Comparative proteomics analysis of whitetop (Lepidium draba L.) seedlings in response to exogenous glucose.

In this research, a comparative proteomics approach was conducted to understand the physiological processes behind the sulforaphane formation in whitetop seedlings in response to exogenous glucose. Initially, 5-day-old whitetop seedlings were elicited by different concentrations (0, 166, 250, 277, 360 mM) of glucose for 72 h. According to the results, sulforaphane formation was influenced in a dose-dependent manner by glucose, and was maximized with the concentrations of 166 and 250 mM. Consequently, 2-dimensional gel electrophoresis was performed on the 166 mM glucose-elicited seedlings and it was shown that 25 protein spots were differentially expressed between glucose-elicited seedlings and control. Two hypothetical (were down-regulated) and 9 unique proteins (44% and 56% up- and down-regulated, respectively) were identified based on the Mass spectrometry analysis. According to the functional classification of the unique proteins, photosynthetic, chaperone, energy metabolism, signaling and sorting related proteins are marked in response to the glucose elicitation. This is the first report to successfully identify the Abscisic acid receptor PYR1-like and sorting nexin 1 isoform X1 by proteomics technique. In addition, the role of the sorting nexin 1 isoform X1 in the glucose-elicited whitetop seedling is reported for the first time.

Stomatal and pavement cell density linked to leaf internal CO2 concentration.

BACKGROUND AND AIMS: Stomatal density (SD) generally decreases with rising atmospheric CO2 concentration, Ca. However, SD is also affected by light, air humidity and drought, all under systemic signalling from older leaves. This makes our understanding of how Ca controls SD incomplete. This study tested the hypotheses that SD is affected by the internal CO2 concentration of the leaf, Ci, rather than Ca, and that cotyledons, as the first plant assimilation organs, lack the systemic signal. METHODS: Sunflower (Helianthus annuus), beech (Fagus sylvatica), arabidopsis (Arabidopsis thaliana) and garden cress (Lepidium sativum) were grown under contrasting environmental conditions that affected Ci while Ca was kept constant. The SD, pavement cell density (PCD) and stomatal index (SI) responses to Ci in cotyledons and the first leaves of garden cress were compared. (13)C abundance (δ(13)C) in leaf dry matter was used to estimate the effective Ci during leaf development. The SD was estimated from leaf imprints. KEY RESULTS: SD correlated negatively with Ci in leaves of all four species and under three different treatments (irradiance, abscisic acid and osmotic stress). PCD in arabidopsis and garden cress responded similarly, so that SI was largely unaffected. However, SD and PCD of cotyledons were insensitive to Ci, indicating an essential role for systemic signalling. CONCLUSIONS: It is proposed that Ci or a Ci-linked factor plays an important role in modulating SD and PCD during epidermis development and leaf expansion. The absence of a Ci-SD relationship in the cotyledons of garden cress indicates the key role of lower-insertion CO2 assimilation organs in signal perception and its long-distance transport.

Evidence that an evolutionary transition from dehiscent to indehiscent fruits in Lepidium (Brassicaceae) was caused by a change in the control of valve margin identity genes.

In the Brassicaceae, indehiscent fruits evolved from dehiscent fruits several times independently. Here we use closely related wild species of the genus Lepidium as a model system to analyse the underlying developmental genetic mechanisms in a candidate gene approach. ALCATRAZ (ALC), INDEHISCENT (IND), SHATTERPROOF1 (SHP1) and SHATTERPROOF2 (SHP2) are known fruit developmental genes of Arabidopsis thaliana that are expressed in the fruit valve margin governing dehiscence zone formation. Comparative expression analysis by quantitative RT-PCR, Northern blot and in situ hybridization show that their orthologues from Lepidium campestre (dehiscent fruits) are similarly expressed at valve margins. In sharp contrast, expression of the respective orthologues is abolished in the corresponding tissue of indehiscent Lepidium appelianum fruits, indicating that changes in the genetic pathway identified in A. thaliana caused the transition from dehiscent to indehiscent fruits in the investigated species. As parallel mutations in different genes are quite unlikely, we conclude that the changes in gene expression patterns are probably caused by changes in upstream regulators of ALC, IND and SHP1/2, possible candidates from A. thaliana being FRUITFULL (FUL), REPLUMLESS (RPL) and APETALA2 (AP2). However, neither expression analyses nor functional tests in transgenic plants provided any evidence that the FUL or RPL orthologues of Lepidium were involved in evolution of fruit indehiscence in Lepidium. In contrast, stronger expression of AP2 in indehiscent compared to dehiscent fruits identifies AP2 as a candidate gene that deserves further investigation.

A comparison regarding antiproliferative action between soy total extract and genistein.

The aim of this study is to make a comparison between the action of genistein and total soy extract regarding anticancer action on two different in vivo models: phytobiological test and animal model, and to see which of the two tested samples present a greater antiproliferative effect. Soybean seeds were grounded and a solvent formed of DMSO-ethanol-water in rapport 5-70-25 v/v/v was prepared. The extraction was made using an ultrasonic bath (Falc LCD Series) for 30 minutes, 59 kHz. The solvent was evaporated with a rotary evaporator at 50°C. Genistein was acquired from Extrasynthèse (France), hydroxypropyl-γ-cyclodextrin (HPGCD) from Cyclolab Hungary, 7,12-dimethylbenz[a]anthracene (DMBA), dimethylsulfoxide (DMSO), and 12-O-tetradecanoylphorbol-13-acetate (TPA) from Sigma Aldrich, Germany. Because of the poor water solubility, genistein was prepared in a complex with hydroxypropyl-γ-cyclodextrin in a molar ratio 1:2 by kneading method and total soy extract in a mass ratio 1:4 also by kneading method. Phytobiological test indicated an inhibition index over 50% in case of solutions of concentration between 8-33% in both samples, suggesting a possible antiproliferative action at a superior level. Study on C57BL/6J mice was made on which it was induced cancer with physical agents like DMBA, and it was promoted with TPA. Mice where divided in four groups: Group A - blank group, Group B - mice who received total soy extract, Group C - mice who received genistein, Group D - untreated mice. Results on animal model show that both soy total extract and genistein inhibited the initiation and promotion of chemically-induced skin tumorigenesis, but genistein had a greater success in recovering skin lesions type experimental malignant melanoma.

[Studies on the leaf epidermal features of Lepidium (Brassicaceae) from China].

OBJECTIVE: Classification and diagnostic study on Lepidiumn (Brassicaceae) from China. METHODS: Leaf epidermal mi-cromophology of 10 species of Lepidium from China were observed by using LM (light microscope) and SEM (scaning electron microscope). RESULTS: The stomatal apparatuses present both on the adaxial epidermis and the abaxial epidermis. The type of stomatal apparatuses is mainly anisocytic, rarely anomocytic and only occasionally paracytic. The leaf epidermal cells of Lepidium are usually irregular or polygonal in shape. The patterns of anticlinal walls are straight, arched, sinuolate or sinuous. The leaf features of Lepidium have better consistency. The morphology of the upper epidermis and the lower epidermis is similar, and with simple trichomes or glabrous on the leaf surface. Under SEM observation, the inner margin of the outer stomatal rim is nearly smooth or sinuolate, and the cuticular membrane of the leaf epidermis is striate. The shapes of leaf epidermal cells, the patterns of anticlinal walls, the types of stomatal ap-paratuses, the stomatal index, the stomatal size and the characters of the cuticular membrane of the leaf epidermis have important reference for differentiating species of Lepidium. CONCLUSION: The leaf epidermal features can serve as a criterion of distinguishing species in the genus Lepidium (Brassicaceae) from China, and also provide new evidence for rational use and exploitation of medical resources in Lepidium.