Band 73, Heft 5-6

Finger millet ( Eleusine coracana L. Gaertn., 2n=36) is one of the most important minor crops, commonly known as ‘ragi’ and used as a staple food grain in more than 25 countries including Africa and south Asia. Twenty-seven accessions of ragi were collected from different parts of India and were evaluated for morpho-genetic diversity studies. Simple sequence repeat (SSR) and random amplified polymorphic DNA (RAPD) markers were used for assessment of genetic diversity among 27 genotypes of E. coracana . High degree of similarity (90%) was obtained between ‘IC49979A’ and ‘IC49974B’ genotypes, whereas low level of similarity (9.09%) was found between ‘IC204141’ and ‘IC49985’ as evident in morphological and DNA markers. A total of 64 SSR and 301 RAPD amplicons were produced, out of which 87.50% and 77.20% DNA fragments showed polymorphism, respectively. The clustering pattern obtained among the genotypes corresponded well with their morphological and cytological data with a monophyletic origin of this species which was further supported by high bootstrap values and principal component analysis. Cluster analysis showed that ragi accessions were categorised into three distinct groups. Genotypes IC344761, IC340116, IC340127, IC49965 and IC49985 found accession specific in RAPD and SSR markers. The variation among ragi accessions might be used as potential source of germplasm for crop improvement.

Monoterpenes are common constituents of essential oils produced by plants. Although it has been reported that monoterpenes enhanced the heat tolerance of plants, the mechanism has not been elucidated. Here, we tested whether 13 monoterpenes promoted the heat shock response (HSR) in Arabidopsis . To assess the HSR-inducing activity of monoterpenes, we produced transgenic Arabidopsis , which has the β-glucuronidase gene driven by the promoter of a small heat shock protein ( HSP17.6C-CI ) gene. Results indicated that two monocyclic and four bicyclic monoterpenes showed HSR-inducing activities using the reporter gene system. In particular, (−)-perillaldehyde, which is a monocyclic monoterpene, demonstrated the most potent HSR-inducing activity. (−)-Perillaldehyde significantly inhibited the reduction of chlorophyll content by heat shock in Arabidopsis seedlings. Our previous study indicated that chemical HSR inducers such as geldanamycin and sanguinarine inhibited the activity of plant chaperones in vitro. (−)-Perillaldehyde also inhibited chaperone activity, indicating that it might promote the expression of heat shock protein genes by inhibiting chaperones in the plant cell.

Garcinia mangostana L. (the queen of fruits, mangosteen, family Guttiferae) is a wealthy source of xanthones. The CHCl 3 soluble fraction of the air-dried pericarps of G. mangostana provided a new xanthone: mangostanaxanthone VII ( 5 ), along with four known xanthones: mangostanaxanthones I ( 1 ) and II ( 2 ), gartanin ( 3 ) and γ-mangostin ( 4 ). The structural verification of these metabolites was achieved by different spectral techniques, including UV, IR, 1D and 2D NMR and HRESIMS. The new metabolite was assessed for cytotoxic potential, using sulforhodamine B (SRB) assay towards the A549 and MCF-7 cancer cell lines. Moreover, its antimicrobial effects were evaluated against various bacterial and fungal strains, using agar disc diffusion assay. Mangostanaxanthone VII showed moderate cytotoxic activity against the A549 and MCF7 cell lines with IC 50 s 26.1 and 34.8 μM, respectively, compared with doxorubicin (0.74 and 0.41 μM, respectively).

As an important plateau cereal crop, hulless barley is the principal food for the Tibetan people in China. ADP-glucose pyrophosphorylase (AGPase) is considered as the key enzyme for starch biosynthesis in plants. In this study, cDNAs encoding the small subunit (SSU I) and large subunit (LSU I) of AGPase were isolated from hulless barley. The results showed that SSU I and LSU I were 1438 and 1786 bp in length with a complete open reading frame (ORF) of 1419 and 1572 bp. The ORF-encoded polypeptides of 472 and 523 amino acids were having calculated molecular masses of 52.01 and 58.23 kDa, and the pI values were 5.59 and 6.30. In addition, phylogenetic analysis showed that SSU I and LSU I had the same phylogenetic trends with some species. Furthermore, expression levels in different growth periods and tissues of two hulless barley varieties were analyzed by quantitative reverse transcription-polymerase chain reaction. Gene expression levels of SSU I and LSU I were consistent with the total starch accumulation rate in endosperm. In conclusion, our data confirmed that SSU I and LSU I played an important role in hulless barley starch synthesis.

Fifteen pyrrole alkaloids were isolated from the Red Sea marine sponge Stylissa carteri and investigated for their biological activities. Four of them were dibrominated [(+) dibromophakelline, Z -3-bromohymenialdisine, (±) ageliferin and 3,4-dibromo-1 H -pyrrole-2-carbamide], nine compounds were monobrominated [(−) clathramide C, agelongine, (+) manzacidin A, (−) 3-bromomanzacidin D, Z -spongiacidin D, Z -hymenialdisine, 2-debromostevensine, 2-bromoaldisine and 4-bromo-1 H -pyrrole-2-carbamide)] and finally, two compounds were non-brominated derivatives viz., E -debromohymenialdisine and aldisine. The structure elucidations of isolated compounds were based on 1D & 2D NMR spectroscopic and MS studies, as well as by comparison with literature. In-vitro, Z -spongiacidin D exhibited a moderate activity on (ARK5, CDK2-CycA, CDK4/CycD1, VEGF-R2, SAK and PDGFR-beta) protein kinases. Moreover, Z -3-bromohymenialdisine showed nearly similar pattern. Furthermore, Z -hymenialdisine displayed a moderate effect on (ARK5 & VEGF-R2) and (−) clathramide C showed a moderate activity on AURORA-A protein kinases. While, agelongine, (+) manzacidin A, E -debromohymenialdisine and 3,4-dibromo-1 H -pyrrole-2-carbamide demonstrated only marginal inhibitory activities. The cytotoxicity study was evaluated in two different cell lines. The most effective secondary metabolites were (+) dibromophakelline and Z -3-bromohymenialdisine on L5178Y. Finally, Z -hymenialdisine, Z -3-bromohymenialdisine and (±) ageliferin exhibited the highest cytotoxic activity on HCT116. No report about inhibition of AURORA-A and B by hymenialdisine/hymenialdisine analogs existed and no reported toxicity of ageliferin existed in literature.

Despite the well-documented benefits of Combretum fragrans in Cameroon, only few scientific works have been done on it. In this study we isolated eight compounds from the leaves extract of C. fragrans : velutin ( 1 ), belamcanidin ( 2 ), cirsilineol ( 3 ), cirsimaritin ( 4 ), 3β-acetoxy-20,24-epoxy-11,25-hydroxy-dammarane ( 5 ), combretin A ( 6 ), combretin B ( 7 ) and a mixture of arjunolic acid ( 8a ) and asiatic acid ( 8b ). Compounds 6 and 7 presented potent anti-inflammatory, antioxidant and antidiabetic activities. Compounds 1 , 3 , 5 and the mixture of 8a and 8b were significantly active, and compounds 2 and 4 presented moderate activity for reactive oxygen species inhibitory and free-radical scavenging. All compounds were isolated using chromatographic techniques; their structures were elucidated by spectroscopic techniques and their spectroscopic data compared with those of the literature. Anti-inflammatory activity was evaluated via the oxidative burst assay using a luminol-amplified chemiluminescence technique, antioxidant activity by free-radical scavenging activity (DPPH) and antidiabetic activity via α-glucosidase inhibition. All of the isolated compounds ( 1–8 ) were reported to exhibit significant antioxidant activity. Compounds 1 , 3 , and 5–8 exhibited potent chemiluminescence inhibition effect, and only compounds 6 and 7 inhibited α-glucosidase. Thus, C. fragrans can be used as an effective natural source of anti-inflammatory, antioxidant and antidiabetic compounds.

Photodynamic inactivation (PDI) has been featured as an effective strategy in the treatment of acute drug-resistant infections. The efficiency of PDI was evaluated against three periodontal pathogenic bacteria that were tested as drug-resistant strains. In vitro studies were performed with four water-soluble cationic Zn(II) phthalocyanines (ZnPc 1–4 ) and irradiation of a specific light source (light-emitting diode, 665 nm) with three doses (15, 36 and 60 J/cm 2 ). The well detectable fluorescence of ZnPcs allowed the cellular imaging, which suggested relatively high uptakes of ZnPcs into bacterial species. Complete photoinactivation was achieved with all studied ZnPc 1–4 for Enterococcus faecalis ( E. faecalis ) at a light dose of 15 J/cm 2 . The photodynamic response was high for Prevotella intermedia ( P. intermedia ) after the application of 6 μM of ZnPc 1 and a light dose of 36 J/cm 2 and for 6 μM of ZnPc 2 at 60 J/cm 2 . P. intermedia was inactivated with ZnPc 3 (4 log) and ZnPc 4 (2 log) with irradiation at an optimal dose of 60 J/cm 2 . Similar photoinactivation results (2 log) were achieved for Aggregatibacter actinomycetemcomitans ( A. actinomycetemcomitans ) treated with 6 μM ZnPc 1 and ZnPc 2 at a light dose of 60 J/cm 2 . The study suggested that PDI with quaternized Zn(II) phthalocyanines and specific light irradiation appears to be a very useful antimicrobial strategy for effective inactivation of drug-resistant periodontal pathogens.

Adventitious roots (ARs) of lotus ( Nelumbonucifera Gaertn.) play a critical role in water and nutrient uptake. We found that exogenously applied 10-μM indole-3-acetic acid (IAA) promoted the formation of ARs, while 150-μM IAA significantly inhibited the emergence of ARs. However, little is known about these different responses to various concentrations of IAA at the molecular level. This study, therefore, examined the gene expression profiling in four libraries treated with 10- and 150-μM IAA based on the high-throughout tag sequencing technique. Approximately 2.4×10 7 clean tags were obtained after the removal of low-quality tags from each library respectively, among which about 10% clean tags were unambiguous tag-mapped genes to the reference genes. We found that some genes involved in auxin metabolism showed a similar tendency for expression in the A/CK and C/CK libraries, while three genes were enhanced their expression only in the A/CK libraries. Two transcription factors including B3 domain-containing protein At2g36080-like and trihelix transcription factor were up-regulated for transcriptional level in the A/C libraries. The expressions of six important genes related to AR formation were significantly different in the A/CK and C/CK libraries. In summary, this study provides a comprehensive understanding of gene expression regulated by IAA involved in AR formation in lotus.

The antibacterial-guided investigation of the stem bark extract of Pseudocedrela kotschyi led to the isolation of a new secotirucallane triterpene derivative: 4-hydroxy-3,4-secotirucalla-7,24-dien-3,21-dioic acid ( 1 ), together with the known one: 3,4-secotirucalla-4(28),7,24-trien-3,21-dioic acid ( 2 ) and 3-methyl ester 3,4-secotirucalla-4(28),7,24-trien-3,21-dioic ( 3 ). The structures of the isolated compounds were elucidated on the basis of extensive 1D- and 2D-NMR spectroscopy. Extracts, fractions and compounds ( 1–3 ) were tested in vitro for antibacterial activity against two Gram positive bacteria ( Bacillus subtilis and Staphylococcus aureus ATCC 25923), and two Gram negative bacteria ( Escherichia coli S2(1) and Pseudomonas aeruginosa ). The MeOH extract and the Hex/CH 2 Cl 2 (70:30) fraction showed significant levels of activity (MIC=64– 256 μg/mL) compared with the two reference drugs [ciprofloxacin: MIC (0.5–1 μg/mL) and amoxicillin: MIC (1–128 μg/mL)]. Moreover, the compound 2 isolated from this Hex/CH 2 Cl 2 (70:30) fraction had the greatest potential value against S. aureus , E. coli and P. aeruginosa , with minimum inhibitory concentrations (MIC) ranging from 4–16 μg/mL.

Plant growth-promoting bacteria that are also capable of suppressing plant pathogenic fungi play an important role in sustainable agriculture. There is a critical need for conducting research to discover, characterize and evaluate the efficacy of new strains of such bacteria in controlling highly aggressive plant pathogens. In this study, we isolated endophytic bacteria from medicinal plants of Bangladesh and evaluated their antagonistic capacity against an important phytopathogenic fungus Sclerotinia sclerotiorum . Growth-promoting effects of those isolates on cucumber and rice seedlings were also assessed. Among 16 morphologically distinct isolates, BDR-2, BRtL-2 and BCL-1 significantly inhibited the growth of S. sclerotiorum through induction of characteristic morphological alterations in hyphae and reduction of mycelial dry weight. When cucumber and rice seeds were treated with these endophytic bacteria, seven isolates (BCL-1, BDL-1, BRtL-2, BRtL-3, BDR-1, BDR-2 and BBoS-1) enhanced seed germination, seedling vigor, seedling growth and number of roots per plant at a varying level compared to untreated controls. All isolates produced high levels of indole-3-acetic acid (6 to 63 μg/mL) in vitro. Two most potential isolates, BDR-2 and BRtL-2, were identified as Bacillus amyloliquefaciens and B. subtilis , respectively, based on the 16S rRNA gene sequencing. These results suggest that endophytic Bacillus species from native medicinal plants have great potential for being used as natural plant growth promoter and biopesticides in sustainable crop production.