Transcriptomic Analysis of Three Differentially Senescing Maize (Zea mays L.) Inbred Lines upon Heat Stress.

Maize, one of the world's major food crops, is facing the challenge of rising temperature. Leaf senescence is the most significant phenotypic change of maize under heat stress at the seedling stage, but the underlying molecular mechanism is still unknown. Here, we screened for three inbred lines (PH4CV, B73, and SH19B) that showed differentially senescing phenotypes under heat stress. Among them, PH4CV showed no obviously senescing phenotype under heat stress, while SH19B demonstrated a severely senescing phenotype, with B73 being between the two extremes. Subsequently, transcriptome sequencing showed that differentially expressed genes (DEGs) were generally enriched in response to heat stress, reactive oxygen species (ROS), and photosynthesis in the three inbred lines under heat treatment. Notably, ATP synthesis and oxidative phosphorylation pathway genes were only significantly enriched in SH19B. Then, the expression differences of oxidative phosphorylation pathways, antioxidant enzymes, and senescence-related genes in response to heat stress were analyzed in the three inbred lines. In addition, we demonstrated that silencing ZmbHLH51 by virus-induced gene silencing (VIGS) inhibits the heat-stress-induced senescence of maize leaves. This study helps to further elucidate the molecular mechanisms of heat-stress-induced leaf senescence at the seedling stage of maize.

Equity in walking access to community home care facility resources for elderly with different mobility: A case study of Lianhu District, Xi'an.

As the aging of China's population continues to deepen, a number of elderly care facilities relying on community platforms to provide home care services have been established in urban communities, effectively alleviating the problem of difficult community elderly care, while a spatial mismatch between the facilities and the elderly population has also emerged. To solve this problem, this paper analyzes the equity in walking access to community home care facilities for elderly people with different mobility abilities in Lianhu District of Xi'an City, taking the resources of community home care facilities as the research object. Firstly, the coverage rate of the facilities was calculated based on the 15-minute walking range of the elderly with different mobility, and the accessibility of the facilities was measured using the Kernel Density-type two-step moving search method. Then, Gini coefficient, Lorenz curve and location entropy were used to analyze the spatial matching pattern of facilities and elderly population. The results show that there is a serious spatial mismatch between the resources of community home care facilities and the elderly population with mobility restriction. In addition, the available facility area per capita is low for more than 80% of the elderly with mobility restriction, and the road network density has a significant impact on the access of the elderly with mobility restriction to the community home care facility resources. These research results indicate that the spatial layout and configuration of community home care facilities are unfair to the elderly with poor mobility, and that these elderly care facility configurations do not favor the disadvantaged groups.

Research on the coordination mechanism of major industrial project engineering and construction multi-agents based on structural holes theory.

Industry is an important pillar of the national economy. Industrial projects are the most complex and difficult projects to control in the construction industry, and major industrial projects are even more complex and difficult to control. Multi-agent coordination is one of the core issues of industrial projects. Based on an analysis of the engineering and construction chains and agent relationships and agent networks of industrial projects, a complex network of the engineering and construction agents of industrial projects is established, and the complex network structural holes theory is applied to study the nonrepeated relationships among agents in industrial projects. Assuming agents are linked through contract relations and the most critical contract index between the agents in the contract amount, through structural hole analysis considering the EPC and PMC model, the aggregate constraint list is obtained, 2D network diagram and 3D network diagram are shown. According to the aggregate constraint value, the EPC contractor with the minimum aggregate constraint value and the project management company with the minimum aggregate constraint value are the critical agent in EPC and PMC model. By analyzing the complex network comprising different models of industrial projects, it is concluded that the characteristics of the agent maintain an advantage in competition, the coordination mechanism of the integration of agent interests, and multi-agent relations are considered to solve the multi-agent coordination problem in major industrial projects.

OsPDCD5 negatively regulates plant architecture and grain yield in rice.

Plant architecture is an important agronomic trait that affects crop yield. Here, we report that a gene involved in programmed cell death, OsPDCD5, negatively regulates plant architecture and grain yield in rice. We used the CRISPR/Cas9 system to introduce loss-of-function mutations into OsPDCD5 in 11 rice cultivars. Targeted mutagenesis of OsPDCD5 enhanced grain yield and improved plant architecture by increasing plant height and optimizing panicle type and grain shape. Transcriptome analysis showed that OsPDCD5 knockout affected auxin biosynthesis, as well as the gibberellin and cytokinin biosynthesis and signaling pathways. OsPDCD5 interacted directly with OsAGAP, and OsAGAP positively regulated plant architecture and grain yield in rice. Collectively, these findings demonstrate that OsPDCD5 is a promising candidate gene for breeding super rice cultivars with increased yield potential and superior quality.

Identification, molecular characterization and expression of JAZ genes in Lycoris aurea.

Jasmonates (JAs) are key phytohormones involved in regulation of plant growth and development, stress responses, and secondary metabolism. It has been reported that treatments with JAs could increase the contents of Amaryllidaceae alkaloids in Amaryllidaceae plants. Jasmonate ZIM (zinc-finger inflorescence meristem) domain (JAZ) proteins are key components in JA signal processes. However, JAZ proteins have not been characterized in genus Lycoris. In this study, we identified and cloned seven differentially expressed JAZ genes (namely LaJAZ1-LaJAZ7) from Lycoris aurea. Bioinformatic analyses revealed that these seven LaJAZ proteins contain the ZIM domain and JA-associated (Jas, also named CCT_2) motif. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) analysis revealed that these LaJAZ genes display different expression patterns in L. aurea tissues, and most of them are inducible when treated with methyl jasmonate (MeJA) treatment. Subcellular localization assay demonstrated that LaJAZ proteins are localized in the cell nucleus or cytoplasm. In addition, LaJAZ proteins could interact with each other to form homodimer and/or heterodimer. The findings in this study may facilitate further functional research of the LaJAZ genes, especially the potential regulatory mechanism of plant secondary metabolites including Amaryllidaceae alkaloids in L. aurea.

Cloning and characterization of a tyrosine decarboxylase involved in the biosynthesis of galanthamine in Lycoris aurea.

BACKGROUND: Galanthamine, one kind of Amaryllidaceae alkaloid extracted from the Lycoris species, is used in the treatment of Alzheimer's disease. In regards to medical and economic importance, the biosynthesis and regulatory mechanism of the secondary metabolites in Lycoris remain uninvestigated. METHODS: BLAST was used to identify the sequence of tyrosine decarboxylase in the transcriptome of Lycoris aurea (L'Hér) Herb. The enzyme activity of this TYDC was determined by using heterologous expressed protein in the Escherichia coli cells. The related productive contents of tyramine were detected using High Performance Liquid Chromatography (HPLC). According to the available micro RNA sequencing profiles and degradome database of L. aurea, microRNA396 were isolated, which targets to LaTYDC1 and RNA Ligase-Mediated-Rapid Amplification of cDNA Ends (RLM-RACE) were used to confirm the cleavage. The expression levels of miR396 and LaTYDC1 were measured using a quantitative real-time polymerase chain reaction (qRT-PCR). RESULTS: LaTYDC1 was mainly expressed in root, bulb, leaf and flower fitting the models for galanthamine accumulation. This decarboxylase efficiently catalyzes tyrosine to tyramine conversion. Under methyl jasmonate (MeJA) treatment, the expression of LaTYDC1 and the content of tyramine sharply increase. The use of RLM-RACE confirms that miR396 promotes the degradation of LaTYDC1 mRNA. Under MeJA treatment, the expression of miR396 was suppressed while the expression level of LaTYDC1 sharply increased. Following the increase of the miR396 transcriptional level, LaTYDC1 was significantly repressed. CONCLUSION: LaTYDC1 participates in the biosynthesis of galanthamine, and is regulated by miR396. This finding also provides genetic strategy for improving the yield of galanthamine in the future.

Receptor mediation and nociceptin inhibition of bradykinin-induced plasma extravasation in the knee joint of the rat.

OBJECTIVE AND DESIGN: The aim was to investigate the signaling mechanisms and regulation of bradykinin (BK)-induced inflammation in rat knee joint. MATERIALS AND METHODS: Knee joints of anesthetized rats were perfused with BK (0.1-1.0 microM), and synovial plasma extravasation (PE) was evaluated by spectrophotometrical measurement of Evans Blue leakage. To examine the signaling pathway, B1 antagonist [des-Arg10]-HOE140 (0.1-1.0 microM) and B2 antagonist HOE140 (0.05-1.0 microM), calcitonin gene-related peptide (CGRP) antagonist CGRP8-37 (0.5-1.0 microM), prostaglandin E2 antagonist AH-6809 (0.1-1.0 microM), and histamine H1 antagonist mepyramine (0.1-1.0 microM) were used. Nociceptin (0.0001-1.0 microM) and antagonist J-113397 were tested for modulation of BK-induced PE. The analyses were compared side-by-side with 5-hydroxytryptamine-induced PE. RESULTS: BK perfusion dose-dependently induced PE, which was blocked by HOE140, CGRP8-37, AH-6809, and mepyramine. It was also inhibited by nociceptin, which could be reversed by antagonist J-113397. In contrast, 5-hydroxytryptamine-induced PE was biphasically regulated by nociceptin and was not antagonized by CGRP8-37. CONCLUSIONS: BK-induced PE is mediated by B2 receptors and may involve CGRP, prostaglandin, and histamine pathways. BK-induced PE is inhibited by nociceptin through the activation of ORL1 receptors. There are differences between BK- and 5-hydroxytryptamine-induced inflammation in signaling and modulation.

N-terminally truncated variant of the mouse GAIP/RGS19 lacks selectivity of full-length GAIP/RGS19 protein in regulating ORL1 receptor signaling.

The regulators of G protein signaling (RGS) are a family of proteins with conserved RGS domains and play essential roles in regulating G protein-mediated signal transduction and physiological events. GAIP/RGS19 (G alpha interacting protein, also classified as RGS19), a member of the RGS family, has been shown to negatively regulate the signaling of many G protein-coupled receptors, including the opioid receptors. Two GAIP/RGS19 mRNA variants, resulted from an alternative splicing of exon 2 of the GAIP/RGS19 gene, were identified in multiple mouse tissues. One of the transcripts consists of a complete set of exons and encodes a full-length GAIP/RGS19 protein, and the other does not have exon 2 and therefore encodes an N-terminal 22 residue truncated short GAIP/RGS19 protein. When co-expressed with either the opioid-receptor-like (ORL1) receptor or one of the mu, delta, and kappa opioid receptors, by transfecting dual-expression plasmids into COS-7 cells, the full-length GAIP/RGS19 was more effective than the N-terminally truncated variant and was more selective in regulating the ORL1 receptor signaling than in regulating the mu, delta, and kappa opioid receptors, as measured by the effectiveness to increase the agonist-stimulated GTPase activity and to reverse the agonist-induced inhibition of cyclic AMP accumulation. In the same assays, the N-terminally truncated GAIP/RGS19 did not distinguish ORL1 from the mu, delta, and kappa opioid receptors. In contrast, co-expression of RGS4 with either ORL1 or opioid receptors showed the selectivity of RGS4 for regulating opioid receptors was mu > kappa > delta > ORL1, an order completely different from that of GAIP/RGS19. The results suggest that GAIP/RGS19 prefers regulating ORL1 receptor signaling over other opioid receptors, and that the N-terminal domain of GAIP/RGS19 plays a crucial role in its receptor preference.

Differential expression of the regulator of G protein signaling RGS9 protein in nociceptive pathways of different age rats.

Regulators of G protein signaling (RGS) proteins are GTPase-activating proteins which act as modulators of G-protein-coupled receptors. RGS9 has two alternative splicing variants. RGS9-1 is expressed in the retina. RGS9-2 is expressed in the brain, especially abundant in the striatum. It is believed to be an essential regulatory component of dopamine and opioid signaling. In this study, we compared the expression of RGS9 proteins in the nervous system of different age groups of rats employing immunocytochemistry. In both 3-week- and 1-year-old rats, RGS9 is expressed abundantly in caudate-putamen, nucleus accumbens, and olfactory tubercle. It is also expressed abundantly in the ventral horn of the spinal cord and the dorsal root ganglion (DRG) cells. Quantitative analysis showed that the intensities of RGS9 expression in 1-year-old rats are higher than those in the 3-week-old rats in caudate-putamen, nucleus accumbens, olfactory tubercle, periaqueductal gray, and gray matter of the spinal cord. In contrast, in thalamic nuclei and locus coeruleus, the intensities of RGS9 immunostaining in 3-week-old rats are higher than in 1-year-old rats. In DRG cells, there is no significant difference between the two age groups. These data suggest that RGS9 is differentially expressed with age. Such differential expression may play an important role in neuronal differentiation and development as well as in neuronal function, such as dopamine and opioid signaling.

Gene structure, dual-promoters and mRNA alternative splicing of the human and mouse regulator of G protein signaling GAIP/RGS19.

Here we report the gene structure and transcription regulation of the human and mouse G protein-signaling regulator GAIP/RGS19. The GAIP/RGS19 gene is adjacent to and in an opposite orientation to the opioid-receptor-like receptor 1 (ORL1) gene. In both human and mouse, the GAIP/RGS19 gene is composed of seven exons. The first two exons are under the control of two different promoters and are alternatively employed to start the transcription of two 5' distinctive mRNAs. The two promoters appear to compete with and inhibit each other. We have also identified in mice an alternatively spliced short GAIP/RGS19 mRNA that lacks the exon 2 region and utilizes an ATG in exon 3 as its translation initiation codon. As a result, the short GAIP/RGS19 protein does not have the N-terminal 22 amino acid residues of a full-length isoform. GAIP/RGS19 alternative splicing patterns are differentially expressed in various tissues. The mRNA alternative splicing to produce multiple isoforms may play a significant role in regulating the function and selectivity of GAIP/RGS19.