Salt-stress-responsive chloroplast proteins in <Emphasis Type="Italic">Brassica juncea</Emphasis> genotypes with contrasting salt tolerance and their quantitative PCR analysis

Brassica juncea is mainly cultivated in the arid and semi-arid regions of India where its production is significantly affected by soil salinity. Adequate knowledge of the mechanisms underlying the salt tolerance at sub-cellular levels must aid in developing the salt-tolerant plants. A proper functioning of chloroplasts under salinity conditions is highly desirable to maintain crop productivity. The adaptive molecular mechanisms offered by plants at the chloroplast level to cope with salinity stress must be a prime target in developing the salt-tolerant plants. In the present study, we have analyzed differential expression of chloroplast proteins in two Brassica juncea genotypes, Pusa Agrani (salt-sensitive) and CS-54 (salt-tolerant), under the effect of sodium chloride. The chloroplast proteins were isolated and resolved using 2DE, which facilitated identification and quantification of 12 proteins that differed in expression in the salt-tolerant and salt-sensitive genotypes. The identified proteins were related to a variety of chloroplast-associated molecular processes, including oxygen-evolving process, PS I and PS II functioning, Calvin cycle and redox homeostasis. Expression analysis of genes encoding differentially expressed proteins through real time PCR supported our findings with proteomic analysis. The study indicates that modulating the expression of chloroplast proteins associated with stabilization of photosystems and oxidative defence plays imperative roles in adaptation to salt stress.     

Attenuation of pattern recognition receptor signaling is mediated by a MAP kinase kinase kinase

Pattern recognition receptors (PRRs) play a key role in plant and animal innate immunity. PRR binding of their cognate ligand triggers a signaling network and activates an immune response. Activation of PRR signaling must be controlled prior to ligand binding to prevent spurious signaling and immune activation. Flagellin perception in Arabidopsis through FLAGELLIN‐SENSITIVE 2 (FLS2) induces the activation of mitogen‐activated protein kinases (MAPKs) and immunity. However, the precise molecular mechanism that connects activated FLS2 to downstream MAPK cascades remains unknown. Here, we report the identification of a differentially phosphorylated MAP kinase kinase kinase that also interacts with FLS2. Using targeted proteomics and functional analysis, we show that MKKK7 negatively regulates flagellin‐triggered signaling and basal immunity and this requires phosphorylation of MKKK7 on specific serine residues. MKKK7 attenuates MPK6 activity and defense gene expression. Moreover, MKKK7 suppresses the reactive oxygen species burst downstream of FLS2, suggesting that MKKK7‐mediated attenuation of FLS2 signaling occurs through direct modulation of the FLS2 complex.     

O‐GlcNAcylation of protein kinase A catalytic subunits enhances its activity: a mechanism linked to learning and memory deficits in Alzheimer's disease

Alzheimer's disease (AD) is characterized clinically by memory loss and cognitive decline. Protein kinase A (PKA)‐CREB signaling plays a critical role in learning and memory. It is known that glucose uptake and O‐GlcNAcylation are reduced in AD brain. In this study, we found that PKA catalytic subunits (PKAcs) were posttranslationally modified by O‐linked N‐acetylglucosamine (O‐GlcNAc). O‐GlcNAcylation regulated the subcellular location of PKAcα and PKAcβ and enhanced their kinase activity. Upregulation of O‐GlcNAcylation in metabolically active rat brain slices by O‐(2‐acetamido‐2‐deoxy‐d ‐glucopyranosylidenamino) N‐phenylcarbamate (PUGNAc), an inhibitor of N‐acetylglucosaminidase, increased the phosphorylation of tau at the PKA site, Ser214, but not at the non‐PKA site, Thr205. In contrast, in rat and mouse brains, downregulation of O‐GlcNAcylation caused decreases in the phosphorylation of CREB at Ser133 and of tau at Ser214, but not at Thr205. Reduction in O‐GlcNAcylation through intracerebroventricular injection of 6‐diazo‐5‐oxo‐l ‐norleucine (DON), the inhibitor of glutamine fructose‐6‐phosphate amidotransferase, suppressed PKA‐CREB signaling and impaired learning and memory in mice. These results indicate that in addition to cAMP and phosphorylation, O‐GlcNAcylation is a novel mechanism that regulates PKA‐CREB signaling. Downregulation of O‐GlcNAcylation suppresses PKA‐CREB signaling and consequently causes learning and memory deficits in AD.     

Ethnobotany of the Balti community,Tormik valley,Karakorum range,Baltistan, Pakistan

Background

Limited health facilities and malnutrition are major problems in the Karakorum Range of Northern Pakistan, often resulting in various human disorders. Since centuries, however, local communities in these areas have developed traditional methods for treating various ailments and local foods capes that can be significant for devising public health and nutritional policies. This study was intended to document the ethnobotanical knowledge of the local peoples in the Tormik Valley, especially in the medical and food domains.

Methods

Field trips were undertaken in 14 different villages of the study area from 2010 to 2012. Ethnobotanical data were gathered using semi-structured interviews and group conversation with 69 informants. Details about local uses of plant species were recorded along with demographic characteristics of the visited communities. Relative frequency citation index (RFCi) and preference ranking index (PRi) tools were applied to determine the cultural significance of the reported species.

Results

Sixty-three plant species, with a predominance of Asteraceae and Fabaceae family members, as well as their detailed folk uses were documented. Forty-three percent of the species were used to treat various diseases, 21 % were consumed as wild fruits and vegetables and 53 % of the species had multipurpose applications. Thymus linearis Benth, Hippophae rhamnoides ssp. turkestanica L. and Convolvulus arvensis L. were found to be the most utilized medicinal plant species, i.e. those with significant RFCi values (0.54, 0.51 and 0.48, respectively). Betula utilis D. Don was the most versatile taxon (seven different ways of utilization); being this species a common and easily accessible subalpine tree and then under anthropogenic pressure, the implementation of concrete strategies aimed at its in-situ and ex-situ conservation is strongly recommended.

Conclusion

The valleys in the Karakorum Mountains in the Northern Pakistan host significant Traditional Knowledge on local food and medicinal plant species, which need to be reconsidered and cautiously re-evaluated by ethnopharmacologists, and public health/nutrition actors. Furthermore, germane trans-disciplinary investigations are suggested to ensure the dynamic conservation of precious local knowledge systems, as well as plant diversity in Pakistani mountain regions.

     

Isolation of Ceramides from Tagetes patula L. Yellow Flowers and Nematicidal Activity of the Fractions and Pure Compounds against Cyst Nematode,Heterodera zeae

Investigation of yellow flower extract of Tagetes patula L. led to the identification of an aggregate of five phytoceramides. Among them, (2R)‐2‐hydroxy‐N‐[(2S,3S,4R,8E)‐1,3,4‐trihydroxyicos‐8‐en‐2‐yl]icosanamide, (2R)‐2‐hydroxy‐N‐[(2S,3S,4R,8E)‐1,3,4‐trihydroxyicos‐8‐en‐2‐yl]heneicosanamide, (2R)‐2‐hydroxy‐N‐[(2S,3S,4R,8E)‐1,3,4‐trihydroxyicos‐8‐en‐2‐yl]docosanamide, and (2R)‐2‐hydroxy‐N‐[(2S,3S,4R,8E)‐1,3,4‐trihydroxyicos‐8‐en‐2‐yl]tricosanamide were identified as new compounds and termed as tagetceramides, whereas (2R)‐2‐hydroxy‐N‐[(2S,3S,4R,8E)‐1,3,4‐trihydroxyicos‐8‐en‐2‐yl]tetracosanamide was a known ceramide. A steroid (β‐sitosterol glucoside) was also isolated from the subsequent fraction. The structures of these compounds were determined on the basis of spectroscopic analyses, as well as chemical method. Several other compounds were also identified by GC/MS analysis. The fractions and some commercial products, a ceramide HFA, β‐sitosterol, and stigmasterol were evaluated against an economically important cyst nematode, Heterodera zeae. Ceramide HFA showed 100 % mortality, whereas, β‐sitosterol and stigmasterol were 40–50 % active, at 1 % concentration after 24 h of exposure time, while β‐sitosterol glucoside revealed no activity against the nematode.     

An Optimal Au Grating Structure for Light Absorption in Amorphous Silicon Thin Film Solar Cell

Plasmonics - Effect of different gold (Au) grating structures on light absorption in solar cell is investigated by finite elemental analysis using COMSOL multiphysics-RF module. The geometry of the...     

In-vitro GIT Tolerance of Microencapsulated Bifidobacterium bifidum ATCC 35914 Using Polysaccharide-Protein Matrix

Probiotics and Antimicrobial Proteins - Longevity of probiotic is the main concern for getting maximum benefits when added in food product. Bifidobacterium, a probiotic, tends to lose its viability...     

Substrate availability regulates the suppressive effects of Canada goldenrod invasion on soil respiration

基质有效性调节加拿大一枝黄花入侵对土壤呼吸的抑制作用 外来植物入侵不仅会降低河边近岸湿地生态系统植被多样性,而且会改变湿地生态系统的地下碳过程。外来入侵植物加拿大一枝黄花(Solidago canadensis L.)已广泛入侵我国东南部地区,但加拿大一枝黄花入侵对入侵地生态系统地下土壤碳循环过程的影响却知之甚少。本研究通过野外原位观测实验和温室模拟入侵实验,探究外来植物加拿大一枝黄花入侵对入侵地土壤呼吸的影响规律及其驱动因素。野 外原位观测实验开展于2018年7月21日至12月15日,期间每周测定样地土壤呼吸。温室模拟入侵实验开展于2019年7月15日至12月15日,期间每月1日与15日上午测定土壤呼吸、自养呼吸和异养呼吸。土壤呼吸、自养呼吸和异养呼吸通过静态箱结合深埋根系隔离法测定。野外原位观测实验和温室模拟入侵实验结果均显示,加拿大一枝黄花的入侵降低了土壤二氧化碳的排放通量。加拿大一枝黄花入侵对土壤呼吸的抑制作用可能归因于其入侵引起的土壤可利用底物质量与数量的变化,表明外来入侵植物加拿大一枝黄花可通过改变植物释放基质以及与本地植物和/或土壤微生物争夺土壤有效基质而影响土壤碳循环。这些研究结果对于评估外来入侵植物对入侵地地下碳动态的影响以及对全球变暖的贡献具有重要意义。