scholarly journals The role of JrPPOs in the browning of walnut explants

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Shugang Zhao ◽  
Hongxia Wang ◽  
Kai Liu ◽  
Linqing Li ◽  
Jinbing Yang ◽  
...  
Keyword(s):  
Tissue Culture ◽  
Production Efficiency ◽  
Phenolic Content ◽  
Leaf Tissue ◽  
Limiting Factor ◽  
Mature Leaves ◽  
Survival Percentage ◽  
Highly Active ◽  
Young Leaves

Abstract Background Tissue culture is an effective method for the rapid breeding of seedlings and improving production efficiency, but explant browning is a key limiting factor of walnut tissue culture. Specifically, the polymerization of PPO-derived quinones that cause explant browning of walnut is not well understood. This study investigated explants of ‘Zanmei’ walnut shoot apices cultured in agar (A) or vermiculite (V) media, and the survival percentage, changes in phenolic content, POD and PPO activity, and JrPPO expression in explants were studied to determine the role of PPO in the browning of walnut explants. Results The results showed that the V media greatly reduced the death rate of explants, and 89.9 and 38.7% of the explants cultured in V media and A media survived, respectively. Compared with that of explants at 0 h, the PPO of explants cultured in A was highly active throughout the culture, but activity in those cultured in V remained low. The phenolic level of explants cultured in A increased significantly at 72 h but subsequently declined, and the content in the explants cultured in V increased to a high level only at 144 h. The POD in explants cultured in V showed high activity that did not cause browning. Gene expression assays showed that the expression of JrPPO1 was downregulated in explants cultured in both A and V. However, the expression of JrPPO2 was upregulated in explants cultured in A throughout the culture and upregulated in V at 144 h. JrPPO expression analyses in different tissues showed that JrPPO1 was highly expressed in stems, young leaves, mature leaves, catkins, pistils, and hulls, and JrPPO2 was highly expressed in mature leaves and pistils. Moreover, browning assays showed that both explants in A and leaf tissue exhibited high JrPPO2 activity. Conclusion The rapid increase in phenolic content caused the browning and death of explants. V media delayed the rapid accumulation of phenolic compounds in walnut explants in the short term, which significantly decreased explants mortality. The results suggest that JrPPO2 plays a key role in the oxidation of phenols in explants after branch injury.

scholarly journals Isotopic signatures reveal zinc cycling in the natural habitat of hyperaccumulator Dichapetalum gelonioides subspecies from Malaysian Borneo

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Antony van der Ent ◽  
Philip Nti Nkrumah ◽  
Mark G. M. Aarts ◽  
Alan J. M. Baker ◽  
Fien Degryse ◽  
...  
Keyword(s):  
Leaf Litter ◽  
Natural Habitat ◽  
Parent Rock ◽  
Deep Soil ◽  
Isotopic Signatures ◽  
Mature Leaves ◽  
Young Leaves ◽  
Malaysian Borneo ◽  
Zn Isotopes

Abstract Background Some subspecies of Dichapetalum gelonioides are the only tropical woody zinc (Zn)-hyperaccumulator plants described so far and the first Zn hyperaccumulators identified to occur exclusively on non-Zn enriched 'normal' soils. The aim of this study was to investigate Zn cycling in the parent rock-soil-plant interface in the native habitats of hyperaccumulating Dichapetalum gelonioides subspecies (subsp. pilosum and subsp. sumatranum). We measured the Zn isotope ratios (δ66Zn) of Dichapetalum plant material, and associated soil and parent rock materials collected from Sabah (Malaysian Borneo). Results We found enrichment in heavy Zn isotopes in the topsoil (δ66Zn 0.13 ‰) relative to deep soil (δ66Zn -0.15 ‰) and bedrock (δ66Zn -0.90 ‰). This finding suggests that both weathering and organic matter influenced the Zn isotope pattern in the soil-plant system, with leaf litter cycling contributing significantly to enriched heavier Zn in topsoil. Within the plant, the roots were enriched in heavy Zn isotopes (δ66Zn ~ 0.60 ‰) compared to mature leaves (δ66Zn ~ 0.30 ‰), which suggests highly expressed membrane transporters in these Dichapetalum subspecies preferentially transporting lighter Zn isotopes during root-to-shoot translocation. The shoots, mature leaves and phloem tissues were enriched in heavy Zn isotopes (δ66Zn 0.34–0.70 ‰) relative to young leaves (δ66Zn 0.25 ‰). Thisindicates that phloem sources are enriched in heavy Zn isotopes relative to phloem sinks, likely because of apoplastic retention and compartmentalization in the Dichapetalum subspecies. Conclusions The findings of this study reveal Zn cycling in the rock-soil-plant continuum within the natural habitat of Zn hyperaccumulating subspecies of Dichapetalum gelonioides from Malaysian Borneo. This study broadens our understanding of the role of a tropical woody Zn hyperaccumulator plant in local Zn cycling, and highlights the important role of leaf litter recycling in the topsoil Zn budget. Within the plant, phloem plays key role in Zn accumulation and redistribution during growth and development. This study provides an improved understanding of the fate and behaviour of Zn in hyperaccumulator soil-plant systems, and these insights may be applied in the biofortification of crops with Zn.

scholarly journals Further Studies on the Role of Leaves in Sugarcane Flowering

1969 ◽  
Vol 58 (4) ◽  
pp. 393-405
Author(s):  
Teh-ling Chu ◽  
J. L. Serapión
Keyword(s):  
Flowering Time ◽  
Flowering Response ◽  
Sugarcane Varieties ◽  
Floral Stimulus ◽  
Mature Leaves ◽  
Defoliation Treatment ◽  
Young Leaves ◽  
Flowering Intensity

The role played by leaves in the perception and inhibition of the flowering stimulus was studied through defoliation treatment in three sugarcane varieties. It was found that the expanding leaves (0 and —1) in the variety P.R. 980 appear to be most effective in producing a flowering stimulus. The mature leaves (+3 and +4) in the variety Cl 41-223 appear to produce a transmissible flowering inhibitor. Absence of the young leaves within the leaf spindle during a period critical to initiation of inflorescence primordia resulted in a significant reduction of flowering intensity in varieties N.Co. 310 and Cl 41-223, and a marked delay in the flowering time in N.Co. 310. Removal of these leaves during subsequent stages of inflorescence caused a somewhat depressive flowering response and a considerable delay in the flowering time of N.Co. 310. A late-initiating variety, Cl 41-223 appears to begin producing a floral stimulus around August 20, about 2 to 3 weeks later than that of the early-initiating variety N.Co. 310.

Sorbitol Versus Sucrose as Photosynthesis and Translocation Products in Developing Apricot Leaves

1985 ◽  
Vol 12 (6) ◽  
pp. 657 ◽  
Author(s):  
RL Bieleski ◽  
RJ Redgwell
Keyword(s):  
Leaf Development ◽  
Main Product ◽  
Mature Leaf ◽  
Young Leaf ◽  
Mature Leaves ◽  
Specific Transport ◽  
Young Leaves

Very young apricot leaves behave like the young leaves of most plants; that is, [14C]sucrose is formed as the main product of 14CO2 photosynthesis, and also when the leaves are supplied with [14C]glucose. [14C]sorbitol is not produced, and is poorly metabolized when fed to the leaf. Expanding leaves behave differently: [14C]sorbitol and [14C]sucrose are formed in similar amounts from both 14CO2 and [14C]glucose; and when [14C]sorbitol is supplied, it is readily metabolized and utilized for growth. Mature leaves are different again. They form [14C]sorbitol as the main product from 14CO2 and from [14C]glucose, and they do not metabolize [14C]sorbitol at all. Thus during development, apricot leaves gain but then lose the ability to utilize sorbitol. They also gain and keep the ability to synthesize sorbitol. This suggests that different biochemical paths exist for sorbitol formation and utilization, and that these paths are differently developed in the various stages of leaf development. Although the very young leaves did not synthesize sorbitol from CO2 or glucose, they contained it as their major sugar. Translocation behaviour was therefore studied. Neither the very young leaves nor the expanding leaves export any photosynthate, but the mature leaf rapidly translocates carbohydrate, mainly in the form of sorbitol, to the younger leaves as well as the rest of the plant. [14C]sorbitol supplied to the mature leaf can be recovered in that form from the very young leaf on the same shoot. This further establishes the role of sorbitol in apricot as a specific transport carbohydrate.

Role of Histidine and Tyrosine Decarboxylases and Mono- and Diamine Oxidases in Amine Build-Up in Cheese

1978 ◽  
Vol 41 (3) ◽  
pp. 182-186 ◽  
Author(s):  
M. N. VOIGT ◽  
R. R. EITENMILLER
Keyword(s):  
Free Amino ◽  
Histidine Decarboxylase ◽  
Past Research ◽  
Biologically Active ◽  
Limiting Factor ◽  
Decarboxylase Activity ◽  
Amine Oxidases ◽  
Highly Active ◽  
Mao Activity

Presence of biologically active amines in foods has been recognized for about 20 years. Past research on amines such as tyramine and histamine has not investigated factors which account for the variable concentrations often found in food products. This research was designed to investigate the roles of tyrosine and histidine decarboxylase activities and mono- and diamine oxidases (MAO and DAO) in amine formation and catabolism in cheese. The data indicate that the presence of decarboxylases is probably not the limiting factor for amine build-up. Most cheeses contained decarboxylase activities for both tyrosine and histidine; however, tyramine and histamine were present in some cheeses which did not contain detectable levels of the corresponding decarboxylases at the time of sampling. Few cheeses possessed MAO or DAO activities. When the oxidases were present, the amine contents were usually lower. A Colby cheese containing tyramine and histamine with high MAO activity also possessed high tyrosine decarboxylase activity. It appears that a major limiting factor in formation of biologically active amines in cheese is the availability of free amino acids for decarboxylation. Dairy-related bacteria generally lacked the amine oxidases. However, five of six dairy-related cultures with highly active decarboxylases showed MAO or DAO activities. The culture showing the highest DAO activity, Microbacterium lacticum, possessed low tyrosine and histidine decarboxylase activities.

Review on Ethnobotany and Phytopharmacology on Mesua ferrea Linn

2021 ◽  
pp. 195-199
Author(s):  
Sruthikrishna P.K.
Keyword(s):  
Health Issues ◽  
Phytochemical Screening ◽  
Asian Countries ◽  
Mature Leaves ◽  
Young Leaves ◽  
Tropical Areas ◽  
Anti Oxidant ◽  
Dark Green ◽  
Almost All

This work was performed to study the ethnobotany and phytopharmacological properties of M. ferrea L. It is widely distributed in the tropical areas of the world, especially in the Asian countries and is traditionally used by the local peoples for curing diseases ranging from head ache to cancer. Mesua ferrea is cultivated as an ornamental plant and young leaves are reddish yellow in color while mature leaves are blue grey to dark green in appearance with fragrant white flowers. This study reveals that almost all part of the plant have high medicinal property against different ailments. M. ferrea Linn being used for its anticancer, antineoplastic, disinfectant, anti oxidant, hepato-protective, anti arthritic, diuretic, analgesic etc. properties. The phytochemical screening confirms the presence of phenyl coumarins, xanthones, triterpenoids, tannin and saponin as main constituents responsible for its biological activity. It is also used in the cosmetics. This can be used as remedial agents for various health issues. This review reveals the phyto-pharmacological role of this medicinal plant.

RAPID IN VITRO PROPAGATION OF WESTERN GHATS CULTIVAR - COLOCASIA ESCULENTA FOR THE HIGH FREQUENCY OF PLANTLETS

2019 ◽  
Vol 7 (2) ◽  
Author(s):  
Jyothi R ◽  
Srinivasa Murthy K M ◽  
Hossein . ◽  
Veena .
Keyword(s):  
Tissue Culture ◽  
Wide Distribution ◽  
Colocasia Esculenta ◽  
Limiting Factor ◽  
Promising Alternative ◽  
Rapid Multiplication ◽  
Medical Plant ◽  
Total Fat ◽  
Planting Materials

Colocasia esculenta is commonly known as Taro, it is referred to as cocoyam in Nigeria. They are cherished for their rich taste, nutritional and medicinal properties. Every 100 g of taro corms possess 112 Kcal, 26.46 g carbohydrate, 1.50 g protein, 0.20 g total fat and 4.1g fiber (USDA National Nutrient Data Base). Besides its nutritional value, taro is used as a medical plant and provides bioactive compounds used as an anti-cancer drugs. Traditionally, cocoyams are vegetative propagated from tuber fragments, a practice that encourages pathogen distribution. Colocasia esculenta is a widely distributed food crop in the humid tropics and subtropics. Despite of its wide distribution, Taro plants are commonly infected with DsMV and other pathogens. This virus induces conspicuous mosaic, malformation, dwarfing or feathering on leaves in taro. As the results of infection, it reduces the quality and yield of taro production greatly. This virus is thus considered as a major limiting factor in the production of taro. Here plays the importance of  tissue culture plays a major role in producing the disease resistant plants round the year with high quality. For rapid multiplication and production of quality planting materials, tissue culture technology offers promising alternative compared to the traditional production methods. KEYWORDS: Colocasia esculenta, Virus, Pathogens, Conventional propagation, Micropropagation, Yield, Rapid multiplication, Quality

Testing ecological release as a compensating mechanism for mass mortality in a keystone predator

2020 ◽  
Vol 637 ◽  
pp. 59-69 ◽  
Author(s):  
J Sullivan-Stack ◽  
BA Menge
Keyword(s):  
Community Dynamics ◽  
Limiting Factor ◽  
Sea Star ◽  
Top Predator ◽  
Oregon Coast ◽  
Ecological Release ◽  
Keystone Predator ◽  
Pisaster Ochraceus ◽  
Wasting Syndrome

Top predator decline has been ubiquitous across systems over the past decades and centuries, and predicting changes in resultant community dynamics is a major challenge for ecologists and managers. Ecological release predicts that loss of a limiting factor, such as a dominant competitor or predator, can release a species from control, thus allowing increases in its size, density, and/or distribution. The 2014 sea star wasting syndrome (SSWS) outbreak decimated populations of the keystone predator Pisaster ochraceus along the Oregon coast, USA. This event provided an opportunity to test the predictions of ecological release across a broad spatial scale and determine the role of competitive dynamics in top predator recovery. We hypothesized that after P. ochraceus loss, populations of the subordinate sea star Leptasterias sp. would grow larger, more abundant, and move downshore. We based these predictions on prior research in Washington State showing that Leptasterias sp. competed with P. ochraceus for food. Further, we predicted that ecological release of Leptasterias sp. could provide a bottleneck to P. ochraceus recovery. Using field surveys, we found no clear change in density or distribution in Leptasterias sp. populations post-SSWS, and decreases in body size. In a field experiment, we found no evidence of competition between similar-sized Leptasterias sp. and P. ochraceus. Thus, the mechanisms underlying our predictions were not in effect along the Oregon coast, which we attribute to differences in habitat overlap and food availability between the 2 regions. Our results suggest that response to the loss of a dominant competitor can be unpredictable even when based in theory and previous research.

Karakter Morfologi Daun Ubi Jalar Sebagai Bahan Pangan Suku Dani Distrik Kurulu Jayawijaya

Agrotek ◽  
2018 ◽  
Vol 2 (3) ◽  
Author(s):  
Antonius Suparno ◽  
Opalina Logo ◽  
Dwiana Wasgito Purnomo
Keyword(s):  
Sweet Potato ◽  
Leaf Morphology ◽  
Food Source ◽  
Staple Food ◽  
Sweet Potatoes ◽  
General Outline ◽  
Leaf Vein ◽  
Mature Leaves ◽  
Young Leaves ◽  
Tuber Roots

Sweet potato serves as a staple food for people in Jayawijaya. Many cultivars of sweet potatoes have been cultivated by Dani tribe in Kurulu as foot for their infant, child and adult as well as feeding especially for pigs. Base on the used of sweet potatoes as food source for infant and child, this study explored 10 different cultivars. As for the leaf morphology, it was indentified that the mature leaves have size around 15 � 18 cm. general outline of the leaf is reniform (40%), 60% have green colour leaf, 50% without leaf lobe, 60% of leaf lobes number is one, 70% of shape of central leaf lobe is toothed. Abazial leaf vein pigmentation have purple (40%), and petiole pigmentation is purple with green near leaf (60%), besides its tuber roots, sweet potatoes are also harvested for its shoots and green young leaves for vegetables.

Microbial Biofilms and Biotechnology – Some Perceptions

2020 ◽  
Vol 09 ◽  
Author(s):  
Subba Rao Toleti
Keyword(s):  
Tissue Culture ◽  
Synthetic Biology ◽  
Industrial Effluents ◽  
Aquatic Environments ◽  
Biochemical Processes ◽  
Microbial Biofilms ◽  
Biofilm Bacteria ◽  
Prophylactic Vaccines ◽  
Design Construction

: The review is an attempt to introduce the readers in brief about biofilms and their implications as well as some new perceptions in biotechnology. Biofilms are adherent microbial communities, which are developed on submerged surfaces in aquatic environments. Biofilms play a significant role in exopolymer production, material deterioration and also cause harmful infections. Further, the role of corrosion causing biofilm bacteria in deterioration of different materials, microbial biofilms and their enzymatic processes in reducing the toxicity of pollutants in industrial effluents are elaborated, along with clean technologies for wastewater treatment. Biotechnology is defined as any technological application that uses biological systems to synthesize or modify products or processes. The applications include biochemical processes, medical care, cell and tissue culture as well as synthetic biology and others. Synthetic biology details about the design, construction of new biological components and systems for useful purposes. Finally, to overcome the limitations that are inherent to the use of cellular host’s, cell-free systems as critical platforms for synthetic biology applications. This mini-review also mentions about new diagnostic products based on enzymes, monoclonal antibodies and engineered proteins as well as novel prophylactic vaccines.

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