties scored higher than 110, suggesting excellent potential as an energy crop. Pretreatment resulted in almost complete hydrolysis and achieved a higher glucose yield. In particular, E33 and E19 yielded 337.4 g and 332.4 g glucose, respectively, from 1.0 kg of feedstock compared with 312.1g/kg for switchgrass. E33, E49, and E19 exhibited a higher ethanol yield of 144.2 g/kg, 146.9 g/kg, and 149.6 g/kg feedstock, respectively, at a solids loading of 15%. No obvious influences could be observed on anaerobic digestion performances. A 16.3%, 14.6%, 14.0%, and 13.1% higher yield on cumulative methane could be obtained from E17, E23, E33, and E6, respectively, compared to switchgrass. Bioethanol and biomethane could be maximally obtained from E19 (6820 kg/ha) and E17 (3916 m3/ha), respectively. Thus, they are specially recommended for bioethanol and biomethane production, respectively. E33 can be suggested as a flexible variety for yielding relatively high bioethanol (6008 kg/ha) and biomethane (3409 m3/ha).

Reed canary grass (Phalaris arundinacea L.) is a promising high-yield cool-season forage with significant ecological application potential in wastewater treatment and wetland restoration. Transcriptome sequences can rapidly assay and characterize a few gene-based microsatellites from various plants. Here, the transcriptome of reed canary grass was sequenced, and 50,155 putative EST-SSRs were identified from 272,328 transcripts, with tri-nucleotide being the most abundant type, followed by mono-nucleotide. A total of 300 EST-SSR markers were randomly selected, among which 45 polymorphic EST-SSR markers were used for the genetic diversity study of 17 reed canary grass accessions (P. arundinacea L.) and 2 accessions of related bulbous canary grass (P. aquatica L.). A total of 218 bands were amplified using 45 SSR markers; the reliable polymorphic bands were 118 (54.13%), the average of the polymorphic information content was 0.36, and the RP value was 0.96. In summary, the transcriptome sequences of reed canary grass contribute to gene prediction and promote molecular biology and genomics studies, whereas polymorphic SSR markers promote molecular-assisted breeding and related studies of Phalaris species.