Phytochemical characteristics of aerial part of Cissus quadrangularis (L) and its in-vitro inhibitory activity against leukemic cells and antioxidant properties

Background and ObjectivesCissus quadrangularis Linn, is a rich bioresource for folk and traditional medicines from ancient times till date. The present study aimed to investigate the free radical scavenging and anticancer efficacy in vitro of the ethanolic and methanolic extract from the aerial parts of Cissus quadrangularis (L).Material and MethodsIn vitro cell-free antioxidant analyses were performed for the ethanolic extract of Cissus quadrangularis (L). (EECQ) and methanolic extract of Cissus quadrangularis (L). (MECQ) using different free radical scavenging assays includes DPPH, nitric oxide, superoxide, metal chelation, and hydrogen peroxide radical scavenging assays. In vitro leukemic cytotoxic assessment by MTT assay was performed both EECQ and MECQ extract against HL-60 cell lines.ResultsStrong antioxidant effects were recorded in EECQ and MECQ in all the cell-free models. The ethanolic extract exhibited a significant dose-dependent free radical activity in comparison with methanolic extracts. The EECQ and MECQ possess pronounced anticancer efficacy against leukemic cells HL-60 with an IC₅₀ value of 36 μg/mL and 40 μg/mL respectively.ConclusionPresent data indicates the presence of marked antioxidant and anticancer behaviors in the extracts of aerial portions of Cissus quadrangularis (L). extracts. Thus, Cissus quadrangularis (L). poses as a promising safe chemopreventive plant to combat cancer.     

Variation in the methods leads to variation in the interpretation of biodiversity–ecosystem multifunctionality relationships

生物多样性常常和生态系统多功能性(生态系统同时提供多个生态系统功能的能力)正相关。然而,生物多样性与生态系统多功能性的关系是否依赖于生态系统功能的数目有诸多争议。其中,生物多样性对生态系统多功能性的影响或许不随生态系统功能数目的变化而变化,或者随生态系统功能数目的增多而增强。我们期望通过研究不同生态系统多功能性指数的统计原理来解决这些争议。 我们使用了模型模拟和一系列来自不同空间尺度(从局域到全球)和不同生物群系(温带和高寒草地、森林和干旱地)的经验数据。我们回顾了量化生态系统多功能性的三种方法,包括平均值法、加和法和阈值法。我们发现随着生态系统功能数目的增加,生物多样性与生态系统多功能性的关系要么不变,要么增强。这些结果可由平均和加和的多功能性指数的统计原理来解释。具体来讲,当利用生态系统功能的平均值计算多功能性指数时,由于多样性对多功能性的效应等于多样性对单个生态系统功能效应的平均值,所以不会随生态系统功能数目的变化而变化。同样的道理,当利用单个生态系统的加和值计算多功能性指数时,多样性的效应会随着生态系统功能数目的增加而增强。我们提出了一个改进的多功能性指数,将平均或加和多功能性指数转化为标准化的多功能性指数, 以便于对不同研究的结果进行比较。此外,我们提出了基于变量数值范围的标准化方法来解决阈值法的数学假象问题(多样性效应随生态系统功能数目的增加而增强)。我们的研究结果表明,量化多功能性指数的方法不同,结果也不同。因此,有必要加深对不同方法数理基础的理解。而标准化的多功能性指数为比较不同研究中的生物多样性与生态系统多功能性的关系提供了有效的方法。     

Liana abundance and diversity increase with rainfall seasonality along a precipitation gradient in Panama

In tropical regions, rainfall gradients often explain the abundance and distribution of plant species. For example, many tree and liana species adapted to seasonal drought are more abundant and diverse in seasonally-dry forests, characterized by long periods of seasonal water deficit. Mean annual precipitation (MAP) is commonly used to explain plant distributions across climate gradients. However, the relationship between MAP and plant distribution is often weak, raising the question of whether other seasonal precipitation patterns better explain plant distributions in seasonally-dry forests. In this study, we examine the relationship between liana abundance and multiple metrics of seasonal and annual rainfall distribution to test the hypothesis that liana density and diversity increase with increasing seasonal drought along a rainfall gradient across the isthmus of Panama. We found that a normalized seasonality index, which combines MAP and the variability of monthly rainfall throughout the year, was a significant predictor of both liana density and species richness, whereas MAP, rainfall seasonality and the mean dry season precipitation (MDP) were far weaker predictors. The strong response of lianas to the normalized seasonality index indicates that, in addition to the total annual amount of rainfall, how rainfall is distributed throughout the year is an important determinant of the hydrological conditions that favor liana proliferation. Our findings imply that changes in annual rainfall and rainfall seasonality will determine the future distribution and abundance of lianas. Models that aim to predict future plant diversity, distribution, and abundance may need to move beyond MAP to a more detailed understanding of rainfall variability at sub-annual timescales.     

Characterization of plant immunity-activating mechanism by a pyrazole derivative

ABSTRACT

A newly identified chemical, 4-{3-[(3,5-dichloro-2-hydroxybenzylidene)amino]propyl}-4,5-dihydro-1H-pyrazol-5-one (BAPP) was characterized as a plant immunity activator. BAPP enhanced disease resistance in rice against rice blast disease and expression of a defense-related gene without growth inhibition. Moreover, BAPP was able to enhance disease resistance in dicotyledonous tomato and Arabidopsis plants against bacterial pathogen without growth inhibition, suggesting that BAPP could be a candidate as an effective plant activator. Analysis using Arabidopsis sid2-1 and npr1-2 mutants suggested that BAPP induced systemic acquired resistance (SAR) by stimulating between salicylic acid biosynthesis and NPR1, the SA receptor protein, in the SAR signaling pathway.     

Plant growth regulators and Axl and immune checkpoint inhibitors from the edible mushroom Leucopaxillus giganteus

ABSTRACT

A novel compound, (R)-4-ethoxy-2-hydroxy-4-oxobutanoic acid (1), and six known compounds (2–7) were isolated from the fruiting bodies of the wild edible mushroom Leucopaxillus giganteus. The planar structure of 1 was determined by the interpretation of spectroscopic data analysis. The absolute configuration of 1 was determined by comparing specific rotation of the synthetic compounds. In the plant regulatory assay, the isolated compounds (1–7) and the chemically prepared compounds (8–10) were evaluated their biological activity against the lettuce (Lactuca sativa) growth. Compounds 1 and 3–10 showed the significant regulatory activity of lettuce growth. 1 showed the strongest inhibition activity among the all the compounds tested. In the lung cancer assay, all the compounds were assessed the mRNA expression of Axl and immune checkpoints (PD-L1, PD-L2) in the human A549 alveolar epithelial cell line by RT-PCR. Compounds 1–10 showed significant inhibition activity against Axl and/or immune checkpoint.     

Light controls stamen elongation via cryptochromes,phytochromes and COP1 through HY5 and HYH

In Arabidopsis, stamen elongation, which ensures male fertility, is controlled by the auxin response factor ARF8, which regulates the expression of the auxin repressor IAA19. Here, we uncover a role for light in controlling stamen elongation. By an extensive genetic and molecular analysis we show that the repressor of light signaling COP1, through its targets HY5 and HYH, controls stamen elongation, and that HY5 – oppositely to ARF8 – directly represses the expression of IAA19 in stamens. In addition, we show that in closed flower buds, when light is shielded by sepals and petals, the blue light receptors CRY1/CRY2 repress stamen elongation. Coherently, at flower disclosure and in subsequent stages, stamen elongation is repressed by the red and far‐red light receptors PHYA/PHYB. In conclusion, different light qualities – sequentially perceived by specific photoreceptors – and the downstream COP1–HY5/HYH module finely tune auxin‐induced stamen elongation and thus male fertility.     

PEATmoss (Physcomitrella Expression Atlas Tool): a unified gene expression atlas for the model plant Physcomitrella patens

Physcomitrella patens is a bryophyte model plant that is often used to study plant evolution and development. Its resources are of great importance for comparative genomics and evo‐devo approaches. However, expression data from Physcomitrella patens were so far generated using different gene annotation versions and three different platforms: CombiMatrix and NimbleGen expression microarrays and RNA sequencing. The currently available P. patens expression data are distributed across three tools with different visualization methods to access the data. Here, we introduce an interactive expression atlas, Physcomitrella Expression Atlas Tool (PEATmoss), that unifies publicly available expression data for P. patens and provides multiple visualization methods to query the data in a single web‐based tool. Moreover, PEATmoss includes 35 expression experiments not previously available in any other expression atlas. To facilitate gene expression queries across different gene annotation versions, and to access P. patens annotations and related resources, a lookup database and web tool linked to PEATmoss was implemented. PEATmoss can be accessed at https://peatmoss.online.uni-marburg.de