Nicotiana Plumbaginifolia Viv Research Articles

Three New Distributional Records to the Flora of Andhra Pradesh, India

The Papikonda National Park is an important wildlife area in the Eastern Ghats of Andhra Pradesh 2 spreads over 1012.86 km in East and West Godavari districts of Andhra Pradesh (Ray et al. 2020). While exploring the floral diversity of this National park, one of the authors (YM) has collected three interesting plant species from Chintur, Gokavaram and Kukunur ranges. After critical studies of the specimens with relevant literature and herbarium specimens, the specimens have been identified as Adenosma indiana (Lour.) Merr. (Plantaginaceae), Ipomoea laxiflora H.J. Chowdhery & Debta (Convolvulaceae) and Nicotiana plumbaginifolia Viv. Elench. (Solanaceae). Perusal of literature revealed that, all the three species have been not reported from Andhra Pradesh (Pullaiah, 2018). Hence these are reported here as new distributional records to the flora of Andhra Pradesh

Some important biochemical changes orchestrating flower development and senescence in Nicotiana plumbaginifolia Viv. and Petunia hybrida Vilm. flowers

ABSTRACT A comparative study of some biochemical parameters and expression patterns during flower development and senescence in Nicotiana plumbaginifolia and Petunia hybrida was carried out to ascertain the differences between the two important ornamentals. Lipid peroxidation (LPO) was found to increase throughout flower development and senescence in P. hybrida whereas in N. plumbaginifolia it decreased towards flower opening and showed a sharp increase towards senescence. Membrane stability index showed a marginal decrease towards senescence in the flowers of both the plants. Activities of the antioxidant enzymes (superoxide dismutase, catalase, ascorbate peroxidase, and lipoxygenase) increased up to the open flower stage (stage IV) and decreased thereafter towards the senescent stage in the flowers from both the plant species. The pre-senescent stages in flowers from both the plants did not show up the detection of ethylene in the petal tissues on gas chromatograph while as a climacteric rise in the ethylene concentration was exhibited by the senescent stages of both the flowers under study. mRNA-transcripts of senescence associated gene DAD1 were found to accumulate in the open flower stage (stage IV) in N. plumbaginifolia and those of ETR1 and SAG12 were found to accumulate in the open flower stage (stage IV) in P. hybrida.

Resistance of Nicotiana tabacum to Phytophthora parasitica var. nicotianae Race 0 Is Enhanced by the Addition of N. plumbaginifolia Chromosome 9 with a Slight Effect on Host Genomic Expression

ABSTRACTBlack shank is a devastating disease in tobacco production worldwide, and resistance to this disease in Nicotiana plumbaginifolia Viv. tobacco is controlled by the Php gene. The position of the Php gene on chromosomes of N. plumbaginifolia remains unclear. The tobacco line TP‐1, which was derived from N. tabacum L. cv. Yunyan87 and N. plumbaginifolia, was used in the present study to help locate the Php gene on the N. plumbaginifolia chromosomes and understand the effects of the N. plumbaginifolia chromosome addition on the genomic expression of N. tabacum. An in vitro infection test verified that TP‐1 was as resistant to Phytophthora parasitica var. nicotianae race 0 as N. plumbaginifolia and more resistant than Yunyan87. According to cytogenetic analysis, TP‐1 was identified as a monosomic alien addition line and the alien chromosome was recognized as the ninth chromosome of N. plumbaginifolia through. Thus, the P. parasitica var. nicotianae race 0 resistance gene might be Php on chromosome 9 of N. plumbaginifolia. A superficial transcriptomic analysis showed that addition of the alien chromosome slightly affected the genomic expression of the host, with only 3.32% of differentially expressed genes (DEGs) identified between TP‐1 and Yunyan87. According to Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis, most (9/13) genes classified as involved in plant–pathogen reactions, particularly five serine/threonine‐protein kinase genes, were upregulated in TP‐1. It is worth noting that flavonoid biosynthesis may be greatly downregulated in TP‐1: two genes were both downregulated in TP‐1 according to gene ontology analysis, and all 20 DEGs in the flavonoid biosynthesis pathway were downregulated in TP‐1 according to KEGG analysis.

Cleome rutidosperma DC. (Cleomaceae) and Nicotiana plumbaginifolia Viv (Solanaceae): New distributional records for Andhra Pradesh, India

Cleome rutidosperma DC. and Nicotiana plumbaginifolia Viv, collected from Palakonda, Srikakulam district and Bhavani Island, Vijayawada, Krishna district respectively are reported as new distributional records for the state of Andhra Pradesh.

NEW RECORD OF NICOTIANA PLUMBAGINIFOLIA VIV.FROM KHANDESH REGION OF MAHARASHTRA, INDIA

Nicotiana plumbaginifolia Viv.- (Solanaceae) is reported for the first time from Khandesh region of Maharashtra, India. It is reported from Jalgaon city. The present paper provides a brief description flowering and fruiting period, localities, habitat and a photo plate for easy identification.

Appearance of new weeds in Punjab

Weed monitoring and survey was conducted to detect appearance of new weed species. Ten new weed species namely Galium spurium Linn. (family Rubiaceae), Geranium nepalense Sweet (family Geraniaceae), Lamium amplexicaule Linn. (family Lamiaceae), Evolvulus nummularius (family Convolvulaceae), Euphorbia thymifolia Linn.(family Euphorbiaceae), Oenothera laciniata Hill (family Onagraceae), Soliva anthemifolia (Juss.) R. Brown (family Asteraceae), Verbesina encelioides (Cav.) Benth. and Hook. f. ex A. Gray (family Asteraceae), Nicotiana plumbaginifolia Viv. (family Solanaceae) and Portulaca oleracea L. (family Portulacaceae) have been recorded in the last decade from different places of Punjab State. Out of these, weed species namely, O. laciniata, L. amplexicaule, S. anthemifolia and G. nepalense were mainly observed inhabiting the crop fields. Three weed species namely, G. spurium, N. plumbaginifolia and V. encelioides were observed growing along roadsides, wastelands, canal banks and uncultivated areas. P. oleracea and E. thymifolia were observed growing on bunds of agricultural fields. E. nummularius is a serious weed of lawns and landscapes. These weeds have now domesticated in the studied ecological niche and may potentially harm the biodiversity of those areas.

Screening of Alleopathic Activity of the Leaves of <i>Nicotiana plumbaginifolia</i> Viv. on Some Selected Crops in Aligarh, Uttar Pradesh, India

Nicotiana plumbaginifolia Viv. is one of the fastest growing weed. It belongs to family Solanaceae. Sesquiterpenoid phytoalexins have been reported to be the chief components of secondary metabolites this family produces which are responsible for allelopathy. Every year due to its lush growth in the crop fields, N. plumbaginifolia as a weed leads to the destruction of thousand tons of crops around the globe. In the present study allelopathic effect of its leaf extract (2%, 6% and 10 %) on percent seed germination of 4 selected local crops of Aligarh (Pisum sativum L, Raphanus sativus L, Triticum aestivum L and Oryza sativa L), on its own seeds and its effects on the soil (control soil, rhizosphere soil of Nicotiana and leached soils) was studied. After eight days of incubation at room temperature, it was found that among the four plants Oryza sativa was most affected with zero percent seed germination with 2, 6 and 10 % of the leaf extract. Maximum percent of seed germination (80±10) was recorded with Pisum sativum at 2%. Nicotiana leaf extract was found autotoxic to its own seeds at 6 and 8% respectively. After 10 days of treatment, an increment of pH from control soil (pH: 7.10) to rhizosphere soil of the Nicotiana (pH: 7.28) was reported. Organic carbon, potassium and nitrogen also follow the same trend whereas the EC (0.44%) and P (13Kg/hectare) were found the maximum in leaf leached soil.

INSECTICIDAL, ANTIBACTERIAL, AND ANTIRADICAL ACTIVITY OF NICOTIANA PLUMBAGINIFOLIA VIV. (SOLANACEAE)

Objectives: Nicotiana plumbaginifolia Viv. belongs to the family Solanaceae. The present study was carried out to determine insecticidal, antibacterial, and antiradical activity of aerial parts of N. plumbaginifolia.Methods: Extraction was carried out by maceration process using methanol. Insecticidal activity was assessed, in terms of larvicidal effect, against II and IV instar larvae of Aedes aegypti. Antibacterial activity was evaluated against a panel of 7 bacteria by agar well diffusion assay. Antiradical activity was determined using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2-azinobis 3-ethylbenzothiazoline 6-sulfonate (ABTS) free radical scavenging assays.Results: The extract was found to cause dose-dependent mortality of larvae of A. aegypti. The lethal concentration 50 value of extract for II and IV instar larvae was found to be 0.41 and 0.99 mg/ml, respectively. Extract was effective in inhibiting all bacteria. Gram-positive bacteria displayed marked susceptibility when compared to Gram-negative bacteria. Bacillus cereus and Escherichia coli were susceptible to highest and least extent, respectively. Extract scavenged both DPPH radicals and ABTS radicals dose dependently. Extract scavenged ABTS radicals more efficiently (inhibitory concentration [IC50] value 13.51 μg/ml) when compared to DPPH radicals (IC50 value 17.43 μg/ml).Conclusions: The plant N. plumbaginifolia appears to be a promising resource for developing agents with insecticidal, antibacterial, and antiradical activity. The observed bioactivities could be attributed to the presence of phytochemicals which are to be isolated, characterized, and subjected for bioactivity determinations. The plant can be used to prevent arboviral diseases, infectious diseases, and oxidative damage.

Highly Oxygenated Flavonoids from the Leaves of Nicotiana plumbaginifolia (Solanaceae)

Nicotiana plumbaginifolia Viv. is an annual herb of the family Solanaceae, which grows abundantly in the weedy lands of Bangladesh. This plant possesses analgesic, antibacterial, anti-anxiety and hepatoprotective properties, and produces various phenolic compounds including flavonoids. The present study afforded determination of total phenolic and flavonoid contents, and for the first time, the isolation and characterization of highly oxygenated flavonoids, e.g., 3,3',5,6,7,8-hexamethoxy-4',5'-methylenedioxyflavone (1), 3,3',4',5',5,6,7,8-octamethoxyflavone (2, exoticin), 6,7,4',5'-dimethylenedioxy-3,5,3'-trimethoxyflavone (3) and (3,3',4',5,5',8-hexamethoxy-6,7-methylenedioxyflavone (4) from the leaves of N. plumbaginifolia. All these flavonoids are rather rare natural products, and only found in a few genera, e.g., Polygonum and Murraya. The structures of the isolated flavonoids were elucidated by comprehensive spectroscopic analyses, e.g., UV, 1H, 13C NMR, DEPT, HSQC, HMBC and MS.

Analgesic and Neuropharmacological Activities of Methanol Extract from the Leaf of Nicotiana plumbaginifolia Viv.

The aim of study was to evaluate the analgesic and neuropharmacological activities of the leaf of Nicotiana plumbaginifolia. The central analgesic activity of the methanolic extract was evaluated in Swiss Albino mice by using tail immersion, hot plate and acetic acid-induced writhing tests at 100, 200 and 400 mg/kg body weight. These tests showed significant analgesic activity of the extract compared to the standard drug, diclofenac-Na (1 mg/kg b.w.). The neuropharmacological activities were evaluated using hole cross, open field, light/dark box and elevated plus maze stage tests in mice model at 100, 200 and 400 mg/kg body weight. The results of neuropharmacological assays demonstrated potential CNS depressant activity of the extract when compared to the standard drug, diazepam (1 mg/kg b.w.)Bangladesh Pharmaceutical Journal 18(2): 85-89, 2015

English

Allelopathy is described as both beneficial and deleterious biochemical interaction between plant and weeds, and/or plant and microorganisms through the production of chemical compounds that escape into the environment and subsequently influence the growth and development of neighbouring plants. The present laboratory experimental study was conducted to evaluate the allelopathic effect of Cassia sophera (L.) on three weed plants (Chenopodium album L., Melilotus alba Medik and Nicotiana plumbaginifolia Viv.). Aqueous extracts of Cassia at 0.5, 1.0, 2.0 and 4.0% concentrations were applied to determine their effect on seed germination, seedling growth, dry biomass, leaf area, relative water content, chlorophyll and protein content of test plants under laboratory conditions. The aqueous extracts had a significant retardatory effect on seed germination of test plants which varied among species and also with the different concentrations used. Root length and shoot length of weed species decreased significantly when plants were exposed to increasing aqueous concentration (0.5, 1, 2 and 4%). The noticed reduction in dry biomass, leaf area and relative water content were also significant. Physiological parameters (total chlorophyll content and protein content) in relation to three test species (M. alba, C. album and N. plumbaginifolia) were significantly reduced with the different concentrations of aqueous extract used. From this we can predict that cassia might possess allelochemicals that causes the suppressive ability.   Key words: Allelopathy, aqueous extract, Melilotus alba, Chenopodium alba and Nicotiana plumbaginifolia.

Allelochemical stress produced by aqueous leachate of Nicotiana plumbaginifolia Viv.

The effects of aqueous leachate of Nicotiana plumbaginifolia Viv. on germination, seedling growth, amylase activity, sugar and starch contents of germinated seeds of maize (Zea mays L. cv. Uttam) were examined. Effects of leachate on photosynthetic pigments, protein content, activities of nitrate reductase and some antioxidants were also studied. Higher concentration of aqueous leachate of N. plumbaginifolia reduced the germination rate (GR). However, final germination percentage remained almost unaffected. Lower concentration of leachate stimulated the amylase activity and resulted in higher sugar content and GR. The increasing concentrations of leachate inhibited the conversion of starch into sugars. Allelochemicals decreased the amount of chlorophyll a, chlorophyll b, carotenoids, protein and nitrate reductase activity (NRA). The leachate of lower concentrations stimulated the activity of peroxidase but slight decrease was recorded in higher concentration. Superoxide dismutase and catalase exhibited concentration dependent increase except in seedlings treated with 100% concentration of leachate. Impairment of various metabolic activities due to leachate resulted in decreased root and shoot length.

The N-terminal presequence from F1-ATPase β-subunit of Nicotiana plumbaginifolia efficiently targets green fluorescent fusion protein to the mitochondria in diverse commercial crops

Approximately 10-15% of plant nuclear genes appear to encode mitochondrial proteins that are directed to mitochondria by specific targeting signals. Reports on the heterologous function of these targeting signals are generally limited to one or a few species, with an emphasis on model plants such as tobacco and Arabidopsis. Given their sequence diversity and their insufficient testing in commercially important crops (including monocotyledonous crops), the extent to which these signals can be relied on for biotechnological purposes across species remains to be established. This study provides the experimental verification of a mitochondrial signal that is functional across diverse crop species, including five monocots (sugarcane, wheat, corn, sorghum and onion) and seven dicots (cucumber, cauliflower, tomato, capsicum, pumpkin, coriander and sunflower). In all 12 crops, transient assays following microprojectile bombardment showed that the N-terminal mitochondrial presequence from F1-ATPase β-subunit (ATPase-β) of Nicotiana plumbaginifolia Viv. targeted green fluorescent fusion protein to the mitochondria. The transient assay results in sugarcane were confirmed in stably transformed root cells. The ATPase-β signal should be a useful metabolic engineering tool for directing recombinant proteins to the mitochondrial matrix in diverse plant species of commercial interest.

Mutation of the regulatory phosphorylation site of tobacco nitrate reductase results in high nitrite excretion and NO emission from leaf and root tissue.

In wild-type Nicotiana plumbaginifolia Viv. and other higher plants, nitrate reductase (NR) is regulated at the post-translational level and is rapidly inactivated in response to, for example, a light-to-dark transition. This inactivation is caused by phosphorylation of a conserved regulatory serine residue, Ser 521 in tobacco, and interaction with divalent cations or polyamines, and 14-3-3 proteins. The physiological importance of the post-translational NR modulation is presently under investigation using a transgenic N. plumbaginifolia line. This line expresses a mutated tobacco NR where Ser 521 has been changed into aspartic acid (Asp) by site-directed mutagenesis, resulting in a permanently active NR enzyme. When cut leaves or roots of this line (S(521)) were placed in darkness in a buffer containing 50 mM KNO(3), nitrite was excreted from the tissue at rates of 0.08-0.2 micromol (g FW)(-1) h(-1) for at least 5 h. For the control transgenic plant (C1), which had the regulatory serine of NR intact, nitrite excretion was low and halted completely after 1-3 h. Without nitrate in the buffer in which the tissue was immersed, nitrite excretion was also low for S(521), although 20-40 micromol (g FW)(-1) nitrate was present inside the tissue. Apparently, stored nitrate was not readily available for reduction in darkness. Leaf tissue and root segments of S(521) also emitted much more nitric oxide (NO) than the control. Importantly, NO emission from leaf tissue of S(521) was higher in the dark than in the light, opposite to what was usually observed when post-translational NR modulation was operating.

Cloning of a Wound Inducible Lycopersicon esculentum Cytochrome P450 Gene and Lack of Regeneration of Transgenic Plants with Sense or Antisense Constructs

A Lycopersicon esculentum Mill. (tomato) cDNA clone with high similarity to a Nicotiana plumbaginifolia Viv. (tobacco) cytochrome P450 gene was isolated using 5' and 3' rapid amplification of cDNA ends (RACE). The isolated cDNA (GenBank Accession No. AF249329) has an open reading frame of 1494 base pairs (bp) and encodes a protein of 498 amino acids with 75% identity to the N. plumbaginifolia cytochrome P450 (CYP72A2) and 45% to a Catharanthus roseus G. Don (Madagaskar periwinkle) CYP72A1 protein sequence. By Southern-blot analysis, one or two highly homologous genes were detected in the L. esculentum genome. Expression of the cloned P450 gene was regulated by circadian rhythm and enhanced by wounding. Leaf transcripts were detected in the light but not dark. Highest transcript levels were observed 3 hours after mechanical wounding. No increase in expression was seen in response to applications of zeatin as with the N. plumbaginifolia gene. Of the tissues analyzed, shoot tips and young leaves and fruit had the highest detectable transcript levels. Attempts to transform more than 1400 cotyledon explants of L. esculentum with sense or antisense CYP72A2 gene constructs produced no transgenic plants.

Overexpression of a 9-cis-epoxycarotenoid dioxygenase gene in Nicotiana plumbaginifolia increases abscisic acid and phaseic acid levels and enhances drought tolerance.

The plant hormone abscisic acid (ABA) plays important roles in seed maturation and dormancy and in adaptation to a variety of environmental stresses. An effort to engineer plants with elevated ABA levels and subsequent stress tolerance is focused on the genetic manipulation of the cleavage reaction. It has been shown in bean (Phaseolus vulgaris) that the gene encoding the cleavage enzyme (PvNCED1) is up-regulated by water stress, preceding accumulation of ABA. Transgenic wild tobacco (Nicotiana plumbaginifolia Viv.) plants were produced that overexpress the PvNCED1 gene either constitutively or in an inducible manner. The constitutive expression of PvNCED1 resulted in an increase in ABA and its catabolite, phaseic acid (PA). When the PvNCED1 gene was driven by the dexamethasone (DEX)-inducible promoter, a transient induction of PvNCED1 message and accumulation of ABA and PA were observed in different lines after application of DEX. Accumulation of ABA started to level off after 6 h, whereas the PA level continued to increase. In the presence of DEX, seeds from homozygous transgenic line TN1 showed a 4-d delay in germination. After spraying with DEX, the detached leaves from line TN1 had a drastic decrease in their water loss relative to control leaves. These plants also showed a marked increase in their tolerance to drought stress. These results indicate that it is possible to manipulate ABA levels in plants by overexpressing the key regulatory gene in ABA biosynthesis and that stress tolerance can be improved by increasing ABA levels.

Evidence for the involvement of tetrahydrofolate in the demethylation of nicotine by Nicotiana plumbaginifolia cell-suspension cultures.

The conversion of nicotine to nornicotine by Nicotiana plumbaginifolia Viv. cells was investigated by analysing the redistribution of label during feeding experiments with (R,S)-[2H- methyl]nicotine, (R,S)-[13C- methyl]nicotine and (R,S)-[14C- methyl]nicotine, and the results show that the N-methyl group of nicotine can be recycled into primary metabolism. Nuclear magnetic resonance (NMR) analysis of ethanolic extracts of cells grown in the presence of (R,S)-[13C- methyl]nicotine, using 1H-13C correlation spectroscopy (HMQC, HMBC), revealed the presence of [3-13C]serine and [13C- methyl]methionine. Label was also identified in a cysteinyl derivative and in several methoxylated compounds, but no evidence was obtained with either NMR or ion-trap mass spectrometry for the presence of any intermediate between nicotine and nornicotine. However, experiments with (R,S)-[14C- methyl]nicotine indicated that 70-75% of the metabolised label was released as carbon dioxide. These results are consistent with a pathway in which the oxidative hydrolysis of the nicotine methyl produces an unstable intermediate, N'-hydroxymethylnornicotine, that breaks down spontaneously to nornicotine and formaldehyde, with the formaldehyde being metabolised either directly to formate and carbon dioxide, or through the tetrahydrofolate-mediated pathways of one-carbon metabolism. However since the key intermediate, N-hydroxymethylnornicotine, could not be detected, the possibility of a direct methyl group transfer to tetrahydrofolate cannot be excluded.

A chimeric green fluorescent protein gene as an embryogenic marker in transgenic cell culture of Nicotiana plumbaginifolia Viv.

In order to check the aptitude of the green fluorescent protein (GFP) as in vivo marker of embryogenesis several variants of the GFP structural gene were expressed in Nicotiana plumbaginifolia under the transcriptional control of seed-specific unknown seed protein (USP) and legumin B4 (LeB4) gene promoters. As control the GFP genes were constitutively expressed under the control of cauliflower mosaic virus 35S promoter. Transgenic plants with a stable high level of GFP expression were selected and used to establish a direct somatic embryogenesis system derived from mesophyll protoplasts. Tissue specificity and developmental regulation of the GFP expression were investigated for all three promoter activities by Western-blotting and fluorescence microscopy. The GFP genes under the control of the USP promoter were expressed in very early stages during somatic and zygotic embryogenesis, whereas the GFP chimeric genes controlled by LeB4 promoter were expressed in late developmental stages. After the first day of in vitro protoplast culture the cells showing GFP expression controlled by the USP promoter were selected from the cells without GFP expression by fluorescence activated cell sorting. Selected cells with GFP expression were able to regenerate shoots and roots in vitro whereas selected cells without GFP expression only showed undifferentiated callus growth. Application of a stronger auxin 2,4- d as commonly used for embryogenesis induction to in vitro cultivated protoplasts resulted not only in callus growth by hindrance or interruption of the realization of morphogenetic propagation but also caused down regulation of USP promoter activity. We, therefore, conclude that the chimeric gene composed of the USP promoter and the GFP structural gene may serve as an artificial marker gene in plant embryogenesis.

Absence of arabinan in the side chains of the pectic polysaccharides strongly associated with cell walls of Nicotiana plumbaginifolia non-organogenic callus with loosely attached constituent cells.

When leaf disks from haploid plants of Nicotiana plumbaginifolia Viv. were transformed with T-DNA and cultured on shoot-inducing medium, nonorganogenic callus. designated nolac (for non-organogenic callus with loosely attached cells), appeared on approximately 7% of leaf disks. In contrast, normal callus was generated on T-DNA-transformed leaf disks from diploid plants and on non-transformed leaf disks from haploid and diploid plants. Transmission electron microscopy revealed that the middle lamellae and the cell walls of one line of mutant callus (nolac-H14) were barely stained by ruthenium red. even after demethylesterification with NaOH, whereas the entire cell wall and the middle lamella were strongly stained in normal callus. In cultures of nolac-H14 callus, the level of sugar components of pectic polysaccharides in the hemicellulose fraction was reduced and that in the culture medium was elevated, as compared with cultures of normal callus. These results indicate that pectic polysaccharides are not retained in the cell walls and middle lamellae of nolac-H14 callus. In nolac-H14, the ratio of arabinose to galactose was low in the pectic polysaccharides purified from all cell wall fractions and from the medium, in particular, in the hemicellulose fractions. The low levels of arabinofuranosyl (T-Araf, 5-Araf, 2,5-Araf, and 3,5-Araf) residues in the pectic polysaccharides of the hemicellulosic fraction of nolac-H,14 indicated that no neutral-sugar side chains, composed mainly of linear arabinan. were present in nolac-H14. Arabinose-rich pectins. which are strongly associated with cellulose-hemicellulose complexes, might play an important role in intercellular attachment in the architecture of the cell wall.

Molecular characterization of cDNAs encoding G protein α and β subunits and study of their temporal and spatial expression patterns in Nicotiana plumbaginifolia Viv.

We have isolated cDNA sequences encoding α and β subunits of potential G proteins from a cDNA library prepared from somatic embryos of Nicotiana plumbaginifolia Viv. at early developmental stages. The predicted NPGPA1 and NPGPB1 gene products are 75–98% identical to the known respective plant α and β subunits. Southern hybridizations indicate that NPGPA1 is probably a single-copy gene, whereas at least two copies of NPGPB1 exist in the N. plumbaginifolia genome. Northern analyses reveal that both NPGPA1 and NPGPB1 mRNA are expressed in all embryogenic stages and plant tissues examined and their expression is obviously regulated by the plant hormone auxin. Immunohistological localization of NPGPα1 and NPGPβ1 preferentially on plasma and endoplasmic reticulum membranes and their immunochemical detection exclusively in microsomal cell fractions implicate membrane association of both proteins. The temporal and spatial expression patterns of NPGPA1 and NPGPB1 show conformity as well as differences. This could account for not only cooperative, but also individual activities of both subunits during embryogenesis and plant development.