Electrophytochemistry - an emerging field of activity

Electrophytochemistry is an interdisciplinary area that deals with the electrical and electrochemical asDects of Dlant science. Some of the basic techniaues involved are (i) the measurement of &ll potential (transmembrane) using microelectrodes (ii) the monitoring of plant-body potential embedding noble metal electrode in conjunction with a reference electrode set in the soil and (iii) fusion of cells by electrical induction. Membrane studies are useful in knowing the transport of metabolytes. The variation of plant body potential with time (electrophytogram) can be related to the gross physiological activity. Electroculture remains fascinating though benefits on a large scale cannot be confidently predicted. lonoculture seems promising in improving plant health. Electrophytochemistry will play a vital role in the development of biotechnology such as biocatalytic hydrogen production and use of chlorophyll merrtbrane in constructing photoelectric cells. The electrically induced fusion of cells and entrapment of membrane impermeable substances and genes in them provide a new tool for the production of a wide range of cells with manipulated functions, which are used for the solution of problems in cell biology, medicine and technolog

Buffering action of hydrilla verticillata on the aquatic ph and the effect of cadmium ions on this plant

During photosynthesis on Hydrillaverticillata, the pH of the surrounding water is rendered slightly alkaline and in the absence of light the pH is brought back to near neutral condition. However, if the habitat pH IS ac~dico r alkaline due to the effluents present, this plant has a remarkable buffering capacity to bring the habitat pH to optimum, which is near-neutral. The ability of the plant to raise the pH of the habitat from 7 to slightly alkalinity under illumination is lost when cadmium ions are present in water. The buffering action of the plant has been studied in (a) acidic and alkaline conditions (b) natural and distilled water and (c) nutrient solutions under normal and artificial illumination. A typical electrophyiogram of a twig is also included

Plant bioelectric potential variation in croton (euphorbiaceous genus codiaeum) under natural light conditions pulse anodic stripping voltammetry

Plant bioelectric potential (BEPI variation was observed in actively photosynthesizing leaves of croton plant under natural light conditions. It was found to vary with the intensity of light. BEP reached a 'saturation' value in 4 to 4% hours time on upper surface of leaf, whereas 'saturation' occurred in 2 % hours for the lower surface of the leaf. The BEP of leaf exposed to sunlight was considerably higher than that of leaf covered. The BEP slowly declined after the 'saturation' value during midday and reached a minimum at midnight and early hours of the day. It is suggested here that BEP arises due to light dependent processes namely photosynthesis in plant

Influence of prolonged submergence on the electrochemical properties of karaikudi red soil of lateritic origin

Karaikudi red soil of lateritic origin was subjected to prolonged submergence under laboratory conditions. The changes in its electrical resistance, pH and soil redox potential were monitored over a period of 60 days. From the initial value of 340 mV, the E, fell to -360 mV and remained thereafter al'most steady. At a steady pH of 6.9 the most probable soil redox equilibrium that controls the E, value at this level could be the Fe+++lFeti system. The fall in pH was from 7.5 to 6.9 only, probably owing to the presence of low organic carbon content. The bulk resistance decreased from 300 to 150 ohms due to the release of ions into the soil solution. Another soil sample was kept under submergence in a glass container for a period of 41 days. The soil solution collected during this period was analysed for Na, K, Ca, Zn, Mn and Fe using AAS. The concentrations of almost all the ions increased with time. The release of iron took almost two days. The E, values have been correlated with the increasing concentration of Mn and Fe over this period. The rising concentration curves of Mn and Fe are exponential in nature

Water status of a plant body and its ohmic resistances

The electrical resistivity of a plant body was determined using (i) a four probe resistivity bridge and (ii) a two probe a.c. conductivity bridge. Measurements were taken by inserting Pt electrode either into the stem or leaf petiole. Measurements by d.c. method had been found to result in polarization. The plant body resistivity was of the order of 10^4-10^5 om.cm. The i-E curves obtained for plant leaves and stems were linear. Resistance measured varied predictably with uptake and loss of water and correlated positively with measurements of leaf water potential (LWP) and also leaf electric potential (LEP). In this paper, correlation between electrical resistance, LWP and LEP are presente

Electropotential measurements on germinating seeds of country bean (dolichos lablab)

Electropotentials (EP) of germinating country bean, Dolichos lablab remained steady initially for 3-4 days. As the radicle emerged out, the potential decreased by about 200 mV and remained at this level for 2-3 days. As seedlings turned green the potential rose gradually by 200-400 mV and remained steady. These changes in electropotentials were marked under hydroponic conditions than in a plant grown on the soil. The fall and rise in EP are distributed to respiration and photosynthesis respectivel

Recent advances in plant bioelectromagnetics

This review analyses the state-of-the-art in the field of bioelectromagnetics with respect to plant growth. The field induced had been either constant or pulsating, varying from weak to strong. This paper summarises the observations and discusses the possible mechanism

Effects of colour lights and saline water irrigation on the germination and cation uptake of capsicum annuum

The chilli seeds were germinated under different colour lights. The percentage of germination was in the order red >= yellow >= green > control > blue. Energy rations of red, yellow, green, and blue lights against control were 1.13 > 1.03 > 0.92 and > 0.76. The chlorophyll ratio against the control was in the reverse order. Under pot conditions, upto 0.33% NaCl solution enhanced seed germination compared with ordinary tap water. However, the percentage of survival decreased as the concentration of salt increase