Comparative transcriptomic analyses of two sugarcane Saccharum L. cultivars differing in drought tolerance

Sugarcane (Saccharum spp.) is an important cash crop, and drought is an important factors limiting its yield. To study the drought resistance mechanism of sugarcane, the transcriptomes of two sugarcane varieties with different levels of drought resistance were compared under different water shortage levels. The results showed that the transcriptomes of the two varieties were significantly different. The differentially expressed genes were enriched in starch and sucrose metabolism, linoleic acid metabolism, glycolysis/gluconeogenesis, and glyoxylate and dicarboxylate metabolic pathways. Unique trend genes of the variety with strong drought resistance (F172) were significantly enriched in photosynthesis, mitogen-activated protein kinases signaling pathway, biosynthesis of various plant secondary metabolites, and cyanoamino acid metabolism pathways. Weighted correlation network analysis indicated that the blue4 and plum1 modules correlated with drought conditions, whereas the tan and salmon4 modules correlated with variety. The unique trend genes expressed in F172 and mapped to the blue4 module were enriched in photosynthesis, purine metabolism, starch and sucrose metabolism, beta-alanine metabolism, photosynthesis-antenna proteins, and plant hormone signal transduction pathways. The expression of genes involved in the photosynthesis-antenna protein and photosynthesis pathways decreased in response to water deficit, indicating that reducing photosynthesis might be a means for sugarcane to respond to drought stress. The results of this study provide insights into drought resistance mechanisms in plants, and the related genes and metabolic pathways identified may be helpful for sugarcane breeding in the future

From Traditional to VR-Based Online Education Platforms: A Model of the Mechanism Influencing User Migration

VR technology can help create optimal virtual learning spaces. Such spaces offer new visual experiences that break through the limitations of time and space and greatly stimulate people’s imagination and creativity in learning. Currently, the bandwidth required for such spaces limits the large-scale application of virtual reality (VR) technology for this purpose. With the large-scale deployment and application of high-speed networks, however, online education platforms based on VR technology will be better able to meet the diversified and personalized learning needs of learners. To promote the development and popularization of new online education platforms based on VR, the factors influencing the migration of learners from traditional online education platforms to new platforms need to be understood more clearly. A model based on the theory of negative, positive, and anchoring effects can explain learners’ migration behavior in this connection. To this end, a structural equation model based on the PLS variance algorithm was used to analyze data obtained through offline and online questionnaires. It was found that in terms of “negative effects”, the afunction and loyalty associated with traditional online education platforms reduced learners’ willingness to migrate to new platforms based on VR technology. In terms of “positive effects”, the novel interactivity and personalization brought by the new platform increased the willingness of users of traditional platforms to migrate to new platforms. In terms of “anchoring effects”, the system quality and relationship quality of learners’ use of traditional online education platforms, as well as the transfer costs associated with the new platform, generated learners’ risk perception about platform migration. In addition, risk perception not only negatively affects learners’ migration to the new platforms, but also strengthens their cognition of the system quality and relationship quality of the traditional platforms, while reducing their interactive awareness of those platforms. Therefore, by adjusting the psychological component of virtual learning, the online education platforms based on VR technology can create high-quality platforms migrating from traditional platforms

Comprehensive transcriptome analysis reveals genes in response to water deficit in the leaves of Saccharum narenga (Nees ex Steud.) hack

Abstract Background Sugarcane is an important sugar and energy crop that is widely planted in the world. Among the environmental stresses, the water-deficit stress is the most limiting to plant productivity. Some groups have used PCR-based and microarray technologies to investigate the gene expression changes of multiple sugarcane cultivars under water stress. Our knowledge about sugarcane genes in response to water deficit is still poor. Results A wild sugarcane type, Saccharum narenga, was selected and treated with drought stress for 22 days. Leaves from drought treated (DTS) and control (CK) plants were obtained for deep sequencing. Paired-end sequencing enabled us to assemble 104,644 genes (N50 = 1605 bp), of which 38,721 were aligned to other databases, such as UniProt, NR, GO, KEGG and Pfam. Single-end and paired-end sequencing identified 30,297 genes (> 5 TPM) in all samples. Compared to CK, 3389 differentially expressed genes (DEGs) were identified in DTS samples, comprising 1772 up-regulated and 1617 down-regulated genes. Functional analysis showed that the DEGs were involved in biological pathways like response to blue light, metabolic pathways and plant hormone signal transduction. We further observed the expression patterns of several important gene families, including aquaporins, late embryogenesis abundant proteins, auxin related proteins, transcription factors (TFs), heat shock proteins, light harvesting chlorophyll a-b binding proteins, disease resistance proteins, and ribosomal proteins. Interestingly, the regulation of genes varied among different subfamilies of aquaporin and ribosomal proteins. In addition, DIVARICATA and heat stress TFs were first reported in sugarcane leaves in response to water deficit. Further, we showed potential miRNAs that might be involved in the regulation of gene changes in sugarcane leaves under the water-deficit stress. Conclusions This is the first transcriptome study of Saccharum narenga and the assembled genes are a valuable resource for future research. Our findings will improve the understanding of the mechanism of gene regulation in sugarcane leaves under the water-deficit stress. The output of this study will also contribute to the sugarcane breeding program

Comparative Transcriptome Analysis of Two Sugarcane Cultivars in Response to Paclobutrazol Treatment

Sugarcane is an important crop across the globe, and the rapid multiplication of excellent cultivars is an important object of the sugarcane industry. As one of the plant growth regulators, paclobutrazol (PBZ) has been frequently used in the tissue culture of sugarcane seedlings. However, little is known about the molecular mechanisms of response to PBZ in this crop. Here, we performed a comparative transcriptome analysis between sensitive (LC05−136) and non−sensitive (GGZ001) sugarcane cultivars treated by PBZ at three time points (0 d, 10 d, and 30 d) using RNA sequencing (RNA−Seq). The results showed that approximately 70.36 Mb of clean data for each sample were generated and assembled into 239,212 unigenes. A total of 6108 and 4404 differentially expressed genes (DEGs) were identified within the sensitive and non−sensitive sugarcane cultivars, respectively. Among them, DEGs in LC05−136 were most significantly enriched in the photosynthesis and valine, leucine and isoleucine degradation pathways, while in GGZ001, DEGs associated with ion channels and plant–pathogen interaction were mainly observed. Notably, many interesting genes, including those encoding putative regulators, key components of photosynthesis, amino acids degradation and glutamatergic synapse, were identified, revealing their importance in the response of sugarcane to PBZ. Furthermore, the expressions of sixteen selected DEGs were tested by quantitative reverse transcription PCR (RT−qPCR), confirming the reliability of the RNA−seq data used in this study. These results provide valuable information regarding the transcriptome changes in sugarcane treated by PBZ and provide an insight into understanding the molecular mechanisms underlying the resistance to PBZ in sugarcane

High-Performance Aqueous Zinc-Ion Batteries Enabled by Binder-Free and Ultrathin V₂O_5–<i>x</i>@Graphene Aerogels with Intercalation Pseudocapacitance

As a result of the absence of solid-state diffusion limitation, intercalation pseudocapacitance behavior is emerging as an attractive charge-storage mechanism that can greatly facilitate the ion kinetics to boost the rate capability and cycle stability of batteries; however, related research in the field of zinc-ion batteries (ZIBs) is still in the initial stage and only found in limited cathode materials. In this study, a novel V2O5–x@rGO hybrid aerogel consisting of ultrathin V2O5 nanosheets (∼1.26 nm) with abundant oxygen vacancies (Vö) and a three-dimensional (3D) graphene conductive network was specifically designed and used as a freestanding and binder-free electrode for ZIBs. As expected, the ideal microstructure of both the material and the electrode enable fast electron/ion diffusion kinetics of the electrode, which realize a typical intercalation pseudocapacitance behavior as demonstrated by the simulation calculation of cyclic voltammetry (CV), ex situ X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and first-principles density functional theory (DFT) calculation. Thanks to the elimination of solid-state diffusion limitation, the V2O5–x@rGO electrode delivers a high reversible rate capacity of 153.9 mAh g–1 at 15 A g–1 and 90.6% initial capacity retention at 0.5 A g–1 after 1050 cycles in ZIBs. The intercalation pseudocapacitance behavior is also realized in the assembled soft-pack battery, showing promising practical application prospects