Presence Of Plant Growth Regulators Research Articles

Seed Priming with Ulva lactuca L. in Cultivars Grown in Martian and Lunar Regolith Analogues

Abstract As human settlements expand to lunar and Martian bases, optimizing food production in these environments becomes crucial. This study investigates the use of macroalgae, specifically Ulva lactuca L., as an affordable, sustainable approach for seed priming to enhance germination in extraterrestrial soils. The focus was on the germination and growth of Capsicum annuum L. (pepper), Lactuca sativa L. (lettuce), Cicer arietinum L. (chickpea), and Pisum sativum L. (pea) in simulated Martian and lunar regolith. Two concentrations of U. lactuca powder (0.2 and 0.4 g · L−1) were tested under controlled conditions. The study also conducted a qualitative chemical analysis of U. lactuca to identify bioactive components essential for phytohormone formation. The germination and emergence rates of the seeds in the lunar regolith were higher than those in the Martian regolith. Martian regolith's optimal treatment for pea and chickpea seed germination was 0.2 g · L−1, which also favored seedling emergence. In the lunar regolith, optimal germination rates for pea seeds were observed with both treatments and chickpea seeds. The germination percentage of lettuce seeds in the lunar regolith was higher than the control, with 0.2 g · L−1, while there was no significant difference for the other seeds. The study recommends the application of U. lactuca powder as an effective biostimulant for the examined cultivars due to the presence of plant growth regulators (PGRs) that enhance germination and seedling emergence under challenging conditions.

Screening on the Presence of Plant Growth Regulators in High Biomass Forming Seaweeds from the Ionian Sea (Mediterranean Sea)

The use of seaweed as plant biostimulants is a solution for sustainable agriculture. The present study aims to quantify and compare the presence of plant growth regulators (PGRs) in four genetically labeled macroalgae growing in the Ionian Sea. Species were selected because they produce abundant biomass, disturbing ecological equilibrium and anthropic activities. We measured the content of gibberellic acid (GA3), kinetin (KN), indoleacetic acid (IAA), abscisic acid (ABA) and indole butyric acid (IBA). The method applied was modified from the literature to obtain simultaneously different PGRs from seaweed biomass in a shorter period of time. Among results, it is notable that Hypnea corona Huisman et Petrocelli (Rhodophyta) showed higher GA3 concentration, while in Spyridia filamentosa (Wulfen) Harvey (Rhodophyta), higher KN, IBA, IAA and ABA contents were recorded. The latter species displayed an interesting profile of PGRs, with an IAA value comparable with that reported in Ascophyllum nodosum (Linnaeus) Le Jolis (Ochrophyta), which is currently used as a source of plant biostimulants in agriculture. Macroalgae thrive abundantly in nutrient-rich environments, such as anthropized coastal areas affecting human economic activities. Consequently, environmental agencies are forced to dredge algal thalli and discard them as waste. Any use of unwanted biomass as an economic product is highly desirable in the perspective of ecosustainable development.

Assessment of Plant Growth Regulators and Carbon Sources on the Germination and Growth Process of Dandelion (Taraxacum officinale G.H. Weber ex Wiggers) under In Vitro Conditions

There are several studies on the medicinal properties of dandelions (Taraxacum officinale), but few studies are aimed at understanding the in vitro germination process of this plant to improve its propagation. This research was focused on studying in vitro seed germination and development of seedlings under different carbon sources, glucose (GLU) or sucrose (SUC) and its concentrations (1.0–5.5%). Additionally, the effect of supplementation with plant growth regulators (PGRs) was studied, measuring the germination capacity, uncertainty and synchrony. Germination was promoted under low carbon source concentrations (≤2.3%), whereas higher concentrations (≥3.2%) had a detrimental effect on this process. GLU allowed the final germination percentages to be slightly better than SUC. Uniformity and synchrony values improved with the presence of PGRs. Results suggested that the best condition to assess T. officinale seed germination is in a medium containing GLU 2.3%, 0.5 mg/L 1-Naphthaleneacetic acid (NAA) and 0.5 mg/L 6-Benzylaminopurine acid (BAP). After germination, the best condition for optimal growth of T. officinale seedlings was 1.0% SUC supplemented with 0.225 mg/L of NAA and 3.0 mg/L of BAP for initial shoot development. The survival rate was 97% after greenhouse acclimatization. This new method of germination was implemented for the massive propagation of T. officinale for further medicinal studies.

Effect of 17β-estradiol on seedling and callus growth of German chamomile (Matricaria chamomilla L.)

To study the effect of 17β-estradiol on seedling growth, antioxidant enzyme activity and also, on callus induction from leaf explants of German Chamomile (Matricaria chamomilla L.), an experiment was conducted as a completely randomized design with three replications using MS medium containing different concentrations of 17β-estradiol (0, 0.01, 0.1, 1 and 10 mg/l) alone or in combination with 3 mg/l Benzylaminopurine (BAP) + 0 or 1.5 mg/l 1-naphthalene acetic acid (NAA). The results showed that 17β-estradiol at 0.01 and 0.1 mg/l increased root and shoot length and weight, respectively and at high concentration (10 mg/l) increased peroxidase, polyphenol oxidase and catalase activity of German chamomile seedlings. Also, the callus induction was observed after one to two weeks in all media, but the growth varied depending on the presence or absence of plant growth regulators and different concentrations of 17β-estradiol. Maximum callus weight was obtained in 0.01 mg/l of 17β-estradiol with about three-fold increase in comparison with the control (MS without17β-estradiol). This indicates that the 17-beta-estradiol at lower concentrations (0.01 mg/l) can significantly improve callus growth in the presence of plant growth regulators such as NAA and BAP. The results of this study indicate that using steroidal hormone 17β-estradiol can be used to optimize German chamomile cell growth under in vitro conditions.

Influence of seaweed extracts and plant growth regulators on in vitro regeneration of Lycopersicon esculentum from leaf explant

An efficient in vitro regeneration protocol was developed for tomato from leaf explant using plant growth regulators, organic elicitors, polyamines, and seaweed extracts. Initially, excised leaf explant was cultured on medium containing different concentrations of auxins viz., 2,4-dichloropheonoxyacetic acid (2,4-D; 0.5–3.0 mg L−1), picloram (Pic; 0.5–3.0 mg L−1), 1-naphthaleneacetic acid (NAA; 0.5–3.0 mg L−1), and indole-3-acetic acid (IAA; 0.5–3.0 mg L−1). The most effective auxin was tested in combination with efficient cytokinins such as kinetin (Kin; 0.5–3.0 mg L−1), 6-benzylaminopurine (BAP; 0.5–3.0 mg L−1), and thidiazuron (TDZ; 0.5–3.0 mg L−1). To achieve the best organogenic capability, different elicitors (casein hydrolysate, yeast extract, glutamine and adenine sulfate), polyamines (putrescine, spermidine, and spermine), and seaweed (Gracilaria edulis and Sargassum wightii) extracts were tested at various concentrations. Among the plant growth regulators, additives, and seaweed extracts tested, the medium supplemented with 1.5 mg L−1 Pic + 1.0 mg L−1 TDZ + 80 mg L−1 casein hydrolysate induced maximum of 28.6 shoots per organogenic callus. Rapid elongation was achieved in the medium fortified with isopentenyladenine (1.2 mg L−1) and G. edulis extract (30%) and the seaweed S. wightii extract induced rooting of elongated shoots. The presence of plant growth regulators in seaweed extracts were further confirmed by FTIR and HPLC analysis. HPLC analysis of seaweed extracts and standard plant growth regulators revealed the presence of NAA and isopentenyladenine in S. wightii. The standard chromatogram of NAA correlated with the chromatogram of G. edulis. Hence this regeneration system provides an additional platform for generating transgenic plants in an efficient manner.

In vitro regeneration of the isolated shoot apical meristem of two commercial fig cultivars ‘Sabz’ and ‘Jaami-e-Kan’

Abstract Meristem-tip of two important Iranian fig (Ficus carica L.) cultivars (‘Jaami-e-Kan’ and ‘Sabz’) were cultured under in vitro conditions to optimize the best condition for their shoot proliferation, root induction, and subsequent plantlet regeneration. Effects of explant size, culture medium (MS and B5) and different levels of BA (6-benzyladenine) in combination with 0.1 mg l−1 NAA (naphthalene acetic acid) were analyzed in the establishment of meristem cultures. The survival percentages of meristems were recorded after five weeks. Murashige and Skoog (MS) basal medium supplemented with different concentrations of BA (1, 1.5 and 2 mg l−1) and NAA (0, 0.1 and 0.5 mg l−1) was used for shoot regenerating. Half strength MS medium containing four concentrations of IBA (indole-3-butyric acid) was used for rooting. The regeneration and survival rate of cultures were significantly affected by different concentrations of BA, explant size and cultivars. The highest meristem survival was recorded from ‘Sabz’ cv., explants with the size of 0.5–0.7 mm, and culture media supplemented with 0.5 mg l−1 BA. The highest proliferation rate (2.4 shoots per micro shoot) was observed in the medium containing 2 mg l−1 BA, while the lowest length of shoots was obtained in this concentration. Furthermore, cv. ‘Sabz’ showed a higher proliferation rate (2.3 shoots per micro shoot) than cv. ‘Jaami-e-Kan’. The highest numbers of rooted micro-shoots were obtained from 1.5 mg l−1 IBA (88.3%) followed by 2 mg l−1 IBA (78.5%). Also, 2 mg l−1 IBA showed the maximum number of roots per micro shoot (14.6). These data show that the presence of plant growth regulators, besides meristem size, plays an important role in meristem culture and micropropagation of fig trees. Moreover, results of this investigation can be applied practically for true to type as well as virus free plantlets regeneration from these important Iranian fig cultivars in a short time.

In vitro multiplication of wild relatives in genus Beta conserves the invaluable threatened germplasms

Conservation of threatened plant genetic resources is vital for food security and biodiversity maintenance. Wild species of genus Beta are invaluable germplasm which could be utilized for beet breeding programs. In this study, in vitro multiplication and genotypic responses of different species in the section Beta and Corollinae were compared in presence of plant growth regulators. Following the surface sterilization, seeds were cultivated in vitro. Cotyledonary node explants were excised from the germinated young seedlings and treated with BAP, GA3 and TDZ. The obtained results demonstrated a significant difference between the genotypes in terms of in vitro shoot proliferation efficiency when subjected to BAP and GA3. Among the applied growth regulators, effect of BAP on number of multiplied shoots was the highest. Moreover, the genotypic variation in rooting was also evident when the shoots were subjected to IAA and IBA. This study is the first report of in vitro multiplication of wild species in genus Beta that could be exploited in future germplasm maintenance, gene transformation and breeding studies.

In vitro Propagation of Crassocephalum crepidioides—An Endangered African Traditional Leaf Vegetable and Molecular Analysis of Micropropagated Plants

ABSTRACTCrassocephalum crepidioides (Benth) S. Moore is an important African traditional leaf vegetable, but its production is very low and its existence threatened. An efficient and reproducible micropropagation protocol of C. crepidioides was developed from nodal stem segments of pot-grown plants. Shoot induction was obtained on Murashige and Skoog (MS) medium supplemented with benzineamino purine (BAP) alone and in combination with zeatin and naphthalene acetic acid (NAA). Elongated shoots successfully rooted on zeatin alone and in combination with indole butyric acid (IBA). Molecular stability of micropropagated plants was evaluated using random amplified polymorphic DNA (RAPD) markers. Survival of nodal segments in micropropagation medium was greater than 70% in all treatments. The presence of plant growth regulators (PGRs) in MS medium influenced shoot formation, rooting, and number of shoots and roots per explant. The best shoot formation frequency (88.7%), number of shoots per explant (3.7), and shoot length (30 mm) were from a medium containing MS supplemented with 10 mg·L−1 BAP, 15 mg·L−1 NAA, and 1.5 mg·L−1 zeatin. Frequency of root formation and survival of regenerated plants were greater on medium containing half-strength MS salt than medium fortified with full-strength MS salt. The best frequency of root formation (average 87.4%) and survival of regenerated plants (average 95.4%) were from media containing 6.0 mg·L−1 zeatin and 1.0–1.5 mg·L−1 IBA and half-strength MS salt. Micropropagated shoots with well-developed roots were acclimatized under greenhouse conditions in pots containing rich sandy loam soil (pH = 7.2). The RAPD amplification products were monomorphic in micropropagated plants and similar to those of the mother plant. No polymorphism was detected, indicating genetic uniformity of micropropagated plants. This is the first report of micropropagation of C. crepidioides, which will facilitate in vitro mass propagation, conservation, and germplasm exchange of this endangered African vegetable.

Development of in vitro propagation system for Atriplex halimus L.

Explants excised from adult shrubs were surface sterilized and cultured on Murashige and Skoog (MS) basal medium in the presence of plant growth regulators (PGRs) at different concentrations. A high multiplication rate of 7.2-fold was achieved every four weeks on MS medium supplemented with 4.44 μM BA, 0.49 μM IBA and 0.58 μM GA3. Rooting was achieved with 73% efficiency within 2-4 weeks on agar-gelled MS basal medium free of PGRs. Rooted plantlets were gradually acclimatized to field conditions over 5-6 weeks with 65% efficiency. For in vitro selection for salt tolerance, MS medium was supplemented with increasing concentrations of NaCl ranging between 25 and 1000 mM. This study has demonstrated that in vitro shoots could tolerate up to 600 mM NaCl with optimal growth at 200 mM, while higher concentrations of NaCl affected growth negatively. Growth and shoot number decreased with increasing NaCl concentration with all plantlets died at 1000 mM NaCl.

Hormonally regulated overexpression of Arabidopsis WUS and conifer LEC1 (CHAP3A) in transgenic white spruce: implications for somatic embryo development and somatic seedling growth

Adult conifers are still recalcitrant in clonal propagation despite significant advances in forest tree biotechnology. Plant regeneration through somatic embryogenesis from explants older than mature zygotic embryos is either difficult or impossible to achieve. To investigate if ectopic expression of transcription factors involved in the induction of the embryogenic process would induce somatic embryogenesis in Picea glauca (white spruce) somatic plants, we used the LEAFY-COTYLEDON1 homolog cloned from Picea mariana, CHAP3A, and Arabidopsis thaliana WUS to transform embryonal mass of P. glauca. Ectopic gene expression was induced by 17-beta-estradiol during stages of somatic embryogenesis (early embryogenesis and late embryogenesis) and somatic seedling growth in the transgenics. Of the two transcription factors, only WUS produced severe phenotypes by disrupting the development of somatic embryos on the maturation medium and inhibiting germination. However, none of the transgenes induced ectopic somatic embryogenesis even in the presence of plant growth regulators. Absolute quantitative PCR confirmed the expression of both CHAP3A and WUS in transgenic embryonal mass and in all parts of somatic seedlings. A high expression of the transgenes did not influence expression profiles of any of the ten other transcription factors tested, some of which have been known to be involved in the process of embryogenesis. Implications of these results for further work are discussed.

Kelp (Laminaria digitata) increases germination and affects rooting and plant vigour in crops and native plants from an arable grassland in the Outer Hebrides, Scotland

Kelp and other seaweeds are traditionally used in many parts of the world as a soil amendment on arable fields. Seaweeds contain biochemical compounds that can act as plant growth regulators in terrestrial plants. In a low-intensity arable grassland in northwest Scotland an organic fertilizer, kelp (Laminaria digitata) has been used for hundreds of years, due to its anticipated positive effect as a soil conditioner and provider of plant nutrients. In this study the effects of kelp on germination and rooting of crops and native plants from this area were investigated in soil-free media. Germination was studied by incubation in the presence of kelp solutions. Rooting of plant cuttings was assessed after a pulse treatment with kelp solutions, and indole-3 acetic acid (IAA) as a reference plant growth regulator. Germination percentage of Plantago lanceolata, Trifolium repens and Avena strigosa seeds increased significantly when incubated with 0.05% kelp solutions. Total root weight and the individual weight of roots produced in cuttings of Vigna radiata and P. lanceolata were significantly increased when exposed to a 0.5% solution of kelp. Plant vigour, assessed visually, decreased significantly for P. lanceolata exposed to kelp at concentrations of 0.5 and 5.0% indicating the presence of a threshold level for an inhibitory effect of kelp at these concentrations, which may be due to high salinity. The results confirmed the presence of plant growth regulators in kelp, and indicates that amendment with kelp may potentially affect plant community composition. The threshold levels where some plants responded negatively to kelp amendment were close to or lower than the theoretical concentrations of kelp in soil water at field conditions with the current doses used on the machair, indicating that care should be taken in either administering kelp at the appropriate dose or leaching out salt before application.

Activity levels of six glycoside hydrolases in apple fruit callus cultures depend on the type and concentration of carbohydrates supplied and the presence of plant growth regulators

Sucrose presence and concentration modulated in different ways and to different extents the activity of six plant glycoside hydrolases (PGHs) extracted from apple callus cultures, both in the water soluble fraction (WS-F) and in the NaCl-released fraction (NaCl-F). β-d-Glucosidase activity increased because of sucrose starvation and the addition of sucrose decreased both WS-F and NaCl-F β-d-glucosidase from calli grown in a Murashige and Skoog’s basal medium with (MSH) or without (MS0) plant growth regulators (PGRs). WS-F and NaCl-F α-l-arabinofuranosidase, NaCl-F β-d-galactosidase and NaCl-F β-d-xylosidase activity reached a maximum when 0.045 M sucrose was added to the MS0 medium with an ensuing decline at higher sucrose concentrations. α-d-Galactosidase and α-d-xylosidase activity reached a maximum when 0.045 M sucrose was supplied and did not decline significantly in 0.09 M sucrose-supplied calli. When the effects of PGR presence or absence were analysed, NaCl-F β-d-glucosidase, α-d-galactosidase, β-d-galactosidase, α-d-xylosidase and β-d-xylosidase activities were found to be higher in MS0 than in MSH. To assess whether sugar effects were sucrose-specific, other sugars (glucose, fructose, galactose, maltose, lactose, raffinose, sorbitol and mannitol) were tested, with or without PGR supplementation. In general, sugar alcohols (mannitol, sorbitol) and some monosaccharides (fructose and glucose in particular) were better inducers of NaCl-F α-l-arabinofuranosidase, β-d-galactosidase and β-d-xylosidase activity than disaccharides (sucrose, maltose, and lactose) or the trisaccharide raffinose. This trend was not widespread to all PGHs assessed since sucrose-supplemented calli displayed higher NaCl-F α-d-galactosidase than those supplemented with glucose, galactose, sorbitol or mannitol. These results show that sugars supplied to callus tissue cultures as a carbon source can also modulate PGH activity. Modulation is different for each PGH, sugar-specific and, at least in the case of sucrose, concentration-dependent. Results also suggest the existence of regulatory interactions between PGRs and sugars as part of an intricate sensing and signalling network. Combination of PGR, sugar type and concentration should be taken into account to maximize each PGH activity for further enzyme studies.

Production of lignans in callus culture of <i>Podophyllum hexandrum</i>

Purpose: Podophyllum hexandrum Royle, a source of highly valued podophyllotoxin has been subjected to heavy collection from the wild. The ever-increasing demand of podophyllum is mainly due to two semi synthetic derivatives of podophyllotoxin that is etoposide and teniposide, which are used in the treatment of various types of cancer. The anti cancer lignan derivative podophyllotoxin in Podophyllum hexandrum is biosynthesized at very low quantities in intact plant, so the biotechnological production of podophyllotoxin has been considered essential. Method: The aseptically germinated embryos of Podophyllum hexandrum were developed on solid nutrient agar slab. For the growth of callus culture, Murashigae and Skoog media (MS media)) with various concentrations of BAP, NAA and GA3 adjusted to pH 5.8 was used. Podophyllotoxin content in the alcoholic extract of calli and plant root was analysed by HPLC and HPTLC and was also compared with cultivated Podophllum hexandrum root extracts. Result: A fully defined MS medium supplemented with Naphthalene acetic acid and 6benzylaminopurine (BAP) were effective for both initiation and sustained growth of callus tissue. The relative proportion of callus was markedly influenced by presence of plant growth regulators. The amount of Podophyllotoxin obtained from callus was 0.78 and 0.79 percent as characterized by HPLC and HPTLC respectively. Conclusion: The study revealed that callus culture may be a fruitful tool for the production of Podophyllotoxin resin, an anticancer entity.

Effect of plant growth regulators and medium composition on cell growth and saponin production during cell-suspension culture of mountain ginseng (Panax ginseng C. A. mayer)

We have established cell-suspension cultures of mountain ginseng (Panax ginseng G A. Mayer), and have attempted to increase the yield of saponin by manipulating our processing method and culturing factors (e.g., media strengths; the presence of plant growth regulators or sucrose; ratios of NO+ 3/ NH- 4). Maximum biomass yield was obtained in media containing 2,4-D. However, saponin productivity was much higher in a medium comprising either IBA or NAA; 7.0 mg/L IBA was optimal for promoting both cell growth (10.0 g/L dry weight) and saponin production (7.29 mg/g DW total ginsenoside). Although the addition of cytokinins (BA and kinetin) did not affect cell growth, the level of saponin (particularly in the Rb group) was enhanced when the media were supplemented with either 0.5 mg/L BA or 0.5 mg/L kinetin. Half- and full-strength MS media were equally suitable for inducing both biomass as well as saponin production. We also investigated the effect of various concentrations of sucrose and nitrogen, and found that 30 g/L sucrose enhanced biomass yield as well as saponin content However, further increases (i.e., up to 70 g/L) led to a decrease in saponin accumulation and biomass production. Maximum growth and saponin productivity were reported from treatments with an initial nitrogen concentration of 30 mM. In general, the amount of saponin increased when the test media had high NO+ 3/ NH- 4 ratios; in fact, saponin production was greatest when nitrate was the sole nitrogen source.

Role of Nitrogen and Plant Growth Regulators in the Exudation and Accumulation of lsoflavonoids by Roots of Intact White (Lupin ( Lupinus albus L.) Plants

Summary Two isoflavonoid glycosides (7-O-β-glucopyranosides of 2′-hydroxygenistein and genistein) and up to six aglycones (2′-hydroxygenistein, genistein, wighteone, luteone, lupinisoflavone A, parvisoflavone B) were identified in root exudates and/or root extracts from white lupin ( Lupinus albus L. cv. Bac) plants. Three-d-old seedlings were cultivated for 14d on 1/2 Knop's nutrient solutions. Various treatments, differing in the form (No 3 − , NH 4 + , NH 4 N0 3 , urea) and concentration of nitrogen, and the presence of plant growth regulators in the medium were tested. Nitrogen, in all forms applied, affects both the exudation and accumulation of phenolics with the inhibitory activites arranged in the order: N0 3 − > NH 4 N0 3 > urea > NH 4 + . With higher concentration of N in the medium, the exudation of phenolics decreases. Processes of isoflavone exudation and accumulation respond differentially to nitrogen status. Exogenously applied plant growth regulators modify inhibitory effects of nitrate on the exudation and accumulation of isoflavones. Their activity depend on the type of growth regulator used (NAA, BAP, GA 3 ), its chemical structure (IAA, IBA, NAA) and concentration in the medium. Lupin isoflavones might be potential signals in legume — Rhizobium interactions. These data show a correlation between plant nutrient status and the accumulation and exudation of putative phenolic signal molecules, thus indicating the existence of possible additional controls in the regulation of nodulation process.

Evidence for the presence of plant growth regulators in commercial seaweed products

Although seaweeds and various seaweed products have been utilized in agricultural practices for many years, the precise mechanism by which they elicit their beneficial growth responses is still not fully understood. The amount of mineral nutrients in commercial preparations cannot account for the magnitude of the responses. Some other factor, such as the presence of endogenous plant growth regulators is, therefore, thought to be involved. This paper reviews the literature supporting evidence for the occurrence of plant hormones in commercial seaweed preparations.

Production of tumour-inhibitory lignans in callus cultures of Podophyllum hexandrum

Callus cultures have been established from root explants of aseptically-grown Podophyllum hexandrum seedlings. A fully defined medium based on Gamborg's B5 salts supplemented with 2/4-dichlorophenoxyacetic acid, gibberellic acid and 6-benzylaminopurine was effective for both initiation and sustained growth of callus tissue. Cultures produced anticancer lignans podophyllotoxin, 4'-demethylpodophyllotoxin and podophyllotoxin 4-O-glucoside at levels similar to those found in the expiant material as assayed by high performance liquid chromatography. The relative proportions of podophyllotoxin and 4'-demethyl-podophyllotoxin were markedly influenced by the presence of plant growth regulators. Particularly high levels of podophyllotoxin were associated with growth regulator induced tissue differentiation.