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Frontiers in Plant Science 2019Shoot branching is regulated by phytohormones, including cytokinin (CK), strigolactone (SL), and auxin in axillary buds. The correlative importance of these...
Shoot branching is regulated by phytohormones, including cytokinin (CK), strigolactone (SL), and auxin in axillary buds. The correlative importance of these phytohormones in the outgrowth of apple axillary buds remains unclear. In this study, the outgrowth dynamics of axillary buds of a more-branching mutant (MB) and its wild-type (WT) of were assessed using exogenous chemical treatments, transcriptome analysis, paraffin section, and reverse transcription-quantitative PCR analysis (RT-qPCR). High contents of CK and abscisic acid coincided in MB axillary buds. Exogenous CK promoted axillary bud outgrowth in the WT but not in MB, whereas exogenous gibberellic had no significant effect on bud outgrowth in the WT. Functional analysis of transcriptome data and RT-qPCR analysis of gene transcripts revealed that MB branching were associated with CK signaling, auxin transport, and SL signaling. Transcription of the SL-related genes , and in the axillary buds of MB was generally upregulated during bud outgrowth, whereas / were generally downregulated both in WT and MB. Exogenous SL inhibited outgrowth of axillary buds in the WT and the apple varieties T337, M26, and Nagafu 2, whereas axillary buds of the MB were insensitive to SL treatment. Treatment with -1-naphthylphalamic acid (NPA; an auxin transport inhibitor) inhibited bud outgrowth in plants of the WT and MB. The transcript abundance of was generally decreased in response to NPA and SL treatments, and increased in CK and decapitation treatments, whereas no consistent pattern was observed for and . Collectively, the present results suggest that in apple auxin transport from the axillary bud to the stem may be essential for the outgrowth of axillary buds, and at least, is involved in the process of bud outgrowth.
PubMed: 31156679
DOI: 10.3389/fpls.2019.00616 -
Animals : An Open Access Journal From... Oct 2023Refinement of experimental procedures in animal research has the objective of preventing and minimizing pain/distress in animals, including the euthanasia period. This...
Refinement of experimental procedures in animal research has the objective of preventing and minimizing pain/distress in animals, including the euthanasia period. This study aimed to evaluate pain associated with six methods of euthanasia in Wistar rats (injectable, inhalational, and physical), by applying the Rat Grimace Scale (RGS), comparing the scores, and determining the method with the highest score that might indicate pain for laboratory rodents. Sixty adult male and female Wistar rats were used and assigned to six treatments: pentobarbital, CO, decapitation, isoflurane, ketamine + xylazine, and ketamine + CO. Video recording to assess the RGS scores was performed in four events: basal: 24 h before the procedure; Ti: three minutes before the procedure; Ti: during the application of the euthanasia method; and Ti: immediately after the application until LORR. The main findings of this study showed that, during Ti, decapitation and ketamine + xylazine had the highest scores (0.6 ± 0.26 and 0.6 ± 0.16, respectively) ( < 0.0001), while at Ti, CO (0.9 ± 0.18) and isoflurane (1.2 ± 0.20) recorded the highest scores ( < 0.0001). According to the present results, decapitation and ketamine + xylazine elicited short-term acute pain, possibly due to tissue damage caused by both methods (injection and guillotine). In contrast, isoflurane's RGS scores recorded during Ti might be associated with nociception/pain due to the pungency of the drug or to the pharmacological muscle relaxant effect of isoflurane. Further research is needed to establish a comprehensive study of pain during euthanasia, where RGS could be used minding the limitations that anesthetics might have on facial expression.
PubMed: 37893885
DOI: 10.3390/ani13203161 -
Current Biology : CB Sep 2022A key aim in biology is to identify which genetic changes contributed to the evolution of form through time. Apical dominance, the inhibitory effect exerted by shoot...
A key aim in biology is to identify which genetic changes contributed to the evolution of form through time. Apical dominance, the inhibitory effect exerted by shoot apices on the initiation or outgrowth of distant lateral buds, is a major regulatory mechanism of plant form. Nearly a century of studies in the sporophyte of flowering plants have established the phytohormone auxin as a front-runner in the search for key factors controlling apical dominance, identifying critical roles for long-range polar auxin transport and local auxin biosynthesis in modulating shoot branching. A capacity for lateral branching evolved by convergence in the gametophytic shoot of mosses and primed its diversification; however, polar auxin transport is relatively unimportant in this developmental process, the contribution of auxin biosynthesis genes has not been assessed, and more generally, the extent of conservation in apical dominance regulation within the land plants remains largely unknown. To fill this knowledge gap, we sought to identify genetic determinants of apical dominance in the moss Physcomitrium patens. Here, we show that leafy shoot apex decapitation releases apical dominance through massive and rapid transcriptional reprogramming of auxin-responsive genes and altering auxin biosynthesis gene activity. We pinpoint a subset of P. patens TRYPTOPHAN AMINO-TRANSFERASE (TAR) and YUCCA FLAVIN MONOOXYGENASE-LIKE (YUC) auxin biosynthesis genes expressed in the main and lateral shoot apices and show that they are essential for coordinating branch initiation and outgrowth. Our results demonstrate that local auxin biosynthesis acts as a pivotal regulator of apical dominance in moss and constitutes a shared mechanism underpinning shoot architecture control in land plants.
Topics: Bryophyta; Bryopsida; Gene Expression Regulation, Plant; Germ Cells, Plant; Indoleacetic Acids; Plant Growth Regulators; Plant Shoots
PubMed: 35841890
DOI: 10.1016/j.cub.2022.06.064 -
International Journal of Molecular... Sep 2022The cytokinin (CK) response regulator (RR) gene family plays a pivotal role in regulating the developmental and environmental responses of plants. Axillary bud outgrowth...
The cytokinin (CK) response regulator (RR) gene family plays a pivotal role in regulating the developmental and environmental responses of plants. Axillary bud outgrowth in the perennial woody plant is regulated by the crosstalk between CK and gibberellins (GA). In this study, we first analyzed the effects of gibberellin A3 (GA), lovastatin (a CK synthesis inhibitor), decapitation, and their interaction, on the outgrowth of axillary buds. The results indicate that lovastatin completely inhibited GA-promoted axillary bud outgrowth and partially weakened the decapitation-promoted axillary bud outgrowth. To further characterize and understand the role of CK signaling in promoting the development of female flowers and branches, we performed bioinformatics and expression analyses to characterize the CK RR gene () family in . A total of 14 members of the JcRR family were identified; these genes were distributed on 10 chromosomes. Phylogenetic analysis indicated that the corresponding RR proteins are evolutionarily conserved across different plant species, and the Myb-like DNA-binding domain divides the 14 members of the JcRR family into type-A and type-B proteins. Further analysis of -acting elements in the promoter regions of suggests that are expressed in response to phytohormones, light, and abiotic stress factors; thus, may be involved in some plant development processes. Genomic sequence comparison revealed that segmental duplication may have played crucial roles in the expansion of the JcRR gene family, and five pairs of duplicated genes were all subjected to purifying selection. By analyzing RNA sequencing (RNA-seq) and quantitative reverse transcription-polymerase chain reaction (qRT-PCR) data, we characterized that the temporospatial expression patterns of during the development of various tissues and the response of these genes to phytohormones and abiotic stress. The were mainly expressed in the roots, while they also exhibited differential expression patterns in other tissues. The expression levels of all six type-A and one type-B increased in response to 6-benzylaminopurine (6-BA), while the four type-B levels decreased. The expression levels of two type-B increased in response to exogenous GA treatment, while those of three type-A and three type-B decreased. We found that type-A may play a positive role in the continuous growth of axillary buds, while the role of type-B might be the opposite. In response to abiotic stress, the expression levels of two type-A and three type-B strongly increased. The overexpression of in slightly increased the numbers of rosette branches after decapitation, but not under normal conditions. In conclusion, our results provide detailed knowledge of for further analysis of CK signaling and functions in .
Topics: Arabidopsis; Cytokinins; DNA; Decapitation; Gene Expression Regulation, Plant; Gibberellins; Jatropha; Lovastatin; Phylogeny; Plant Growth Regulators; Plant Proteins
PubMed: 36232689
DOI: 10.3390/ijms231911388 -
Plants (Basel, Switzerland) Jul 2023() is a crucial member of the (TCP) gene family and is well known for playing a central role in shoot branching by controlling buds' paradormancy. However, the...
() is a crucial member of the (TCP) gene family and is well known for playing a central role in shoot branching by controlling buds' paradormancy. However, the expression characteristics and molecular regulatory mechanism of during blueberry bud dormancy are unclear. To shed light on these topics, shoots of three blueberry cultivars with different chilling requirements (CRs) were decapitated in summer to induce paradormancy release and subjected to different levels of chilling in winter to induce endodormancy release. The results showed that the high-CR cultivar 'Chandler' had the strongest apical dominance among the three cultivars; additionally, the expression of , which is homologous to , was the highest under both the decapitation treatment and low-temperature treatment. The 'Emerald' cultivar, with a low CR, demonstrated the opposite trend. These findings suggest that plays a negative regulatory role in bud break and that there may be a correlation between the CR and tree shape. Through yeast 1-hybrid (Y1H) assays, we finally screened 21 upstream regulatory genes, including eight transcription factors: zinc-finger homeodomain protein 1/4/5/9, MYB4, AP2-like ethylene-responsive transcription factor AINTEGUMENTA (ANT), ASIL2-like, and bHLH035. It was found that these upstream regulatory genes positively or negatively regulated the expression of based on the transcriptome expression profile. In summary, this study enriched our understanding of the regulatory network of during bud dormancy and provided new insights into the function of .
PubMed: 37514210
DOI: 10.3390/plants12142595 -
BMC Genomics Jun 2023Branching is a plastic character that affects plant architecture and spatial structure. The trait is controlled by a variety of plant hormones through coordination with...
BACKGROUND
Branching is a plastic character that affects plant architecture and spatial structure. The trait is controlled by a variety of plant hormones through coordination with environmental signals. Plant AT-rich sequence and zinc-binding protein (PLATZ) is a transcription factor that plays an important role in plant growth and development. However, systematic research on the role of the PLATZ family in apple branching has not been conducted previously.
RESULTS
In this study, a total of 17 PLATZ genes were identified and characterized from the apple genome. The 83 PLATZ proteins from apple, tomato, Arabidopsis, rice, and maize were classified into three groups based on the topological structure of the phylogenetic tree. The phylogenetic relationships, conserved motifs, gene structure, regulatory cis-acting elements, and microRNAs of the MdPLATZ family members were predicted. Expression analysis revealed that MdPLATZ genes exhibited distinct expression patterns in different tissues. The expression patterns of the MdPLATZ genes were systematically investigated in response to treatments that impact apple branching [thidazuron (TDZ) and decapitation]. The expression of MdPLATZ1, 6, 7, 8, 9, 15, and 16 was regulated during axillary bud outgrowth based on RNA-sequencing data obtained from apple axillary buds treated by decapitation or exogenous TDZ application. Quantitative real-time PCR analysis showed that MdPLATZ6 was strongly downregulated in response to the TDZ and decapitation treatments, however, MdPLATZ15 was significantly upregulated in response to TDZ, but exhibited little response to decapitation. Furthermore, the co-expression network showed that PLATZ might be involved in shoot branching by regulating branching-related genes or mediating cytokinin or auxin pathway.
CONCLUSION
The results provide valuable information for further functional investigation of MdPLATZ genes in the control of axillary bud outgrowth in apple.
Topics: Malus; Phylogeny; Decapitation; Genes, Plant; Plant Shoots; Gene Expression Regulation, Plant; Plant Proteins
PubMed: 37322464
DOI: 10.1186/s12864-023-09399-x -
The Plant Journal : For Cell and... Dec 2020Two branching strategies are exhibited in crops: enhanced apical dominance, as in maize; or weak apical dominance, as in rice. However, the underlying mechanism of weak...
Two branching strategies are exhibited in crops: enhanced apical dominance, as in maize; or weak apical dominance, as in rice. However, the underlying mechanism of weak apical dominance remains elusive. OsWUS, an ortholog of Arabidopsis WUSCHEL (WUS) in rice, is required for tiller development. In this study, we identified and functionally characterized a low-tillering mutant decreased culm number 1 (dc1) that resulted from loss-of-function of OsWUS. The dc1 tiller buds are viable but repressed by the main culm apex, leading to stronger apical dominance than that of the wild-type (WT). Auxin response is enhanced in the dc1 mutant, and knocking out the auxin action-associated gene ABERRANT SPIKELET AND PANICLE 1 (ASP1) de-repressed growth of the tiller buds in the dc1 mutant, suggesting that OsWUS and ASP1 are both involved in outgrowth of the rice tiller bud. Decapitation triggers higher contents of cytokinins in the shoot base of the dc1 mutant compared with those in the WT, and exogenous application of cytokinin is not sufficient for sustained growth of the dc1 tiller bud. Transcriptome analysis indicated that expression levels of transcription factors putatively bound by ORYZA SATIVA HOMEOBOX 1 (OSH1) are changed in response to decapitation and display a greater fold change in the dc1 mutant than that in the WT. Collectively, these findings reveal an important role of OsWUS in tiller bud growth by influencing apical dominance, and provide the basis for an improved understanding of tiller bud development in rice.
Topics: Gene Knockdown Techniques; Oryza; Plant Proteins; Plant Stems
PubMed: 33064890
DOI: 10.1111/tpj.15026 -
Horticulture Research Sep 2023Jujube witches' broom (JWB) phytoplasmas parasitize the sieve tubes of diseased phloem and cause an excessive proliferation of axillary shoots from dormant lateral buds...
Jujube witches' broom (JWB) phytoplasmas parasitize the sieve tubes of diseased phloem and cause an excessive proliferation of axillary shoots from dormant lateral buds to favour their transmission. In previous research, two JWB effectors, SJP1 and SJP2, were identified to induce lateral bud outgrowth by disrupting ZjBRC1-mediated auxin flux. However, the pathogenesis of JWB disease remains largely unknown. Here, tissue-specific transcriptional reprogramming was examined to gain insight into the genetic mechanisms acting inside jujube lateral buds under JWB phytoplasma infection. JWB phytoplasmas modulated a series of plant signalling networks involved in lateral bud development and defence, including auxin, abscisic acid (ABA), ethylene, jasmonic acid, and salicylic acid. JWB-induced bud outgrowth was accompanied by downregulation of ABA synthesis within lateral buds. ABA application rescued the bushy appearances of transgenic overexpressing and in Col-0 and in the mutant. Furthermore, the expression of and ABA-related genes and was negatively correlated with lateral main bud outgrowth in decapitated healthy jujube. Molecular evidence showed that ZjBRC1 interacted with ZjBRC2 via its N-terminus to activate and expression and ABA accumulation in transgenic jujube calli. In addition, widely regulated differentially expressed genes related to ABA homeostasis and ABA signalling, especially by binding to and suppressing ABA receptors. Therefore, these results suggest that JWB phytoplasmas hijack the -mediated ABA pathways to stimulate lateral bud outgrowth and expansion, providing a strategy to engineer plants resistant to JWB phytoplasma disease and regulate woody plant architecture to promote crop yield and quality.
PubMed: 37691966
DOI: 10.1093/hr/uhad148 -
EXCLI Journal 2017This experimental study aimed to investigate the protective effect of a bioflavonoid, hesperidin (HP), on formaldehyde (FA)-related pathophysiological and behavioral...
This experimental study aimed to investigate the protective effect of a bioflavonoid, hesperidin (HP), on formaldehyde (FA)-related pathophysiological and behavioral outcomes in pregnant rats and developmental aspects in their offspring. Female Wistar rats were subjected to perigestational exposure to FA (2 mg/kg/day ) with a concomitant treatment with HP (50 mg/kg/day ). Pregnant rats were weighed throughout gestation and tested in two behavioral paradigms (elevated plus-maze and open field) at gestational days (GD) 1, 10 and 19 to evaluate the anxiety-like behavior and locomotive alterations. Another subset of rats was decapitated at GD19 to determine the hematological profile along with cortisol, 17β-estradiol, and progesterone plasma levels. Reproductive and fetal measures and observations were also performed to check for developmental deformities. Significant body weight loss, hemato-immune decline, hormonal changes, anxiety and lethargy signs, locomotor disabilities, reproductive failure and fetal weight decrease were observed in FA-exposed rats. Treatment with HP alleviated the reproductive and fetal weight defects. Its behavioral benefits were only seen at GD1 and 10. This flavanone ameliorated some hematological parameters, decreased cortisol levels and increased 17β-estradiol rates. A potential preventive impact of HP was found against FA toxicity in pregnant rats.
PubMed: 28507483
DOI: 10.17179/excli2017-142 -
The Journal of International Advanced... Aug 2019This study aimed to evaluate the effect of quercetin on cochlear function and morphology, and its possible protective effect against acute cisplatin-induced ototoxicity...
OBJECTIVES
This study aimed to evaluate the effect of quercetin on cochlear function and morphology, and its possible protective effect against acute cisplatin-induced ototoxicity in rats.
MATERIALS AND METHODS
This prospective and controlled animal study was conducted on Wistar albino rats divided into four groups. Otoacoustic emission measures were performed three days after the first infiltration in Group 1 (saline), 2 (cisplatin), and 3 (quercetin). This interval was five days for Group 4 (cisplatin+quercetin). At the end of the study, the rats were decapitated with deep anesthesia, and histological changes in the cochleas were observed by light microscopy.
RESULTS
Group 2 (cisplatin) revealed significant differences between the first and second measures in all frequencies. When compared to other group, the difference of the changes in Group 2 statistically significantly decreased, especially in higher frequencies. Morphologically, there were no acute changes in Group 1 and Group 3. Outer hair cell loss and the degeneration of stria vascularis and spiral ganglion were observed in both Groups 2 and 4; the damages in the latter were lesser.
CONCLUSION
Quercetin does not have negative effect on cochlea, and it has protective effect on cisplatin-induced ototoxicity.
Topics: Analysis of Variance; Animals; Antineoplastic Agents; Antioxidants; Cisplatin; Female; Organ of Corti; Ototoxicity; Quercetin; Rats, Wistar; Stria Vascularis
PubMed: 31287434
DOI: 10.5152/iao.2019.5902