Combined genome and transcriptome analysis of elite fiber quality in Gossypium barbadense.

Gossypium barbadense, which is one of several species of cotton, is well known for its superior fiber quality. However, the genetic basis of its high-quality fiber remains largely unexplored. Here, we resequenced 269 G. barbadense accessions. Phylogenetic structure analysis showed that the set of accessions was clustered into 3 groups: G1 and G2 mainly included modern cultivars from Xinjiang, China, and G3 was related to widely introduced accessions in different regions worldwide. A genome-wide association study of 5 fiber quality traits across multiple field environments identified a total of 512 qtls (main-effect QTLs) and 94 qtlEs (QTL-by-environment interactions) related to fiber quality, of which 292 qtls and 57 qtlEs colocated with previous studies. We extracted the genes located in these loci and performed expression comparison, local association analysis, and introgression segment identification. The results showed that high expression of hormone-related genes during fiber development, introgressions from Gossypium hirsutum, and the recombination of domesticated elite allelic variation were 3 major contributors to improve the fiber quality of G. barbadense. In total, 839 candidate genes with encoding region variations associated with elite fiber quality were mined. We confirmed that haplotype GB_D03G0092H traced to G. hirsutum introgression, with a 1-bp deletion leading to a frameshift mutation compared with GB_D03G0092B, significantly improved fiber quality. GB_D03G0092H is localized in the plasma membrane, while GB_D03G0092B is in both the nucleus and plasma membrane. Overexpression of GB_D03G0092H in Arabidopsis (Arabidopsis thaliana) significantly improved the elongation of longitudinal cells. Our study systematically reveals the genetic basis of the superior fiber quality of G. barbadense and provides elite segments and gene resources for breeding high-quality cotton cultivars.

Enhancement of spinal dorsal horn neuron NMDA receptor phosphorylation as the mechanism of remifentanil induced hyperalgesia: Roles of PKC and CaMKII.

Background: Modulation of N-methyl-D-aspartate receptor subunits NR1 and NR2 through phosphorylation mediates opioid-induced hyperalgesia, and activations of protein kinase C and extracellular signal-regulated kinase 1/2 potentiate while activation of calcium/calmodulin-dependent protein kinase II inhibits opioid-induced hyperalgesia. However, the mechanism of opioid-induced hyperalgesia development and in particular the potential interplay between N-methyl-D-aspartate receptors and protein kinase C or calcium/calmodulin-dependent protein kinase II or extracellular signal-regulated kinase 1/2 in the development of remifentanil-induced hyperalgesia is unclear. Methods: Remifentanil (1 µg c kg−1 c min−1) was given intravenously over 60 min in rats, followed by the infusion of either vehicle solution or the respective inhibitors of protein kinase C (chelerythrine), extracellular signal-regulated kinase II (KN93), or extracellular signal-regulated kinase 1/2 (PD98059). Thereafter, the pain behaviors were evaluated by the paw withdrawal mechanical threshold and paw withdrawal thermal latency. In in vitro studies, fetal spinal cord dorsal horn neurons were primary cultured in the presence of 4 nM remifentanil for 60 min, and then the remifentanil was washed out and replaced immediately by culturing in the absence or presence of chelerythrine, KN93 or PD98059, respectively for up to 8 h. The expressions of N-methyl-D-aspartate receptors subunits and their phosphorylation (NR1, NR2B, p-NR1, p-NR2B) were analyzed by Western blotting after the completion of treatments. Functional changes of N-methyl-D-aspartate receptors were evaluated by electrophysiologic recordings of N-methyl-D-aspartate currents. Results: Remifentanil induced significant thermal and mechanical hyperalgesia, which were significantly attenuated by Chelerythrine or KN93 but not PD98059. The expressions of NR1, NR2B, p-NR1, and p-NR2B were increased significantly and progressively over time after remifentanil administration, and these increases were all significantly attenuated by either chelerythrine or KN93 but not PD98059. Intriguingly, N-methyl-D-aspartate receptor functional enhancement induced by remifentanil was attenuated by Chelerythrine, KN93, and PD98059. Conclusions: It is concluded that the enhancements in function and quantity of N-methyl-D-aspartate receptor via phosphorylation of its subunits through protein kinase C and calcium/calmodulin-dependent protein kinase II activation may represent the major mechanism whereby remifentanil induced hyperalgesia.

Role of traditional Chinese medicine in age-related macular degeneration: exploring the gut microbiota's influence.

The pathogenesis of age-related macular degeneration (AMD), a degenerative retinopathy, remains unclear. Administration of anti-vascular endothelial growth factor agents, antioxidants, fundus lasers, photodynamic therapy, and transpupillary warming has proven effective in alleviating symptoms; however, these interventions cannot prevent or reverse AMD. Increasing evidence suggests that AMD risk is linked to changes in the composition, abundance, and diversity of the gut microbiota (GM). Activation of multiple signaling pathways by GM metabolites, including lipopolysaccharides, oxysterols, short-chain fatty acids (SCFAs), and bile acids (BAs), influences retinal physiology. Traditional Chinese medicine (TCM), known for its multi-component and multi-target advantages, can help treat AMD by altering GM composition and regulating the levels of certain substances, such as lipopolysaccharides, reducing oxysterols, and increasing SCFA and BA contents. This review explores the correlation between GM and AMD and interventions for the two to provide new perspectives on treating AMD with TCM.

Potential application of traditional Chinese medicine in age-related macular degeneration-focusing on mitophagy.

Retinal pigment epithelial cell and neuroretinal damage in age-related macular degeneration (AMD) can lead to serious visual impairments and blindness. Studies have shown that mitophagy, a highly specialized cellular degradation system, is implicated in the pathogenesis of AMD. Mitophagy selectively eliminates impaired or non-functioning mitochondria via several pathways, such as the phosphatase and tensin homolog-induced kinase 1/Parkin, BCL2-interacting protein 3 and NIP3-like protein X, FUN14 domain-containing 1, and AMP-activated protein kinase pathways. This has a major impact on the maintenance of mitochondrial homeostasis. Therefore, the regulation of mitophagy could be a promising therapeutic strategy for AMD. Traditional Chinese medicine (TCM) uses natural products that could potentially prevent and treat various diseases, such as AMD. This review aims to summarize recent findings on mitophagy regulation pathways and the latest progress in AMD treatment targeting mitophagy, emphasizing methods involving TCM.

An Easy and Rapid Transformation Protocol for Transient Expression in Cotton Fiber.

Cotton fiber is the most important natural textile material in the world. Identification and functional characterization of genes regulating fiber development are fundamental for improving fiber quality and yield. However, stable cotton transformation is time-consuming, low in efficiency, and technically complex. Moreover, heterologous systems, such as Arabidopsis and tobacco, did not always work to elucidate the function of cotton fiber specifically expressed genes or their promoters. For these reasons, constructing a rapid transformation system using cotton fibers is necessary to study fiber's specifically expressed genes. In this study, we developed an easy and rapid Agrobacterium-mediated method for the transient transformation of genes and promoters in cotton fibers. First, we found that exogenous genes could be expressed in cotton fibers via using ß-glucuronidase (GUS) and green fluorescence protein (GFP) as reporters. Second, parameters affecting transformation efficiency, including LBA4404 Agrobacterium strain, 3 h infection time, and 2-day incubation time, were determined. Third, four different cotton genes that are specifically expressed in fibers were transiently transformed in cotton fibers, and the transcripts of these genes were detected ten to thousand times increase over the control. Fourth, GUS staining and activity analysis demonstrated that the activity profiles of GhMYB212 and GhFSN1 promoters in transformed fibers are similar to their native activity in developmental fibers. Furthermore, the transient transformation method was confirmed to be suitable for subcellular localization studies. In summary, the presented Agrobacterium-mediated transient transformation method is a fast, simple, and effective system for promoter characterization and protein expression in cotton fibers.

GhRabA4c coordinates cell elongation via regulating actin filament-dependent vesicle transport.

Plant cell expands via a tip growth or diffuse growth mode. In plants, RabA is the largest group of Rab GTPases that regulate vesicle trafficking. The functions of RabA protein in modulating polarized expansion in tip growth cells have been demonstrated. However, whether and how RabA protein functions in diffuse growth plant cells have never been explored. Here, we addressed this question by examining the role of GhRabA4c in cotton fibers. GhRabA4c was preferentially expressed in elongating fibers with its protein localized to endoplasmic reticulum and Golgi apparatus. Over- and down-expression of GhRabA4c in cotton lead to longer and shorter fibers, respectively. GhRabA4c interacted with GhACT4 to promote the assembly of actin filament to facilitate vesicle transport for cell wall synthesis. Consistently, GhRabA4c-overexpressed fibers exhibited increased content of wall components and the transcript levels of the genes responsible for the synthesis of cell wall materials. We further identified two MYB proteins that directly regulate the transcription of GhRabA4c Collectively, our data showed that GhRabA4c promotes diffused cell expansion by supporting vesicle trafficking and cell wall synthesis.

A cotton NAC transcription factor GhirNAC2 plays positive roles in drought tolerance via regulating ABA biosynthesis.

NAC protein is a large plant specific transcription factor family, which plays important roles in the response to abiotic stresses. However, the regulation mechanism of most NAC proteins in drought stress remains to be further uncovered. In this study, we elucidated the molecular functions of a NAC protein, GhirNAC2, in response to drought stress in cotton. GhirNAC2 was greatly induced by drought and phytohormone abscisic acid (ABA). Subcellular localization demonstrated that GhirNAC2 was located in the nucleus. Co-suppression of GhirNAC2 in cotton led to larger stomata aperture, elevated water loss and finally reduced transgenic plants tolerance to drought stress. Furthermore, the endogenous ABA content was significantly lower in GhirNAC2-suppressed transgenic plant leaves compared to wild type. in vivo and in vitro studies showed that GhirNAC2 directly binds to the promoter of GhNCED3a/3c, key genes in ABA biosynthesis, which were both down-regulated in GhirNAC2-suppressed transgenic lines. Transient silencing of GhNCED3a/3c also significantly reduced the resistance to drought stress in cotton plants. However, ectopic expression of GhirNAC2 in tobacco significantly enhanced seed germination, root growth and plant survival under drought stress. Taken together, GhirNAC2 plays a positive role in cotton drought tolerance, which functions by modulating ABA biosynthesis and stomata closure via regulating GhNCED3a/3c expression.

Integration analysis of MKK and MAPK family members highlights potential MAPK signaling modules in cotton.

Mitogen-activated protein kinase (MAPK) cascades play a crucial role in plant growth and development, as well as their biotic and abiotic stress responses. As a nodal point of the MAPK cascade, the MKK gene family has not been systematically studied in cotton. Here, we identified 11 putative MKK genes in the Gossypium raimondii genome. Phylogenetic analysis showed that the MKKs were supported by architectures of conserved protein motifs. Expression patterns of MKKs under hormone treatments or abiotic stresses revealed their diverse functions in stress responses. Based on a yeast two hybrid, a total of 63 interactive pairs of MKKs and MAPKs were identified in cotton. Among these, 40 interactive pairs were newly identified compared to that reported previously in Arabidopsis. Integration analysis of the interaction network and expression patterns of MKK and MAPK family members revealed 13 potential MAPK signaling modules that are involved in the complicated cross-talk between hormones and abiotic stresses. Taken together, our data enhance the understanding of the evolution and function of MAPK cascades in cotton, and lay the foundation for the improvement of various defense responses that use MAPK signaling modules in the future.