Tujuan penelitian ini adalah untuk mendapatkan bukti empiris tentang pengaruh kecepatan reaksi tangan, terhadap kemampuan forehand topspin.. Penelitian ini dilakukan pada atlet tenis meja Unsika ...Karawang. Keseluruhan populasi berjumlah 56 orang, sampel dipilih dengan menggunakan teknik pertimbangan/ purposive sampling, dan sampel dalam penelitian ini berjumlah 30 atlet tenis meja. Hasil tes kecepatan reaksi tangan berpengaruh langsung terhadap kemampuan forehand tospin sebesar 0,0957. Penelitian ini menggunakan pendekatan kuantitatif asosiatif dengan teknik analyisis jalur. Hasil mengungkapkan bahwa; terdapat pengaruh positif secara langsung kecepatan reaksi tangan terhadap kemampuan forehand topspin. Kata kunci; Kecepatan Reaksi Tangan, Forehand Topspin
This study aims to determine the results and analyze table tennis service skills in students who take table tennis extracurricular at SMP Negeri 19 Palembang. This research is a quantitative ...descriptive research. The research sample was 15 students who took part in table tennis extracurricular activities. The results of this study are the forehand service skills of students with good classification as many as (3) people (20%), moderate classification (9) people (60%), poor classification as many as (3) people (20%). While the backhand service skills are very good classification students as many as (1) people (7%), good classification as many as (4) people (27%), moderate classification (8) people (53%), poor classification as many as (2) people ( 13%). Thus, it can be concluded that the results of the forehand and backhand service level of table tennis students who participate in table tennis extracurricular activities at SMP Negeri 19 Palembang can be categorized as moderate with an average forehand service of 5.5, while the average result of backhand serving is 4, 8.
The results of this study aim to see the role of multiball how much it increases backhand stroke skills in table tennis and how the role of multiball exercises is to improve backhand stroke skills in ...table tennis games. The research was conducted by random sampling to a population of all Sparta athletes, totaling 45 people. Data collection using the method of test and measurement techniques. The test instrument used is multiball to determine the effect of multiball training. The variables in this study include Multiball as the independent variable, as well as improving backhand skills as the dependent variable. The data analysis technique uses descriptive analysis techniques and inferential analysis through the SPSS.22 program with a significance level of 95% (α = 0.05)The results of the research analysis show that: (1) multiball training is proven to increase backhand shots with a contribution of 64.5%;(2) The multiball training group has a greater effect on increasing backhand strokes than the control with an increase in out shuffle-plyo push ups of 12.85% of the average pretest carried out before treatment with an average posttest, while for the control it is only 3.9 % of the average pretest and posttest scores.
Naturally synthesized secondary metabolites in plants are considered an important source of drugs, food additives, etc. Among them, research on natural plant medicinal components and their synthesis ...mechanisms has always been of high concern. We identified a novel medicinal floral crop, Plumbago auriculata L., that can be treated with methyl jasmonate (MeJA) for the rapid or sustainable production of natural bioactives from hairy roots. In the study, we globally analyzed the changes in the accumulation of plumbagin and others in the hairy roots of Plumbago auriculata L. hairy roots (PAHR) 15834 in P. auriculata L. based on 100 μmol/L of MeJA treatment by RNA-seq profiling, and we found that there was a significant increase in the accumulation of plumbagin and saponin before 24 h. To explain the principle of co-accumulation, it showed that MeJA induced JA signaling and the shikimic acid pathway, and the methylvaleric acid (MVA) pathway was activated downstream subsequently by the Mfuzz and weighted gene co-expression analysis. Under the shared metabolic pathway, the high expression of PAL3 and HMGR promoted the activity of the “gateway enzymes” phenylalanine ammonia lyase (PAL) and 3-hydroxy-3-methylglutaryl CoA reductase (HMGR), which respectively induced the high expression of key reaction enzyme genes, including chalcone synthase (CHS), isopentenyl diphosphate (IPP), and farnesyl pyrophosphate synthase (FPS), that led to the synthesis of plumbagin and saponin. We speculated that large amounts of ketones and/or aldehydes were formed under the action of these characteristic enzymes, ultimately achieving their co-accumulation through polyketone and high-level sugar and amino acid metabolism. The study results provided a theoretical basis for carrying out the factory refinement and biosynthesis of plumbagin and saponins and also provided new ideas for fully exploiting multifunctional agricultural crops and plants and developing new agricultural by-products.
Artemisia argyi , a perennial herb of the genus Artemisia in the family Asteraceae, holds significant importance in Chinese traditional medicine, referred to as “Aicao”. Here, we report a ...high-quality reference genome of Artemisia argyi L. cv. beiai, with a genome size up to 4.15 Gb and a contig N50 of 508.96 Kb, produced with third-generation Nanopore sequencing technology. We predicted 147,248 protein-coding genes, with approximately 68.86% of the assembled sequences comprising repetitive elements, primarily long terminal repeat retrotransposons(LTRs). Comparative genomics analysis shows that A. argyi has the highest number of specific gene families with 5121, and much more families with four or more members than the other 6 plant species, which is consistent with its more expanded gene families and fewer contracted gene families. Furthermore, through transcriptome sequencing of A. argyi in response to exogenous MeJA treatment, we have elucidated acquired regulatory insights into MeJA’s impact on the phenylpropanoid, flavonoid, and terpenoid biosynthesis pathways of A. argyi . The whole-genome information obtained in this study serves as a valuable resource for delving deeper into the cultivation and molecular breeding of A. argyi . Moreover, it holds promise for enhancing genome assemblies across other members of the Asteraceae family. The identification of key genes establishes a solid groundwork for developing new varieties of Artemisia with elevated concentrations of active compounds.
SmJAZ8 regulates the biosynthesis of salvianolic acids and tanshinones simultaneously by repressing the transcription factors and biosynthetic pathway genes in Salvia miltiorrhiza hairy roots.
...Abstract
Jasmonates (JAs) are important plant hormones that regulate a variety of plant development and defense processes, including biosynthesis of secondary metabolites. The JASMONATE ZIM DOMAIN (JAZ) proteins act as negative regulators in the JA signaling pathways of plants. We first verified that methyl jasmonate (MeJA) enhanced the accumulation of both salvianolic acids and tanshinones in Salvia miltiorrhiza (Danshen) hairy roots by inducing the expression of their biosynthetic pathway genes. Nine JAZ genes were cloned from Danshen and their expression levels in hairy roots were all increased by treatment with MeJA. When analyzed in detail, however, SmJAZ8 showed the strongest expression in the induced hairy roots. Overexpression or RNAi of SmJAZ8 deregulated or up-regulated the yields of salvianolic acids and tanshinones in the MeJA-induced transgenic hairy roots, respectively, and transcription factors and biosynthetic pathway genes showed an expression pattern that mirrored the production of the compounds. Genetic transformation of SmJAZ8 altered the expression of other SmJAZ genes, suggesting evidence of crosstalk occurring in JAZ-regulated secondary metabolism. Furthermore, the transcriptome analysis revealed a primary-secondary metabolism balance regulated by SmJAZ8. Altogether, we propose a novel role for SmJAZ8 as a negative feedback loop controller in the JA-induced biosynthesis of salvianolic acids and tanshinones.
•MeJA treatment improved the cold resistance of green bell pepper.•MeJA treatment changed the membrane lipid component of green bell pepper.•MeJA treatment reduced CI of green bell pepper by ...regulating membrane lipid metabolism.
The effects of methyl jasmonate (MeJA) treatment on membrane lipid metabolism of green bell pepper during cold storage was studied. The results showed that the chilling injury (CI) index, electrolyte leakage, malondialdehyde (MDA) content, phospholipase D (PLD) activity and gene expression of green bell pepper treated with MeJA were lower than those of the control fruit. MeJA treatment was able to maintain a higher level of ascorbic acid (VC) content, higher levels of phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylserine (PS) and lower levels of digalactosyldiacylglycerol (DGDG), phosphatidic acid (PA), digalactosyldiacylglycerol/monogalactosyldiacylglycerol (DGDG/MGDG) and PC/PE compared to control fruit. In addition, MeJA treatment can also increase the proline content of green bell pepper fruit. Therefore, the reason that MeJA can improve the cold resistance of green bell pepper fruit may be attributed by the decreased expression and activity of PLD gene. The degradation of membrane lipid was delayed, and the content of proline increased, thereby maintaining cell membrane stability.
Chilling injury (CI) is a physiological disorder induced by cold, which heavily limit crop production and postharvest preservation worldwide. Methyl jasmonate (MeJA) can alleviate CI in various fruit ...species, including peach; however, the underlying molecular mechanism is poorly understood. Here, changes in contents of phenolics, lipids, and jasmonic acid (JA) and gene expressions are compared between MeJA and control fruit. Exogenous MeJA inhibited expressions of PpPAL1, PpPPO1, and PpPOD1/2 but did not affect the phenolic content. Furthermore, MeJA fruit showed lower relative electrolyte leakage, indicating less membrane damage. Meanwhile, the enrichment of linoleic acid in the potential lipid biomarkers, especially phosphatidylcholine, phosphatidylethanolamine, and phosphatidylglycerol, coincided with lower expressions of PpFAD8.1 but higher PpLOX3.1 and JA content. In the JA signaling pathway, MeJA significantly upregulated expressions of PpMYC2.2 and PpCBF3 but downregulated PpMYC2.1. In conclusion, adjustments of fatty acids in phospholipids contribute to MeJA-induced alleviation of CI in peach fruit via induction of the JA-mediated C-repeat-binding factor pathway.
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