scholarly journals A PRELIMINARY STUDY OF IN VIVO INJECTION OF AUXIN AND CYTOKININ INTO Rafflesia patma Blume FLOWER BUDS

2021 ◽  
Vol 24 (2) ◽  
Author(s):  
Sofi Mursidawati ◽  
Adhityo Wicaksono

The controlling mechanisms for the growth and differentiation of Rafflesia from a flower bud into the anthesis stage is currently unknown, particularly if any plant growth regulator (PGR) physiological pathways play some type of roles. In the wild, the number of flower buds available to study are extremely limited. In this study, we grouped six flower buds of Rafflesia patma Blume into three different treatments: two buds injected with auxin (indoleacetic acid, IAA), two buds injected with cytokinin (kinetin), and two buds injected with sterile distilled water as a control. Buds enlarged with both IAA and kinetin treatments compared to the control, but only buds injected with IAA showed a transition stage with the bract revealed (cupule-bract stage from previously cupule stage) within two weeks of five weeks of observation. These results raise further questions whether Rafflesia development is more likely due to auxin exposure when in flower bud as compared to cytokinin. Future studies should include increased sample size for treatments, enhanced PGR administration to allow exposure to the tissue and less tissue damage, injection of other PGRs such as gibberellin (GA) and jasmonic acid (JA), and histological tissue analysis to investigate PGR effects in depth.

Author(s):  
Devanesan Arul Ananth ◽  
Vijayaraghavan Mahalakshmi ◽  
Thilagar Sivasudha ◽  
Liron Klipcan ◽  
Zipora Tietel

Abstract Cassia auriculata is an Ayurvedic medicinal herb, traditionally indicated for diabetes and hyperlipidemia. Several works have demonstrated its antioxidant, antidiabetic and anti-hyperlipidemic activity in vivo and in vitro. Nevertheless, only a few works have investigated its phytochemical composition, and specifically, the polyphenolic composition of the various plant parts that are traditionally used. In this work, the polyphenolic composition of C. auriculata leaves, flowers and flower buds were evaluated using UPLC-QqQ-MS/MS. Our results demonstrated the polyphenolic profile of C. auriculata plant parts. A total of five benzoic acids, four hydroxycinnamic acids, three flavonoids and two other phenolic compounds were identified and quantified. Our results show that in C. auriculata leaves, flavonoids were most abundant (4204 µg/g DW), while in flowers benzoic acids were the most prominent (3924 µg/g DW). Total benzoic acid contents ranged from 1580 to 3924 µg/g DW in leaf and flower, respectively. Hydroxycinnamic acids ranged from 404 µg/g DW in flower buds to 2623 µg/g DW in leaves. Flavonoids showed the highest contents in leaves, while the lowest levels were observed in flowers (2626 µg/g DW). The meaning of the results is discussed in light of the bioactivities of phenolic compounds, concomitant with C. auriculata reported medicinal bioactivities. To our knowledge, this is the first work to identify and quantify polyphenolic compounds in flower and bud of C. auriculata.


2014 ◽  
Vol 65 (1-2) ◽  
pp. 73-82 ◽  
Author(s):  
Christophe Clement ◽  
Daniel Al-Awad ◽  
Jean C. Audran

The purpose of this study was to develop a protocol for <em>in vitro</em> conform pollen maturation, as a model to study the involvement of carbohydrates on pollen maturation in <em>Lilium</em>. <em>In vivo</em> and <em>in vitro</em> pollen maturations were followed and compared by transmission electron microscopy, and several <em>in vitro</em> parameters were tested in terms of carbohydrate physiology. <em>In vivo</em>, pollen maturation was initiated at the vacuolated microspore stage, and consisted of two successive phases. The first phase was characterized by reactivation of microspore organelles, followed by microspore mitosis, starch synthesis and vacuole breakdown. During the second phase, starch was progressively degraded whereas lipid and phytine reserves accumulated. <em>In vivo</em>, pollen maturation occured within 14 days and pollen germination rate was 73.6 ± 2.2%. We then attempted to realise <em>in vitro</em> pollen maturation starting from the vacuolated microspore stage. The best results were obtained with flower buds cultivated at 26<sup>o</sup>C, in 100 µmol/m<sup>2</sup>/s light, with a 16h/8h photoperiod on a modified Heller's medium supplemented with NAA (10<sup>-2</sup> mg/l) and sucrose (M/6). In these conditions, pollen maturation occured within 7 days only. <em>In vitro</em> matured pollen is cytologically comparable to <em>in vivo</em> developed pollen grains and the germination rate was 72.4 ± 3.7%. When flower buds were cultivated in the dark, the germination rate decreased, but this could be compensated by providing high sucrose concentrations (1M) in the medium. Further, photosynthesis inhibitors had the same effect on pollen maturation than the darkness, strongly suggesting that photosynthesis occurs in the flower bud and is important for pollen maturation in <em>Lilium</em>.


HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 447d-447
Author(s):  
Meriam Karlsson ◽  
Jeffrey Werner

Nine-week-old plants of Cyclamen persicum `Miracle Salmon' were transplanted into 10-cm pots and placed in growth chambers at 8, 12, 16, 20, or 24 °C. The irradiance was 10 mol/day per m2 during a 16-h day length. After 8 weeks, the temperature was changed to 16 °C for all plants. Expanded leaves (1 cm or larger) were counted at weekly intervals for each plant. The rate of leaf unfolding increased with temperature to 20 °C. The fastest rate at 20 °C was 0.34 ± 0.05 leaf/day. Flower buds were visible 55 ± 7 days from start of temperature treatments (118 days from seeding) for the plants grown at 12, 16, or 20 °C. Flower buds appeared 60 ± 6.9 days from initiation of treatments for plants grown at 24 °C and 93 ± 8.9 days for cyclamens grown at 8 °C. Although there was no significant difference in rate of flower bud appearance for cyclamens grown at 12, 16, or 20 °C, the number of leaves, flowers, and flower buds varied significantly among all temperature treatments. Leaf number at flowering increased from 38 ± 4.7 for plants at 12 °C to 77 ± 8.3 at 24 °C. Flowers and flower buds increased from 18 ± 2.9 to 52 ± 11.0 as temperature increased from 12 to 24 °C. Plants grown at 8 °C had on average 6 ± 2 visible flower buds, but no open flowers at termination of the study (128 days from start of treatments).


Biomolecules ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 866
Author(s):  
Luong Huu Dang ◽  
Yuan Tseng ◽  
How Tseng ◽  
Shih-Han Hung

In this study, we developed a new procedure for the rapid partial decellularization of the harvested trachea. Partial decellularization was performed using a combination of detergent and sonication to completely remove the epithelial layers outside of the cartilage ring. The post-decellularized tracheal segments were assessed with vital staining, which showed that the core cartilage cells remarkably remained intact while the cells outside of the cartilage were no longer viable. The ability of the decellularized tracheal segments to evade immune rejection was evaluated through heterotopic implantation of the segments into the chest muscle of rabbits without any immunosuppressive therapy, which demonstrated no evidence of severe rejection or tissue necrosis under H&E staining, as well as the mechanical stability under stress-pressure testing. Finally, orthotopic transplantation of partially decellularized trachea with no immunosuppression treatment resulted in 2 months of survival in two rabbits and one long-term survival (2 years) in one rabbit. Through evaluations of posttransplantation histology and endoscopy, we confirmed that our partial decellularization method could be a potential method of producing low-immunogenic cartilage scaffolds with viable, functional core cartilage cells that can achieve long-term survival after in vivo transplantation.


2021 ◽  
Vol 22 (8) ◽  
pp. 3932
Author(s):  
Jing Cao ◽  
Qijiang Jin ◽  
Jiaying Kuang ◽  
Yanjie Wang ◽  
Yingchun Xu

The lotus produces flower buds at each node, yet most of them are aborted because of unfavorable environmental changes and the mechanism remains unclear. In this work, we proposed a potential novel pathway for ABA-mediated flower timing control in the lotus, which was explored by combining molecular, genetic, transcriptomic, biochemical, and pharmacologic approaches. We found that the aborting flower buds experienced extensive programmed cell death (PCD). The hormonal changes between the normal and aborting flower buds were dominated by abscisic acid (ABA). Seedlings treated with increasing concentrations of ABA exhibited a differential alleviating effect on flower bud abortion, with a maximal response at 80 μM. Transcriptome analysis further confirmed the changes of ABA content and the occurrence of PCD, and indicated the importance of PCD-related SNF1-related protein kinase 1 (NnSnRK1). The NnSnRK1-silenced lotus seedlings showed stronger flowering ability, with their flower:leaf ratio increased by 40%. When seedlings were treated with ABA, the expression level and protein kinase activity of NnSnRK1 significantly decreased. The phenotype of NnSnRK1-silenced seedlings could also be enhanced by ABA treatment and reversed by tungstate treatment. These results suggested that the decline of ABA content in lotus flower buds released its repression of NnSnRK1, which then initiated flower bud abortion.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tadahisa Inoue ◽  
Hiromu Kutsumi ◽  
Mayu Ibusuki ◽  
Masashi Yoneda

AbstractAlthough endobiliary radiofrequency ablation (RFA) has demonstrated considerable potential for the treatment of biliary strictures, conventional catheter RFA has several limitations. This study aimed to evaluate the feasibility of a novel cholangioscopy (CS)-guided balloon-based RFA procedure in vivo using a swine model. CS-guided balloon-RFA was performed under endoscopic retrograde cholangiography guidance at target temperatures of 60 ℃ or 70 ℃, which were maintained for 60 s. We evaluated the technical feasibility, adverse events, and histological effects associated with the procedure. Twelve sites were ablated in seven miniature pigs. The CS-guided balloon-RFA procedure was technically successful in all cases without any hindrance. Mucosal changes could be detected during RFA, and the ablation area was identified on CS. Necropsy was performed in four pigs on the same day as the procedure: the tissue samples showed coagulative necrosis, and the entire internal circumference of the bile duct was uniformly ablated. The mean lengths of the ablation area in the samples ablated at 60 °C and 70 °C were 20.64 and 22.18 mm, respectively, while the mean depths were 3.46 and 5.07 mm, respectively. The other three pigs were reared and euthanized and autopsied 35 days after the procedure. The site to be ablated had replaced the granulation tissue and fibrotic changes. No adverse events were observed in any case. CS-guided balloon-RFA appears to be a promising option for treating biliary strictures. This preliminary study could pave the way for the evaluation of this procedure in future human clinical trials.


1966 ◽  
Vol 46 (2) ◽  
pp. 141-149 ◽  
Author(s):  
Walter J. Kender ◽  
Franklin P. Eggert

A field experiment using various soil management practices showed that the most effective means to increase blueberry plant spread was through the use of a surface mulch. Peat and sawdust were of equal suitability as a mulching material influencing vegetative growth, although sawdust did result in a reduction in the number of flower buds produced when compared with peat. Mulching was associated with a higher soil moisture content than non-mulched plots.Blueberry plants growing in nitrogen-treated plots had an increased flower bud number and rhizome growth in contrast with those growing in unfertilized plots. Nitrogen fertilization was of particular benefit when applied in association with surface organic mulches.Plants growing in an undisturbed soil were more vigorous than in a homogenized or tilled soil. Sawdust was found to be detrimental to the growth of lowbush blueberry plants when incorporated into a homogenized soil.


2006 ◽  
Vol 74 (6) ◽  
pp. 3538-3546 ◽  
Author(s):  
Laura Plant ◽  
Hong Wan ◽  
Ann-Beth Jonsson

ABSTRACT The Toll-like receptors (TLRs) and the adaptor myeloid differentiation factor 88 (MyD88) are important in the innate immune defenses of the host to microbial infections. Meningococcal ligands signaling via TLRs control inflammatory responses, and stimulation can result in fulminant meningococcal sepsis. In this study, we show that the responses to nonlipooligosaccharide (non-LOS) ligands of meningococci are MyD88 dependent. An isogenic LOS-deficient mutant of the serogroup C meningococcal strain FAM20 caused fatal disease in wild type C57BL/6 mice that was not observed in MyD88−/− mice. Fatality correlated with high proinflammatory cytokine and C5a levels in serum, high neutrophil numbers in blood, and increased bacteremia at 24 h postinfection in the wild-type mice. Infection with the parent strain FAM20 resulted in fatality in 100% of the wild-type mice and 50% of the MyD88−/− mice. We conclude that both LOS and another neisserial ligand cause meningococcal sepsis in an in vivo mouse model and confirm that meningococcal LOS can act via both the MyD88- dependent and -independent pathways, while the non-LOS meningococcal ligand(s) acts only via the MyD88-dependent pathway.


Open Biology ◽  
2017 ◽  
Vol 7 (7) ◽  
pp. 170087 ◽  
Author(s):  
Yi Ting Tsai ◽  
Valentina Salzman ◽  
Matías Cabruja ◽  
Gabriela Gago ◽  
Hugo Gramajo

One of the dominant features of the biology of Mycobacterium tuberculosis , and other mycobacteria, is the mycobacterial cell envelope with its exceptional complex composition. Mycolic acids are major and very specific components of the cell envelope and play a key role in its architecture and impermeability. Biosynthesis of mycolic acid (MA) precursors requires two types of fatty acid synthases, FAS I and FAS II, which should work in concert in order to keep lipid homeostasis tightly regulated. Both FAS systems are regulated at their transcriptional level by specific regulatory proteins. FasR regulates components of the FAS I system, whereas MabR and FadR regulate components of the FAS II system. In this article, by constructing a tight mabR conditional mutant in Mycobacterium smegmatis mc 2 155, we demonstrated that sub-physiological levels of MabR lead to a downregulation of the fasII genes, inferring that this protein is a transcriptional activator of the FAS II system. In vivo labelling experiments and lipidomic studies carried out in the wild-type and the mabR conditional mutant demonstrated that under conditions of reduced levels of MabR, there is a clear inhibition of biosynthesis of MAs, with a concomitant change in their relative composition, and of other MA-containing molecules. These studies also demonstrated a change in the phospholipid composition of the membrane of the mutant strain, with a significant increase of phosphatidylinositol. Gel shift assays carried out with MabR and P fasII as a probe in the presence of different chain-length acyl-CoAs strongly suggest that molecules longer than C 18 can be sensed by MabR to modulate its affinity for the operator sequences that it recognizes, and in that way switch on or off the MabR-dependent promoter. Finally, we demonstrated the direct role of MabR in the upregulation of the fasII operon genes after isoniazid treatment.


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