The impact of chemical and hormonal treatments to improve seed germination and seedling growth of Juniperus procera Hochst. ex Endi.

Purpose: Juniper (Juniperus procera) is a common forest tree species in Saudi Arabia. The decline in many populations of J. procera in Saudi Arabia is mainly due to seed dormancy and loss of natural regeneration. This study assessed the effects of chemical and hormonal treatments on seed germination and seedling growth in juniper plants. Methods: The seeds were subjected to either chemical scarification with 90% sulfuric acid and 20% acetic acid for 6 min or hormonal treatment by seed soaking in two concentrations (50 and 100 ppm) of three growth regulators, namely, indole acetic acid (IAA), gibberellins (GA3), and kinetin, for 72 h. A control group without any seed treatment was also prepared. The experiments were performed in an incubator maintained at room temperature and under a light and dark period of 12 h for 6 w. The germinated seeds for each treatment were counted and removed from the dishes. The selected germinated seeds from different treatments were planted in a greenhouse and irrigated with tap water for another 6 weeks. The hormone-treated seedlings were sprayed with their corresponding hormone concentrations 1 w after planting. Results: The highest percentage of seed germination was significantly recorded after seed soaking in 50 ppm GA3, whereas treatment with IAA (100 ppm) resulted in the best seedling growth. Seedlings treated with the three phytohormones showed a significant increase in photosynthetic pigments, total soluble sugars, proteins, percentage of oil, IAA, GA3, and kinetin contents of juniper seedlings compared with the control value, whereas abscisic acid content was decreased compared with chemical treatments. Conclusion: The investigated different treatments had an effective role in breaking seed dormancy and improving seedling growth of J. procera, which is facing a notable decline in its population worldwide. Moreover, such an effect was more pronounced in the three phytohormones that succeeded in breaking dormancy and growth of the Juniperus plant than in the other treatments.

Effects of gibberellic acid, kinetin and indole butyric acid mixture on sorghum salinity tolerance and grain yield in saline-alkali coastal zone.

The development and utilization of coastal saline-alkali lands hold significant importance in mitigating the shortage of cultivated land resources in China, enhancing the agro-ecological environment in coastal saline and alkaline areas, and ensuring national food security. We set up both pot and field trials (randomized block design) at Xinxiang experimental station of Institute of Crop Science, Chinese Academy of Agricultural Sciences (ICS-CAAS) and Dongying Yellow River Delta Modern Agricultural Research Base in Shandong Province in 2021 and 2022, respectively. The experimental materials, Jiliang 1 and Jiliang 2, underwent seed dressing with GKI composites at concentrations of 2.5 and 5 mL·kg-1. These composites, which contained the main components of gibberellin, kinetin, and indole butyric acid, were denoted as GKI2.5 and GKI5.0, respectively. The control plots (CK) received water seed dressing. The aim was to assess the regulatory effects of GKI on salt tolerance and grain sorghum yield. Compared to CK, the GKI2.5 and GKI5.0 seed dressing treatments significantly enhanced the growth and development of the two grain sorghum varieties, increased antioxidant enzyme activity and soluble protein content of sorghum leaves, while reducing leaf malondialdehyde content. Moreover, the GKI treatments increased leaf net photosynthetic rate. Under field conditions, yields of Jiliang 1 and Jiliang 2 were enhanced by an average of 17.1% and 19.1%, respectively. In conclusion, GKI seed dressing treatment effectively promoted the growth and development of sorghum under salt stress. It enhanced the antioxidant and osmoregulatory capacities of leaves, reduced the level of membrane lipid peroxidation, and improved net photosynthetic rate of leaves, which together improved the salt tolerance and sorghum yield.

Increase in ENHANCER OF SHOOT REGENERATION2 expression by treatment with strigolactone-related inhibitors and kinetin during adventitious shoot formation in ipecac.

KEY MESSAGE: Increase of ENHANCER OF SHOOT REGENERATION 2 expression was consistent to treatment with kinetin, TIS108, and KK094 in adventitious shoot formation of ipecac. Unlike many plant species, ipecac (Carapichea ipecacuanha (Brot.) L. Andersson) can form adventitious shoots in tissue culture without cytokinin (CK) treatment. Strigolactone (SL) biosynthesis and signaling inhibitors stimulate adventitious shoot formation in ipecac, suggesting their potential use as novel growth regulators in plant tissue culture, but the molecular mechanism of their action is unclear. In this study, we compared the effects of SL-related inhibitors (TIS108 and KK094) and CKs (2iP, tZ, and kinetin) on adventitious shoot formation in ipecac. Exogenously applied SL-related inhibitors and CKs stimulated adventitious shoot formation. Combinations of SL-related inhibitors and kinetin also promoted adventitious shoot formation, but without additive effects. We also analyzed the expression of CK biosynthesis genes in ipecac. TIS108 increased the expression of the ipecac homolog of ISOPENTENYL TRANSFERASE 3 (CiIPT3) but decreased that of LONELY GUY 7 homolog (CiLOG7), presumably resulting in no change in 2iP-type CK levels. KK094 and kinetin increased CiLOG7 expression, elevating 2iP-type CK levels. Among pluripotency- and meristem-related genes, TIS108, KK094, and kinetin consistently increased the expression of ENHANCER OF SHOOT REGENERATION 2 homolog (CiESR2), which has a key role in shoot regeneration, in the internodal segment region that formed adventitious shoots. We propose that CiESR2 might be a key stimulator of adventitious shoot formation in ipecac.

Kinetin inhibits hepatic stellate cell activation and induces apoptosis via interactions with the TGF-ß1/Smad signaling pathway.

Hepatic fibrosis is the pathological repair response of the liver to chronic injury; hepatic stellate cell (HSC) activation is the central link in the pathogenesis of hepatic fibrosis. Previously, we showed that kinetin, a plant cytokinin hormone, has a protective effect on CCl4-induced liver injury in mice. However, the role of kinetin in liver fibrosis remains unclear. We aimed to study these protective effects and to determine the mechanisms by which kinetin mediates HSC activation and apoptosis. For this purpose, the human HSC line LX-2 was treated with 10 ng/ml transforming growth factor-ß1 (TGF-ß1) for 24 h to stimulate activation. We found that treatment with kinetin at the sub-cytotoxic dose of 40 µg/ml for 48 h reduced the expression of the HSC activation marker α-SMA and inhibited the secretion of extracellular matrix proteins. In addition, kinetin was found to inhibit the proliferation and migration of LX-2 cells. We found that kinetin induced apoptosis in LX-2 cells by increasing the level of cleaved-caspase 3 and the Bax-to-Bcl-2 ratio. Interestingly, these effect were not observed in quiescent HSCs, suggesting that they are activation-dependent. Further study showed that kinetin attenuates activation and promotes apoptosis of LX-2 cells in vitro in part by suppressing the TGF-ß1/Smad signaling pathway.

Effect of Multi-walled Carbon Nanotubes Functionalized with Kinetin on the Development of Avena sativa.

In pioneering research, it has been documented that the CNT influences the development of plants through the balance of phytoregulators. Therefore, in this work the objective is to evaluate the effects of the CNT functionalized by non-covalent method with kinetin that have in Avena sativa. CNT was characterized by FTIR and Raman to confirm functionality. The results showed that the application of CNT with phytoregulators modified plant development.

Impacts of kinetin implementation on leaves, floral and root-related traits during seed production in hybrid rice under water deficiency.

BACKGROUND: Water deficit is one of the most significant abiotic factors affecting rice and agricultural production worldwide. In hybrid rice, cytoplasmic male sterility (CMS) is an important technique for creating high-yielding crop based on heterosis. The phytohormone kinetin (Kin) regulates cell division in plant during the early stages of grain formation, as well as flow assimilation and osmotic regulation under water stress. The present study performed to estimate the effects of irrigation intervals (irrigation each six days (I6), nine days (I9), twelve days (I12) and fifteen days (I15) against continuous flooding (CF, each three days)) and kinetin exogenously application (control, 15 mg L-1 and 30 mg L-1) on hybrid rice (L1, IR69625A; L2, G46A and R, Giza 178 R) seed production. RESULTS: Leaves traits (Chlorophyll content (CHC), relative water content (RWC), stomatal conductance (SC), Leaf temperature (LT) and transpiration rate (TR)), floral traits such as style length (SL) and total stigma length (TSL), in addition to root traits (i.e., root length (RL), root volume (RV), root: shoot ratio (RSR), root thickness (RT), root xylem vessels number (RXVN) and root xylem vessel area (RXVA) were evaluated and a significant enhancement in most traits was observed. Applying 30 mg L-1 kinetin significantly and positively enhanced all growth, floral and roots traits (RV and RXVA recorded the most increased values by 14.8% and 23.9%, respectively) under prolonging irrigation intervals, in comparison to non-treated plants. CONCLUSIONS: Subsequently, spraying kinetin exogenously on foliar could be an alternative method to reduce the harmful influences of water deficiency during seed production in hybrid rice.

Kinetin Capped Zinc Oxide Nanoparticles Improve Plant Growth and Ameliorate Resistivity to Polyethylene Glycol (PEG)-Induced Drought Stress in Vigna radiata (L.) R. Wilczek (Mung Bean).

Plants are sessile and mostly exposed to various environmental stresses which hamper plant growth, development, and significantly decline its production. Drought stress is considered to be one of the most significant limiting factors for crop plants, notably in arid and semi-arid parts the world. Therefore, the present study aimed to evaluate the potential impact of different concentrations (10, 100, and 200 µg/mL) of kinetin capped zinc oxide nanoparticles (Kn-ZnONPs) on Vigna radiata (L.) R. Wilczek under varying levels (5%, 10%, 15%) of PEG-induced drought stress. ZnONPs were synthesized by a co-precipitation method using Zinc acetate as a precursor at pH-12, incinerated to 500 °C, and kinetin was used as a surface functionalizing agent. The resulting Kn-ZnONPs were characterized by various contemporary analytical techniques, including SEM, SEM-EDS, XRD, DLS, and Zeta potential and IR spectroscopy. Crystalline Kn-ZnONPs, with a zeta potential of 27.8 mV and a size of 67.78 nm, of hexagonal wurtzite structure and vibrational stretches associated with N-H, C-O, C-N, etc., were confirmed. PEG-induced drought stress significantly reduced the growth of V. radiata by declining the chlorophyll and carotenoid contents. Moreover, a significant decrease in the levels of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), ascorbate peroxidase (APX), soluble sugar contents, proline, protein contents, phenol, and tannin were observed compared to the control. However, the exogenous application of Kn-ZnONPs ameliorated all photosynthetic parameters by up-regulating the antioxidant defense system through the promotion of SOD, POD, CAT, and lipid peroxidation levels. The biochemical parameters, such as proteins, soluble sugars, and proline, were observed to be maximum in plants treated with 200 µg/mL Kn-ZnONPs under 5% drought stress. The application of Kn-ZnONPs also enhanced the total phenol contents, flavonoid, and tannin contents. In conclusion, the findings of this study demonstrate that the exogenous application of Kn-ZnONPs provides beneficial effects to V. radiata by attenuating the damaging effects of drought stress through the up-regulation of the antioxidant defense system and osmolytes. These results suggest that Kn-ZnONPs have potential as a novel approach to improve crop productivity under drought stress conditions.

Apoptosis of Kinetin Riboside in Colorectal Cancer Cells Occurs by Promoting ß-Catenin Degradation.

Kinetin riboside is a naturally produced cytokinin that displays strong antiproliferative activity in various human cancer cells. However, the mechanism of chemoprevention in colorectal cancer cells has not been elucidated. We used a cell-based reporter system to identify kinetin riboside as an antagonist of the Wnt/ß-catenin pathway, which is aberrantly upregulated in colorectal cancer. Kinetin riboside suppressed ß-catenin response transcription (CRT) by accelerating the degradation of intracellular ß-catenin via a proteasomal degradation pathway. Pharmacological inhibition of glycogen synthase kinase-3ß did not affect CRT downregulation. Kinetin riboside decreased the intracellular ß-catenin levels in colorectal cancer cells with mutations in adenomatous polyposis coli (APC) and ß-catenin. Consistently, kinetin riboside repressed expression of c-Myc and cyclin D1, ß-catenin/T-cell factor (TCF)-dependent genes, and inhibited the proliferation of colorectal cancer cells. In addition, kinetin riboside stimulated apoptosis, as measured by an increase in annexin V-FITC-stained cells. These findings suggest that kinetin riboside exerts its anti-cancer activity by promoting ß-catenin degradation and has significant potential as a chemopreventive agent for colorectal cancer cells.

Hormonal crosstalk controls cell death induced by kinetin in roots of Vicia faba ssp. minor seedlings.

Studies of vitality/mortality of cortex cells, as well as of the concentrations of ethylene (ETH), gibberellins (GAs), indolic compounds/auxins (ICs/AUXs) and cytokinins (CKs), were undertaken to explain the hormonal background of kinetin (Kin)-regulated cell death (RCD), which is induced in the cortex of the apical parts of roots of faba bean (Vicia faba ssp. minor) seedlings. Quantification was carried out with fluorescence microscopy, ETH sensors, spectrophotometry and ultrahigh-performance liquid chromatography tandem mass spectrometry (UHPLC‒MS/MS). The results indicated that Kin was metabolized to the transport form, i.e., kinetin-9-glucoside (Kin9G) and kinetin riboside (KinR). KinR was then converted to cis-zeatin (cZ) in apical parts of roots with meristems, to cis-zeatin riboside (cZR) in apical parts of roots without meristems and finally to cis-zeatin riboside 5'-monophosphate (cZR5'MP), which is indicated to be a ligand of cytokinin-dependent receptors inducing CD. The process may be enhanced by an increase in the amount of dihydrozeatin riboside (DHZR) as a byproduct of the pathway of zeatin metabolism. It seems that crosstalk of ETH, ICs/AUXs, GAs and CKs with the cZR5'MP, the cis-zeatin-dependent pathway, but not the trans-zeatin-dependent pathway, is responsible for Kin-RCD, indicating that the process is very specific and offers a useful model for studies of CD hallmarks in plants.

Exogenous Kinetin Modulates ROS Homeostasis to Affect Heat Tolerance in Rice Seedlings.

Heat stress caused by rapidly changing climate warming has become a serious threat to crop growth worldwide. Exogenous cytokinin (CK) kinetin (KT) has been shown to have positive effects in improving salt and drought tolerance in plants. However, the mechanism of KT in heat tolerance in rice is poorly understood. Here, we found that exogenously adequate application of KT improved the heat stress tolerance of rice seedlings, with the best effect observed when the application concentration was 10-9 M. In addition, exogenous application of 10-9 M KT promoted the expression of CK-responsive OsRR genes, reduced membrane damage and reactive oxygen species (ROS) accumulation in rice, and increased the activity of antioxidant enzymes. Meanwhile, exogenous 10-9 M KT treatment significantly enhanced the expression of antioxidant enzymes, heat activation, and defense-related genes. In conclusion, exogenous KT treatment regulates heat tolerance in rice seedlings by modulating the dynamic balance of ROS in plants under heat stress.

Stem cell induction and plant regeneration are affected by medium components in maca (Lepidium meyenii Walp).

BACKGROUND: In medicinal plants, selection, reproduction and preservation of important genotypes are very necessary. Nowadays, using tissue culture and regeneration techniques of medicinal plants under in vitro conditions has been able to proliferate medicinal plants widely, which is much higher than traditional methods of vegetative propagation. Maca (Lepidium meyenii), is an industrial plant whose root is the usable part. Maca has valuable medicinal effects such as sexual enhancement and reproductive power, infertility treatment, improved sperm count and quality, anti-stress, osteoporosis prevention and more. METHODS AND RESULTS: This study was conducted to induce callus and regeneration of Maca. First, MS medium supplemented with different concentrations of Kinetin, Naphthaleneacetic acid and 2,4-Dichlorophenoxyacetic acid [0.5, 1 and 2 µM respectively] and control were compared for callus induction from root and leaves. After 38 days of incubation, the first callus appeared, after 50 days of callus induction and after 79 days regeneration occurred. The callus induction experiment was performed for the study of the effect of three explants (leaf, stem and root) and seven hormone levels. The regeneration experiment was carried out by studying the effect of three explants (leaf, stem and root) on eight levels of the hormone. The results of data analysis on callus induction showed that the effects of explants, hormones and their interactions on callus induction percentage were highly significant but not significant on callus growth rate. The results of regression analysis showed that explants, hormones and their interactions had no significant effect on regeneration percentage. CONCLUSION: Based on our results, the best medium for inducing callus was Hormone 2,4-D [2 µM] and Kinetin [0.5 µM], in which the highest percentage of callus induction was in leaf explants (62%). And the lowest were in stem (30%) and root (27%) explants. According to the comparison of the mean, the best environment for regeneration of the environment was 4 µM 6-Benzylaminopurine 2.5 + Thidiazuron, in which the highest percentage of regeneration was in leaf explant (87%) and stem (69%) and the lowest in root explant (12). %).

The Gold(I) Complex with Plant Hormone Kinetin Shows Promising In Vitro Anticancer and PPARγ Properties.

Motivated by the clinical success of gold(I) metallotherapeutic Auranofin in the effective treatment of both inflammatory and cancer diseases, we decided to prepare, characterize, and further study the [Au(kin)(PPh3)] complex (1), where Hkin = kinetin, 6-furfuryladenine, for its in vitro anti-cancer and anti-inflammatory activities. The results revealed that the complex (1) had significant in vitro cytotoxicity against human cancer cell lines (A2780, A2780R, PC-3, 22Rv1, and THP-1), with IC50 ≈ 1-5 µM, which was even significantly better than that for the conventional platinum-based drug Cisplatin while comparable with Auranofin. Although its ability to inhibit transcription factor NF-κB activity did not exceed the comparative drug Auranofin, it has been found that it is able to positively influence peroxisome-proliferator-activated receptor-gamma (PPARγ), and as a consequence of this to have the impact of moderating/reducing inflammation. The cellular effects of the complex (1) in A2780 cancer cells were also investigated by cell cycle analysis, induction of apoptosis, intracellular ROS production, activation of caspases 3/7 and disruption of mitochondrial membrane potential, and shotgun proteomic analysis. Proteomic analysis of R2780 cells treated with complex (1) and starting compounds revealed possible different places of the effect of the studied compounds. Moreover, the time-dependent cellular accumulation of copper was studied by means of the mass spectrometry study with the aim of exploring the possible mechanisms responsible for its biological effects.

Preclinical development of kinetin as a safe error-prone SARS-CoV-2 antiviral able to attenuate virus-induced inflammation.

Orally available antivirals against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are necessary because of the continuous circulation of new variants that challenge immunized individuals. Because severe COVID-19 is a virus-triggered immune and inflammatory dysfunction, molecules endowed with both antiviral and anti-inflammatory activity are highly desirable. We identified here that kinetin (MB-905) inhibits the in vitro replication of SARS-CoV-2 in human hepatic and pulmonary cell lines. On infected monocytes, MB-905 reduced virus replication, IL-6 and TNFα levels. MB-905 is converted into its triphosphate nucleotide to inhibit viral RNA synthesis and induce error-prone virus replication. Coinhibition of SARS-CoV-2 exonuclease, a proofreading enzyme that corrects erroneously incorporated nucleotides during viral RNA replication, potentiated the inhibitory effect of MB-905. MB-905 shows good oral absorption, its metabolites are stable, achieving long-lasting plasma and lung concentrations, and this drug is not mutagenic nor cardiotoxic in acute and chronic treatments. SARS-CoV-2-infected hACE-mice and hamsters treated with MB-905 show decreased viral replication, lung necrosis, hemorrhage and inflammation. Because kinetin is clinically investigated for a rare genetic disease at regimens beyond the predicted concentrations of antiviral/anti-inflammatory inhibition, our investigation suggests the opportunity for the rapid clinical development of a new antiviral substance for the treatment of COVID-19.

Photoprotective properties of new derivatives of kinetin.

The chronic exposure of skin to ultraviolet (UV) radiation causes adverse dermal reactions, such as erythema, sunburn, photoaging, and cancer, by altering several signalling pathways associated with oxidative stress, inflammation, and DNA damage. One of the possible UV light protection strategies is the use of dermal photoprotective preparations. The plant hormone kinetin (N6-furfuryladenine; KIN) exhibits antioxidant and anti-senescent effects in human cells. Topically applied KIN also reduced some of the clinical signs of photodamaged skin. To improve the biological activities of KIN, several derivatives have been recently prepared and their beneficial effects on cell viability of skin cells exposed to UVA and UVB light were screened. Two potent candidates, 6-(tetrahydrofuran-2-yl)methylamino-9-(tetrahydrofuran-2-yl)purine (HEO) and 6-(thiophen-2-yl)methylamino-9-(tetrahydrofuran-2-yl)purine (HEO6), were identified. Here the effects of KIN, its N9-substituted derivatives the tetrahydropyran-2-yl derivative of KIN (THP), tetrahydrofuran-2-yl KIN (THF), HEO and HEO6 (both THF derivatives) on oxidative stress, apoptosis and inflammation in UVA- or UVB-exposed skin cell was investigated. Human primary dermal fibroblasts and human keratinocytes HaCaT pre-treated with the tested compounds were then exposed to UVA/UVB light using a solar simulator. All compounds effectively prevented UVA-induced ROS generation and glutathione depletion in both cells. HEO6 was found to be the most potent. All compounds also reduced UVB-induced caspase-3 activity and interleukin-6 release. THP and THF exhibited the best UVB protection. In conclusion, our results demonstrated the UVA- and UVB-photoprotective potential of KIN and its derivatives. From this point of view, they seem to be useful agents for full UV spectrum protective dermatological preparations.

Kinetin induces microtubular breakdown, cell cycle arrest and programmed cell death in tobacco BY-2 cells.

Plant cells can undergo regulated cell death in response to exogenous factors (often in a stress context), but also as regular element of development (often regulated by phytohormones). The cellular aspects of these death responses differ, which implies that the early signalling must be different. We use cytokinin-induced programmed cell death as paradigm to get insight into the role of the cytoskeleton for the regulation of developmentally induced cell death, using tobacco BY-2 cells as experimental model. We show that this PCD in response to kinetin correlates with an arrest of the cell cycle, a deregulation of DNA replication, a loss of plasma membrane integrity, a subsequent permeabilisation of the nuclear envelope, an increase of cytosolic calcium correlated with calcium depletion in the culture medium, an increase of callose deposition and the loss of microtubule and actin integrity. We discuss these findings in the context of a working model, where kinetin, mediated by calcium, causes the breakdown of the cytoskeleton, which, either by release of executing proteins or by mitotic catastrophe, will result in PCD.

Assessing the genetic fidelity of somatic embryo-derived plantlets of finger millet by random amplified polymorphic DNA analysis.

Finger millet [Eleusine coracana (L.) Gaertn.] is an important cereal because of its mineral-nutrition value. With the increasing demand, there is a pressing need to conserve it through biotechnological approaches. High-frequency somatic embryogenesis from seed-derived callus of E. coracana was developed on Murashige-Skoog (MS) medium supplemented with a combination of auxins [Indole-3-acetic acid (IAA), 2,4-Dichlorophenoxy acetic acid (2,4-D)] and cytokinins [6-Benzylaminopurine (BAP), kinetin (KN)] in different concentrations, ranging from 0.1 to 5.0 mg L-1. Seeds cultured on this medium produced three different types of primary callus. Type I callus was very compact and dark brown, type II callus was light brownish and type III callus appeared whitish and light brown. All three types of calli had differential proliferation responses. Type II compact brown calli were obtained on the MS medium supplemented with 1.0 and 1.5 mg 2,4-Dichlorophenoxy acetic acid L-1 and 0.5 mg kinetin L-1. Friable yellowish embryogenic calli with a large number of somatic embryos were developed within 60 days after being transferred to auxins and cytokinin (1.0 and 1.5 mg 2,4-Dichlorophenoxy acetic acid L-1 and 0.5 mg Kinetin L-1) along with 200 mg casein hydrolysate L-1. Germination of somatic embryos on a half-strength MS medium supplemented with 0.1% Kinetin led to the development of healthy plantlets within 30 days. Genetic fingerprinting using random amplified polymorphic DNA (RAPD) revealed high levels of genetic fidelity. The study provides methods and hormonal concentrations required to develop somatic embryos in E. coracana for its genetic improvement and conservation.

Mathematical modeling and optimizing the in vitro shoot proliferation of wallflower using multilayer perceptron non-dominated sorting genetic algorithm-II (MLP-NSGAII).

Novel computational methods such as artificial neural networks (ANNs) can facilitate modeling and predicting results of tissue culture experiments and thereby decrease the number of experimental treatments and combinations. The objective of the current study is modeling and predicting in vitro shoot proliferation of Erysimum cheiri (L.) Crantz, which is an important bedding flower and medicinal plant. Its micropropagation has not been investigated before and as a case study multilayer perceptron- non-dominated sorting genetic algorithm-II (MLP-NSGAII) can be applied. MLP was used for modeling three outputs including shoots number (SN), shoots length (SL), and callus weight (CW) based on four variables including 6-benzylaminopurine (BAP), kinetin (Kin), 1-naphthalene acetic acid (NAA) and gibberellic acid (GA3). The R2 correlation values of 0.84, 0.99 and 0.93 between experimental and predicted data were obtained for SN, SL, and CW, respectively. These results proved the high accuracy of MLP model. Afterwards the model connected to Non-dominated Sorting Genetic Algorithm-II (NSGA-II) was used to optimize input variables for obtaining the best predicted outputs. The results of sensitivity analysis indicated that SN and CW were more sensitive to BA, followed by Kin, NAA and GA. For SL, more sensitivity was obtained for GA3 than NAA. The validation experiment indicated that the difference between the validation data and MLP-NSGAII predicted data were negligible. Generally, MLP-NSGAII can be considered as a powerful method for modeling and optimizing in vitro studies.

Appraisal of kinetin spraying strategy to alleviate the harmful effects of UVC stress on tomato plants.

Increasing ultraviolet (UV) radiation is causing oxidative stress that accounts for growth and yield losses in the present era of climate change. Plant hormones are useful tools for minimizing UV-induced oxidative stress in plants, but their putative roles in protecting tomato development under UVC remain unknown. Therefore, we investigated the underlying mechanism of pre-and post-kinetin (Kn) treatments on tomato plants under UVC stress. The best dose of Kn was screened in the preliminary experiments, and this dose was tested in further experiments. UVC significantly decreases growth traits, photosynthetic pigments, protein content, and primary metabolites (proteins, carbohydrates, amino acids) but increases oxidative stress biomarkers (lipid peroxidation, lipoxygenase activity, superoxide anion, hydroxyl radical, and hydrogen peroxide) and proline content. Treatment of pre-and post-kinetin spraying to tomato plants decreases UVC-induced oxidative stress by restoring the primary and secondary metabolites' (phenolic compounds, flavonoids, and anthocyanins) status and upregulating the antioxidant defense systems (non-enzymatic antioxidants as ascorbate, reduced glutathione, α-tocopherol as well as enzymatic antioxidants as superoxide dismutase, catalase, ascorbate peroxidase, glutathione peroxidase, glutathione-S-transferase, and phenylalanine ammonia-lyase). Thus, the application of Kn in optimum doses and through different modes can be used to alleviate UVC-induced negative impacts in tomato plants.

Efficient micropropagation of Thunbergia coccinea Wall. and genetic homogeneity assessment through RAPD and ISSR markers.

Thunbergia coccinea Wall. ex D. Don being a rare, ornamental and medicinal plant of India, is needed to propagate for conserving the germplasm and analyzing its phytochemical compounds in the future. A reliable protocol for direct in vitro propagation using nodal shoot meristem of T. coccinea as explant was standardized. The highest number of shoots per explant (22.17 ± 0.54) with maximum shoot length (2.36 ± 0.28) in cm was obtained in Murashige and Skoog (MS) medium supplemented with 9.70 µM of 6-furfurylaminopurine (Kinetin) and 0.053 µM of α-naphthaleneacetic acid (NAA) combination, among all the different plant growth regulators (PGR's) and concentrations tested. The aforesaid PGR's combination was optimum for axillary shoot bud induction and multiplication in T. coccinea. The best rooting was observed on the half-strength MS medium fortified with 2.68 µM NAA with the highest number of roots per shoot (3.75 ± 0.12) and maximum length (5.22 ± 0.32) in cm. All the in vitro raised plantlets were acclimatized in sterile sand and soil mixture (1:1) with a survival rate of 70% on earthen pots under greenhouse conditions. PCR-based RAPD (Random Amplified Polymorphic DNA) and ISSR (Inter-Simple Sequence Repeat) molecular markers were employed to determine the genetic homogeneity amongst the plantlets. Twelve (12) RAPD and nine (9) ISSR primers developed a total of 104 and 91 scorable bands, respectively. The band profiles of micropropagated plantlets were monomorphic to the mother, donor in vivo plant, and similarity values varied from 0.9542-1.000. The dendrogram generated through UPGMA (unweighted pair group method with arithmetic mean) showed 99% similarities amongst all tested plants confirming the genetic uniformity of in vitro raised plants.

Micropropagation of pokeweed (Phytolacca americana L.) and comparison of phenolic, flavonoid content, and antioxidant activity between pokeweed callus and other parts.

BACKGROUND: Pokeweed (Phytolacca americana L.) is regarded as an invasive plant in many parts of the world but possesses therapeutic characteristics used for antitumor and rheumatism treatment. This study investigated the effects of auxins and four explants on pokeweed callus induction. The effects of cytokinins and combinations between cytokinins and NAA on shoot and root induction were also studied. TPC, TFC and antioxidant activity of calli were screened and compared with other pokeweed plant parts. METHODS: Four explants were used to induce callus using 2,4-D and IBA at 1, 2, 3 and 4 mg/l for each auxin. Direct shoot organogenesis from nodal explants was investigated using BAP, kinetin and TDZ (1, 2 and 4 mg/l for each cytokinin). Combined effects between cytokinins and NAA at 0.1, 0.2 and 0.3 mg/l were further simultaneously estimated with root induction. Calli derived from the leaves were compared with other plant parts for TPC, TFC and antioxidant activity using the Folin-Ciocalteu, AlCl3 colorimetric assay and DPPH assays, respectively. RESULTS: Results showed that MS medium containing 2 mg/l 2,4-D induced callus formation on leaf explants that provided highest fresh and dry weights. Three types of synthetic cytokinins as kinetin, TDZ and BAP were used for direct shoot organogenesis from pokeweed nodes. MS medium containing 2 mg/l kinetin was effective in stimulating normal shoots, with the largest number of shoots and leaves and the longest shoots. The combination between cytokinins and NAA showed no positive effect on shoot and root induction from pokeweed nodal explants. For TPC and TFC determination, pokeweed seeds and leaves possessed the highest phenolic and flavonoid contents, respectively. Highest phenolic content of pokeweed seeds led to lowest IC50 by DPPH assay. Phenolic content was higher than flavonoid content. CONCLUSION: Results suggested promising conditions for callus induction. Leaf explants cultured on MS medium with 2 mg/l 2,4-D and nodal explants cultured on MS medium with 2 mg/l kinetin provided the largest number of normal shoots and leaves. NAA did not show positive effects on shoot and root induction when combined with cytokinins. Chemical constituent screening indicated that seeds and leaves provided highest TPC and TFC, respectively, while pokeweed calli contained higher phenolic than flavonoid content. This is the first report describing chemical constituent screening and antioxidant activity of calli and other parts of the pokeweed plant. Results provided significant information to further enhance bioactive compound contents of pokeweed calli using elicitation methods.