Comparative genomics of Mycobacterium reveals evolutionary trends of M. avium complex

Mycobacterium is gram positive, slow growing, disease causing Actinobacteria. Beside potential pathogenic species, Mycobacterium also contains opportunistic pathogens as well as free living non-pathogenic species. Disease related various analyses on Mycobacterium tuberculosis are very widespread. However, genomic study of overall Mycobacterium species for understanding the selection pressure on genes as well as evolution of the organism is still illusive. MLSA and 16s rDNA based analysis has been generated for 241 Mycobacterium strains and a detailed analysis of codon and amino acid usage bias of mycobacterial genes, their functional analysis have been done. Further the evolutionary features of M. avium complex also have been revealed. Mycobacterial genes are moderately GC rich showed higher expression level in PPs and significant negative correlation with biosynthetic cost of proteins. Translational selection pressure was observed in mycobacterial genes. MAC showed close relationship with NPs and higher evolutionary rate in MAC revealed their constant evolving nature.     

Polybenzyls from Gastrodia elata,their agonistic effects on melatonin receptors and structure-activity relationships

Gastrodia elata is a famous traditional Chinese herb with medicinal and edible application. In this study, nine polybenzyls (1?9), including six new ones (2?5, 7 and 9), were isolated from the EtOAc extract of G. elata. Five compounds 1, 3, 4, 6 and 8 were found to activate melatonin receptors. Especially, compound 1 showed agonistic effects on MT₁ and MT₂ receptors with EC₅₀ values of 237 and 244 μM. For better understanding their structure-activity relationships (SARs), ten polybenzyl analogs were further synthesized and assayed for their activities on melatonin receptors. Preliminary SARs study suggested that two para-hydroxy groups were the key pharmacophore for maintaining activity. Molecular docking simulations verified that compound 1 could strongly interact with MT₂ receptor by bonding to Phe 118, Gly 121, His 208, Try 294 and Ala 297 residues.     

Differentiation of chloroplast lamellae: Light harvesting efficiency and grana development

Incomplete development of chloroplast lamellae occurred when etiolated pea plants were greened under cycles of 2 min light, 118 min dark. Although the plastids had full photochemical activities, they were nearly agranal. They were also characterized by a high quantum requirement for whole chain electron transport in low light; this is thought to be the result of unequal light absorption by incompletely developed light-harvesting assemblies of photosystem I and II and a lack of regulation of excitation energy distribution between the two photosystems. Continuous illumination induced the final stages of membrane differentiation. These stages were primarily characterized by the appearance of grana stacking and an increase in photosynthetic unit size. A biphasic decrease in quantum requirement for whole chain electron transport correlated directly with the appearance of grana during the final steps of membrane assembly. Structural organization of the membrane may be related to the light-harvesting efficiency of the membrane.     

Honeybush (Cyclopia spp.): From local cottage industry to global markets — The catalytic and supporting role of research

Honeybush tea (Cyclopia spp.), one of the traditional South African herbal teas with a long history of regional use, remained a cottage industry until the mid-1990s when researchers were instrumental in the development of a formal agricultural and agro-processing industry. It is one of the few indigenous South African plants that made the transition from the wild to a commercial product during the past 100 years. Research activities during the past 20 years included propagation, production, genetic improvement, processing, composition and the potential for value-adding. The present review provides an up-to-date and comprehensive record of the development of the South African honeybush industry, against the background of the historical highlights in the making of an industry. It provides a blueprint of the processes and actions involved in the development of a new agricultural and agro-processing industry from an herbal plant. Insight into challenges faced by the industry and future research needed to keep it competitive are provided.     

Comparative study on floristic diversity of protected and unprotected Forests of Sathan Gali,District Mansehra,KP, Pakistan

This first ever study was carried out to explore the floristic composition of protected and unprotected forests of Sathan Gali, District Mansehra, KP, Pakistan. The study area being the part of the Western Himalayas harbours rich floristic diversity. In the current investigation, an effort was made to record primary data about floral diversity of the area. The study area was visited recurrently during 2013 and 2014. Plants were collected from different sampling sites, identified, preserved and deposited in Herbarium of Hazara University, Mansehra. A total of 127 plants species including 59 common and 68 different were found in 13 stands of reserved forest. The different species were only confined with this forest whereas common plant species were distributed in both forests. The dominant family was Asteraceae (13 species, 10.7%) followed by Labiateae (10 species, 7.75%), Poaceae and Rosaceae (8 species, 6.2%) each, Polygonaceae and Pteridaceae by (5 species, 3.87%) each. Angiosperms were represented by 118 (92.91%), plant species, Pteridophytes 5(3.93%) species and Gymnosperms 4 (3.14%) species were recorded in reserved forest. Only single species of climber was documented. The number of herbs, shrubs and trees species recorded were 73.64%, 13.17% and 10.07% respectively. A total of 103 plant species of 55 families including 61 common in both forest types and 42 species different to guzara Forest. These plant species were recorded from 22 sampling stands. Angiosperms by (92.3%) plant species, Gymnosperms (2.88%) and Pteridophytes (4.8%) were recorded. The dominant family was Poaceae by 11 plant species followed by Asteraceae and Rosaceae each represented by 10 species and Pteridaceae by 5 plant species. Habit wise 69.23% were herbs, 14.42% shrubs and 16.34% species of tree were reported. This study will assist ecologists, botanists, taxonomist, conservationists and policy makers to mend, and manage the current vegetation status and sustainability for upcoming generations. The present investigation will also serves as base line for future researches on the Himalaya regions.     

植物学课程体系的改革与实践

介绍了以能力培养为主线、分层次、理论与实践教学既有机衔接又相对独立的植物学课程新体系,重点介绍了"3 1"模式的植物学实验课程体系(基本型、综合型、研究探索型三个层次实验课程和野外实习训练),并由此进行了植物学实验课程内容体系、教学模式、教学方法、开放运行模式等方面深层次的改革,形成了一定的特色和优势。新体系付诸了实践和推广,取得良好的效果。     

The rise in chlorophyll a fluorescence yield and decay in delayed light emission in Tris-washed chloroplasts in the 6–100 μs time range after an excitation flash

Parallel measurements of the rise in chlorophyll a fluorescence yield and delayed light emission decay, after a 10 ns saturating excitation flash, have been made in tris(hydroxymethyl)aminomethane-washed chloroplasts. Various electron donor systems (Mn²⁺; ascorbate; reduced phenylenediamine and benzidine) were used in conjuction with different preillumination regimes to alter [P⁺-680], the oxidized form of the Photosystem II reaction center chlorophyll a. Conditions giving rise to high [P⁺-680] resulted in only a small rise in fluorescence yield, an inhibition of a 6 μs delayed light component, and an enhancement of a 60 μs component of delayed light emission. These results confirm the hypothesis that P⁺-680 acts as a quencher of fluorescence and that delayed light emission in the microsecond time range is due to the back reaction of P⁺-680 and Q^?. (Q is the first “stable” electron acceptor of Photosystem II.) Two preillumination flashes are required before the full effect of Tris washing is observed in the delayed light emission decay and fluorescence yield rise; this suggests that a capacity to hold two charges exists between the Tris block and P⁺-680. Tris washing has no direct effect on the movement of electrons from Z (the first electron donor to P⁺-680) to P⁺-680. Finally, Mn²⁺ donates electrons to P⁺-680 via Z.