Bioactive Compounds in Marine Macro Algae and Their Role in Pharmacological Applications
Parimelazhagan Thangaraj in Phytomedicine, 2020
Plant growth hormones are available in seaweed extracts, which are used to induce plant growth and to improve the photosynthesis. Cytokinins are plant growth regulators that protect plants from temperature variations (Tarakhovskaya et al. 2007; Zhang et al. 2010), and these are synthesized by means of the bio-chemical modification of adenine. Other plant hormones are auxin, abscisic acid, and betaines that are found in macro algal extracts. Auxin functions to start the root formation and reduce its elongation, their concentration may vary, and it depends up on the species. Gibberellins play a major role to start seed germination and are formed in developing seeds from glyceraldehydes-3-phosphate. They were first identified in two brown algal extracts, such as a Fucus vesiculosus and Fucus spiralis (Tarakhovskaya et al. 2007). Abscisic acid is formed from carotenoids by more than 60 species of algae, and betaines are not usual plant hormones, which are also found in seaweed extracts (MacKinnon et al. 2010), and their role is to guard the plants from drought and frost (Craigie 2011). The brown algal extract, Ascophyllum nodosum, has a rich source of betaines (Khan et al. 2009; Craigie 2011).
Calcium and Cytokinin in Mosses
R. N. Chopra, Satish C. Bhatla in Bryophyte Development: Physiology and Biochemistry, 2019
Initiation of cell division in plants is under the control of a class of compounds called cytokinins, N6-substituted adenines (see Reference 1 and references cited therein). I have recently postulated that these hormones may exert at least part of their effect on cells by modulating the intracellular calcium ion concentration ([Ca2+]i) in both a temporal and spatial manner within cells. Two calcium-dependent systems may be envisioned to be working in concert to effect physiological change, i.e., via calmodulin (CaM) activation and subsequent regulation of Ca/CaM-dependent protein kinases2,3 and via production of the phosphatidylinositol (PI)-derived messengers inositol trisphosphate (IP3) and diacylglycerol (DG, which activates protein kinase C).4-10 Much of the evidence for the extension of these models to plant systems has come from research on cytokinin-induced cell division and bud formation in target caulonema cells of mosses11-23 and research on cytokinin effects on calcium status of other cytokinin-responsive systems.24
Seaweed as Source of Plant Growth Promoters and Bio-Fertilizers
Gokare A. Ravishankar, Ranga Rao Ambati in Handbook of Algal Technologies and Phytochemicals, 2019
Seaweed extract is one of the sources of phytohormone cytokinin. Cytokinins have been detected in fresh seaweeds (Hussein and Boney, 1969) as well as seaweed extracts (Brain et al., 1973). Various available forms of cytokinins are present in seaweed extracts include trans-zeatin, trans-zeatin riboside and dihydro derivatives of these two forms (Stirk and van Staden, 1997). Seawater taken from the Fucus-Ascophyllum zone is found to contain cytokinin in the form of zeatin (6-3-methyl-2-butenylamino purine). Different forms of cytokinins like iso-pentenyl adenosine, zeatin, zeatin riboside, dihydrozeatin, iso-pentenyladenine, 2-hydroxy-6-methylaminopurine and 2-hydroxy-1-methylzeatin have been isolated from Sargassum muticum, Porphyra perforata and Chara globularis of seaweeds. Mostly crop responses to different seaweed extracts are thought to be primarily due to the response of plant hormone cytokinin. Seaweed extracts with cytokinin activity are capable of producing physiological change, even when applied at low concentrations used under field conditions. Several cytokinins like trans-zeatin, trans-zeatin riboside and their dihydroderivatives; iso-pentenyladenine; iso-pentenyl adenosine and several cytokinin glucosides have been identified and quantified in several seaweed extracts (Panda et al., 2012).
Evaluation of the optimum threshold of gamma-ray for inducing mutation on Polianthes tuberosa cv. double and analysis of genetic variation with RAPD marker
Published in International Journal of Radiation Biology, 2023
Hanifeh Seyed Hajizadeh, Seyed Najmedin Mortazavi, Morteza Ganjinajad, Volkan Okatan, İbrahim Kahramanoğlu
Increasing the radiation dose did not significantly increase this trait in general, so the treatments of 20, 30, and 40 Gy doses of γ-ray did not significantly differ from the control, and only the treatment of 50 Gy showed a significant difference compared to the control and other lower levels of radiation (Table 3). Ling et al. (2008) reported that plants grew more at 10 Gy, while doses above 10 Gy inhibited plant growth, indicating that increased radiation increases the plant’s tolerance to γ-radiation. It may be explained by a decrease in the amount of endogenous plant hormones, especially cytokinin, which results in cytokinin degradation or lack of biosynthesis due to irradiation. It is clear that damage to the cells of tuberose was so serious at the gamma-ray dose of 50 Gy.
A novel and effective technique to reduce electromagnetic radiation absorption on biotic components at 2.45 GHz
Published in Electromagnetic Biology and Medicine, 2022
Meenu L, Aiswarya S, Sreedevi K. Menon
This experiment is a direct validation and serves as a proof of concept that the EMR exposure rate, time and intensity has an adverse effect on the plant tissues. The study shows that the variation in secretion of plant hormones like Gibberellins, Cytokinins, Abscisic Acid and Auxins had led to the retardation in the complete growth of the plant (Naqvi 1999) – (Arteca 1996.). The radiation is mainly due to the antenna present in the gadgets and these radiations will be absorbed by the vegetation. This is measured in terms of SAR for a given tissue. SAR depends upon dielectric property, conductivity, mass density, electric field strength of the tissues etc. The absorption of radiation by pea seeds near to the router is more as it receives more power in the vicinity of the router. So the variation in absorption results in growth retardation even from its initial stage of the germination. This effect in the sprouting stage makes changes in the entire life cycle of each plant community. These continuous exposure reduces the nutrient capability of vegetations and it makes them unhealthy to human life.
Potential antioxidant and anti-inflammatory action of Hypericum hookerianum extracts in a liposome system evaluated with zebrafish embryos
Published in Journal of Microencapsulation, 2019
P. S. Pradeep, S. Manisha, J. Monica Amala Nayaki, D. Sivaraman, R. Selvaraj, S. Seeni
Seeds (Figure 1(A)) began to germinate within 8 d after inoculation on MS media. The seed germination rate was found to be 83% and began to develop protocorms (Figure 1(B)). Thereafter, protocorms undergo further differentiation to produce one cotyledon (Figure 1(C)). These cotyledon segments when cultured on MS media supplemented with 1.0 mgl−1 KN concentrations resulted in longitudinal growth all devoid of any morphological outgrowths or pigment synthesis (Figure 1(D)). On the other hand, the cotyledon explants cultured on 0.1 mgl−1 NAA showed marginal callusing with no extended growth but remarkable changes occurred with the phenomenal synthesis of red pigmentation (Figure 1(E)). The red pigments visibly in incremental proportions within 2 weeks gradually increased in concentration reaching saturation in eight weeks. It appears that the pigment synthesis is auxin-induced and the presence of cytokinin did not alter the red pigment synthetic pathway.
Related Knowledge Centers
- Auxin
- Datura
- Ground Tissue
- Nicotiana Tabacum
- Xylem
- Plant Hormone
- Apical Dominance
- Plant Senescence
- Zeatin
- 6-Benzylaminopurine