Stigma development and receptivity of two Kalanchoë blossfeldiana cultivars

Several members of the Kalanchoë genus are popular as ornamental plants. Cross-breeding and wide hybridisation are essential to continuously introduce novel traits into cultivated plant material. This study aimed to identify the major factors related to the stigma affecting cross-pollination in the Kalanchoë blossfeldiana. Pollen tube growth after pollination of K. blossfeldiana ‘Jackie’ and ‘Reese’ was examined at different stigma developmental stages. Five distinct developmental stages were identified based on changes in morphology and activity of stigmatic peroxidase. After reciprocal pollination at the five stigma developmental stages, fluorescence microscopy was used to estimate the number of pollen tubes in situ. Both cultivars had receptive stigmas from stage I to IV, which concurred with the continuous expansion of the stigma covered with exudates. No pollen tube growth was observed at stage V for both cultivars. The number of pollen tubes was significantly higher in carpels pollinated at stage III, characterized by loose arrangement of the papillae and maximal amount of exudates, compared to all other developmental stages. Stigmas showing drying exudates and absence of peroxidase exhibited a relatively decreased number of pollen tubes in situ. No pollen tubes germinated on wilting stigmas. The arrangement of the papillae, the presence of exudates and peroxidase activity affected the number of pollen tubes in cross-pollination of K. blossfeldiana cultivars ‘Jackie’ and ‘Reese’. These results will help breeders to better select the optimal time for effective pollination. The findings may be applicable for other cultivars of K. blossfeldiana and relevant for different species of Kalanchoë.     

“Antioxidant enzymes and physiological characteristics in two jerusalem artichoke cultivars under salt stress”

Russian Journal of Plant Physiology -     

Wedtrilosides A and B,two new diterpenoid glycosides from the leaves of Wedelia trilobata (L.) Hitchc. with α-amylase and α-glucosidase inhibitory activities

In the ongoing research to find new diabetes constituents from the genus Wedelia, the chemical constituent of Wedelia trilobata leaves, a Vietnamese medicinal plant species used to treat type 2 diabetes mellitus, was selected for detailed investigation. From a methanolic extract, two new ent-kaurane diterpenoids, wedtrilosides A and B (1 and 2), along with five known metabolites (3–7), were isolated from W. trilobata. The chemical structures of (1–7) were assigned via spectroscopic techniques (IR, 1D, 2D NMR and HR-QTOF-MS data) and chemical methods. The isolates were evaluated for α-amylase and α-glucosidase inhibitory activities compared to the clinical drug acarbose. Among them, compounds 4, 6, and 7 showed the most potent against α-glucosidase enzyme with IC₅₀ values of 27.54 ± 1.12, 173.78 ± 2.37, and 190.40 ± 2.01 μg/mL. While moderate inhibitory effect against α-amylase was observed with compounds 6 and 7 (with IC₅₀ = 181.97 ± 2.62 and 52.08 ± 0.56 μg/mL, respectively). The results suggested that the antidiabetic properties from the leaves of W. trilobata are not simply a result of each isolated compound, but are due to other factors such as the accessibility of polyphenolic groups to α-amylase and α-glucosidase activities.     

Somatic embryogenesis and plant recovery from mature tissues of olive cultivars (Olea europaea L.) “canino” and “moraiolo”

Summary A cyclic system of somatic embryogenesis from mature tissues of olive (Olea europaea L.) and subsequent plant recovery were developed. The primary embryos originated from morphogenetic masses derived from petioles of shoots regenerated from tissues of two micropropagated cultivars: Canino and Moraiolo. The rejuvenation acquired by the shoots by regeneration, directly from petiole tissues or indirectly from petiole callus, seems to be essential for the subsequent somatic embryogenesis induction. Cyclic embryogenesis, both from normal embryos or teratoma, was obtained on modified olive medium (OMe) plus 0.5 M; 6dimethylaminopurine, 0.44 M 6-benzylaminopurine, 0.25 M 3-indolebutyric acid and 0.42 mM cefotaxime. The production of normal embryos was higher, faster and often more clustered on a filter paper liquid medium or on a media solidified with phytagel than with agar. The capacity to produce continuous cycles of successive embryos has been maintained for over two years only in the dark, since the light inhibited embryo induction. The embryogenetic capacity was qualitatively and quantitatively enhanced by adding 0.42 mM cefotaxime. Mature embryos germinated easily by increasing the amount of liquid medium with shake culture. Although the majority of embryos appeared vitrified when transplanted to Jiffy-7 pots, they subsequently grew normally and were similar to those derived from nonvitrified embryos. The plantlets obtained from somatic embryos appeared to be morphologically similar to those produced from axillary buds.Abbreviations IBA 3-indolebutyric acid - BAP 6benzylaminopurine - TDZ thidiazuron - 2iP 6dimethylaminopurine - NAA 1-naphthaleneacetic acid - MS Murashige and Skoog (1962) - BN Bourgin and Nitsch (1967) - OM olive medium (Rugini 1984) - OMs modified olive medium - (OM) for shoot organogenesis - OMe modified olive medium - (OM) for somatic embryogenesis     

C,O – flavonoid glycosides and oleanane-type bidesmosides from Gypsophila perfoliata L. “tekirae” (Caryophyllaceae): Chemophenetic implications

In-depth characterization of specialized metabolites in the endemic Gypsophila perfoliata L. “tekirae” (G. tekirae Stef.) by liquid chromatography – quadrupol-Orbitrap mass spectrometry allowed dereplication/annotation of 22 flavonoids including 11 2″-O-pentosyl/deoxyhexosyl/hexosyl-C-hexosyl-flavones in the aerial parts and 23 gypsogenin- and quillaic acid-bidesmosides in the roots. Saponins were mainly mono-and diacetyl, and methoxycinnamoyl derivatives of 16 core structures forming isobaric isomers. Three acetylated derivatives of 2″-O-deoxyhexosyl-6-C-hexosyl-flavones are annotated for the first time in the genus Gypsophila together with five quillaic acid-based saponins. Aerial parts extract revealed prominent antioxidant and tyrosinase inhibitory activity, while roots demonstrated higher capacity against acetylcholinesterase, butyrylcholinesterase and α-glucosidase. The chemophenetic significance of acetylated 2″-O-glycosyl-6-C-hexosyl-flavones and GOTCAB saponins with methoxycinnamoyl-substituted α-chains was discussed.     

Photosynthetic responses and acclimation of two castor bean cultivars to repeated drying–wetting cycles

To investigate the responses of castor bean to repeated drying–wetting cycles (RDWC), morpho-physiological parameters of two cultivars (Jiaxiang 2 and Hangbi 8) were determined by a pot experiment under well-watered control and RDWC. RDWC inhibited plant growth and leaf development, decreased water loss rate (WLR), and enhanced leaf mass per area (LMA) and chlorophyll content as indicated by spectral reflectance indices for both cultivars. Photosynthesis was inhibited by progressive drought stress but quickly recovered after rewatering for each cycle. Both cultivars exhibit a similar pattern of acclimation to RDWC: (1) higher LMA and lower WLR, (2) increased photosynthetic capacity under drought stress with increasing cycle numbers, (3) quick recovery and over-compensation for photosynthesis after rewatering, and (4) increased chlorophyll content. Jiaxiang 2 shows a high capacity for water preservation under drought stress and an over-compensation for photosynthesis after rewatering compared with Hangbi 8.     

Crotonionosides A-G: megastigmane glycosides from leaves of Croton cascarilloides Räuschel

From the 1-BuOH-soluble fraction of a MeOH extract of leaves of Crotoncascarilloides, collected in Okinawa, Japan, seven megastigmane glycosides, named crotonionosides A-G, were isolated together with three known megastigmane glucosides, dendranthemosides A and B, and citroside A. This structures were elucidated by a combination of spectroscopic analyses, HPLC analyses, and application of the modified Mosher’s method.     

Sterols from black sea invertebrates—I. Sterols from Scyphozoa and Anthozoa (Coelenterata)

• 1.1. Rhizostoma pulmo, Aurelia aurita and Actinia equina, the most widespread representatives of Coelenterata in Black Sea have been analysed and the occurrence of 20 sterols has been found.
• 2.2. Dinosterol and demethyldinosterol as well as a number of short side chain sterols have been found in Scyphozoa for the first time.
• 3.3. The occurrence of coprostanol in marine invertebrates has been shown for the first time.
• 4.4. Five groups of sterol esters were found, containing fatty acids with different polarity.

     

Acylated flavonol glycosides and δ-truxinate derivative from the aerial parts of Lysimachia clethroides

Phytochemical investigation of the aerial parts of Lysimachia clethroides led to the isolation of a new acylated flavonol glycoside (1) and a new δ-truxinate derivative (2), together with three known acylated flavonol glycosides. The structures of the new compounds were determined by spectroscopic methods and chemical evidence as quercetin-3-O-β-d-(6-O-Z-p-coumaroyl)glucopyranoside (1) and monomethyl 3,3′,4,4′-tetrahydroxy-δ-truxinate (2), respectively. All of the isolates were evaluated for their in vitro inhibitory activity against aldose reductase.     

Haplomyrtin and (−)-haplomyrfolin: two lignans from haplophyllum myrtifolium

Haplomyrtin, a new 1-aryl-2-3-naphthalide lignan, and (−)-haplomyrfolin, a new dibenzylbutyrolactone lignan, have been obtained from Turkish Haplophyllum myrtifolium.     

Oleanane-type triterpene saponins from the bark of Aralia elata and their NF-κB inhibition and PPAR activation signal pathway

Two new oleanane-type triterpene saponins, tarasaponin IV (1) and elatoside L (2), and four known; stipuleanoside R(2) (3), kalopanax-saponin F (4), kalopanax-saponin F methylester (5), and elatoside D (6) were isolated from the bark of Aralia elata. Kalopanax-saponin F methyl ester was isolated from nature for the first time. Their chemical structures were elucidated using the chemical and physical methods as well as good agreement with those of reported in the literature. Oleanane-type triterpene saponins are the main component of A. elata. All compounds were investigated the anti-inflammatory activity. We measured their inhibition of NF-κB and activation of PPARs activities in HepG2 cells using luciferase reporter system. As results, compounds 2 and 4 were found to inhibit NF-κB activation stimulated by TNFα in a dose-dependent manner with IC(50) values of 4.1 and 9.5 μM, respectively, when compared with that of positive control, sulfasalazine (0.9 μM). Compounds 2 and 4 also inhibited TNFα-induced expression of iNOS and COX-2 mRNA. Furthermore, compounds 1-6 were evaluated PPAR activity using PPAR subtype transactivation assays. Among of them, compounds 4-6 significantly increased PPARγ transactivation. However, compounds 4-6 did not activate in any other PPAR subtypes.