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Stevioside is a non-caloric, natural, high-intensity sweetener. However, the bitter aftertaste of stevioside restricts its utilization for human consumption and limits its application in the food industry. In this study, a high efficiency enzymatic modification system was investigated to improve stevioside taste quality. A cyclodextrin glucanotransferase (CGTase) producing strain Paenibacillus sp. CGMCC 5316 was isolated from Stevia planting soil. With starch as glycosyl donor, this CGTase can transform stevioside into a single specific product which is an isomer of rebaudioside A and identified as mono-glycosylated stevioside . The taste of stevioside is improved noticeably by generating mono-glycosylated stevioside, which possesses a sucrose-like taste and has sweetness increased significantly by 35.4 %. Next, the parameters influencing CGTase production were optimized. Compared to initial conditions, CGTase activity increased by 214.7 % under optimum conditions of 3.9 g/L starch, 17.9 g/L tryptone, and 67.6 h of culture time, and the transglycosylation rate of stevioside was remarkably increased by 284.8 %, reaching 85.6 %. This CGTase modification system provides a promising solution for improving the sweetness and taste quality of stevioside. The efficiency of CGTase transformation can be greatly increased by optimizing the culture conditions of Paenibacillus sp. CGMCC 5316. [ABSTRACT FROM AUTHOR]

Background: Yield and quality are the two most important traits in crop breeding. Exploring the regulatory mechanisms that affect both yield and quality traits is of great significance for understanding the molecular genetic networks controlling these key crop attributes. Expansins are cell wall loosening proteins that play important roles in regulating rice grain size. Results: We investigated the effect of OsEXPA7, encoding an expansin, on rice grain size and quality. OsEXPA7 overexpression resulted in increased plant height, panicle length, grain length, and thousand-grain weight in rice. OsEXPA7 overexpression also affected gel consistency and amylose content in rice grains, thus affecting rice quality. Subcellular localization and tissue expression analyses showed that OsEXPA7 is localized on the cell wall and is highly expressed in the panicle. Hormone treatment experiments revealed that OsEXPA7 expression mainly responds to methyl jasmonate, brassinolide, and gibberellin. Transcriptome analysis and RT-qPCR experiments showed that overexpression of OsEXPA7 affects the expression of OsJAZs in the jasmonic acid pathway and BZR1 and GE in the brassinosteroid pathway. In addition, OsEXPA7 regulates the expression of key quantitative trait loci related to yield traits, as well as regulates the expression levels of BIP1 and bZIP50 involved in the seed storage protein biosynthesis pathway. Conclusions: These results reveal that OsEXPA7 positively regulates rice yield traits and negatively regulates grain quality traits by involving plant hormone pathways and other trait-related pathway genes. These findings increase our understanding of the potential mechanism of expansins in regulating rice yield and quality traits and will be useful for breeding high-yielding and high-quality rice cultivars. [ABSTRACT FROM AUTHOR]

In recent years, MRI has been regarded as a major diagnostic tool for spondyloarthritis (SpA), and anti-TNF therapy has been widely confirmed as an effective treatment strategy. This study was designed to investigate the correlation between the secreted protein dickkopf-1 (Dkk-1) and abnormal findings on magnetic resonance imaging (MRI) through a prospective study of 30 cases of SpA. Thirty patients with active SpA were included, all treated with recombinant human tumor necrosis factor (TNF) receptor-antibody fusion protein (YiSaiPu) injection at 50 mg/week for 6 months. All patients were also examined for their clinical, serological, and imaging manifestations of the condition before and after treatment. In patients receiving TNF inhibitor treatment, the erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and clinical activity indices BASDAI, BASFI, BASMI, ASDAS-CRP were significantly decreased (p < 0.01). Serum Dkk-1 concentration was also significantly decreased (p < 0.05), as were the scores of bone marrow edema of the sacroiliac joints and the spine (p < 0.05). The score of sacroiliac joint backfill was significantly increased (p < 0.05), and the baseline and changes in the serum Dkk-1 concentration were significantly correlated with the baseline and changes in spinal bone marrow edema levels. Inhibition of the level of serum Dkk-1 by TNF inhibitors may be the molecular basis for inhibiting the formation of new bone in SpA patients. In addition, spinal marrow edema may have significance for predicting new bone formation. [ABSTRACT FROM AUTHOR]

Environmental stresses influence the growth of plants and the productivity of crops. Salinity is one of the most important abiotic stresses for agricultural crops. Programmed cell death (PCD) is induced by a variety of biotic and abiotic stresses in plants, including high salinity treatment. OsPDCD5, an ortholog of the mammalian-programmed cell death 5 gene, is up-regulated under low temperature and salt treatments in rice ( Oryza sativa). In this study, transgenic rice that constitutively expressed antisense- OsPDCD5 increased salt stress tolerance in unique ways by inhibiting PCD pathways and regulating specific groups of stress-related genes. Real-time quantitative PCR analysis showed that PCD pathways were inhibited under both normal conditions and salt stress in transgenic rice. Using transcript microarray analysis, 38 stress-related genes regulated in transgenic rice were identified, which appeared to render the transgenic rice adapted for salt stress conditions. Our results suggested that PCD pathways were inhibited and salt stress signaling pathways were regulated in transgenic rice even under normal growth conditions without stress. PCD was further inhibited and these stress-related genes were further regulated to increase tolerance to high salinity under salt stress conditions, thereby leading to build-up of stress protection mechanisms in transgenic rice. [ABSTRACT FROM AUTHOR]

Cotton ( Gossypium hirsutum L.) is an important crop that is used to produce both natural textile fiber and cottonseed oil. Cotton fiber is a unicellular trichome, whose length is critical to fiber quality and yield but difficult to modify. FCA was originally identified based on flowering time control in Arabidopsis. The function of the second RNA recognition motif (RRM) domain of Oryza sativa FCA in rice cell-size regulation has been previously reported, showing it to be highly conserved across dicotyledonous and monocotyledonous plants. The present study showed that the second RRM domain of Brassica napus FCA functioned in Gossypium hirsutum, leading to enlargement of multiple cell types, such as pollen, cotyledon petiole, and cotton fiber. In the resulting transgenic cotton, fiber length increased by ~10% and fiber yield per plant showed a dramatic increase, ranging from 35 to 66% greater than controls. Thus, this RRM domain may be a cell-size regulator and have great economic value in the cotton industry. [ABSTRACT FROM AUTHOR]

OsPDCD5 is the rice ( Oryza sativa L.) homolog of PDCD5, a gene involved in programmed cell death (PCD) regulation and highly conserved over time. PDCD5 overexpression in tumor cells enhances apoptosis triggered by growth factor or serum deprivation. In our previous research, constitutive OsPDCD5 overexpression induces early death in transgenic plants. In this study, an inducible OsPDCD5 expression strategy was employed to systematically study the role of OsPDCD5 in rice. With this system, OsPDCD5 was found to be capable of independently inducing cell death in three-leaf stage and older seedlings. These altered plants exhibited lesion mimic phenotype, abnormal leaf morphology, DNA fragmentation, hydrogen peroxide production, and mitochondrial distortion. In nature, RNA hybridization in situ has shown that OsPDCD5 expression was predominantly localized to the tapetal layer where PCD occurred. Transcript microarray analyses here revealed that many PCD-related genes were involved. These data, taken together, indicated that OsPDCD5-induced cell death is a kind of PCD. Nevertheless, OsPDCD5 failed to induce any visible morphological phenotypes in two-leaf stage and younger seedlings. Transcript microarray analyses and quantitative real-time polymerase chain reaction showed that the Bax inhibitor-1 (BI-1) mRNA concentration and the activity of an ubiquitin gene were specifically changed. Endogenous OsPDCD5 upregulation, induced by ectopic OsPDCD5 expression in three-leaf stage seedlings, was also absent in two-leaf stage seedlings, suggesting strongly that young seedlings could inhibit PCD at some level. [ABSTRACT FROM AUTHOR]

Reports the result of identifying genes differentially expressed in rice inflorescence meristem with the suppression subtractive hybridization technique. Meristem at different development stages; Northern blot analysis of cloned complementary DNA (cDNA); Summary of cDNA clones.

Determines that parental gene expression of maize in hybrid genetic background is different from that in the inbred lines. Reamplification of the cDNA to screen a corresponding cDNA library; Initiation factor gene.