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Hardseededness is attributed by impermeable seed coats which mechanically restricts embryo growth and delays germination even under suitable conditions. The presence of larger proportion of hard seeds delays germination and can reduce crop yield due to uneven growth and stand establishment. The information regarding the seed surface characteristics in regulating the hardseededness in green gram is still insufficient. This study addressed the knowledge gap by examining the seasonal impact on development of hard seed and seed surface characteristics in green gram. In predominantly hardseeded (HS) genotypes, there was a decrease in hard seeds during the summer season compared to Kharifseason. Scanning electron microscope analysis revealed that HS genotypes had smoother surfaces, closely packed hilum cells, and closed strophioles, while non-hardseeded (NHS) genotypes had rougher surfaces, opened strophioles, and loosely packed hilum cells. Seeds from HS genotypes in the summer season had characteristics of non-hard seeds like opened strophioles and loosely packed hilum cells, making them permeable to water. Scanning electron microscope features effectively differentiated between HS and NHS genotypes and seeds produced in different seasons. This information may be used for identification of genotypes and seed lots with desirable hard seed percentage through high-throughput image analysis.

The current trend of continuous release of rice varieties has made it necessary to develop adequate methodologies for varietal identification at the laboratory level, especially when seeds are submitted for purity analysis. Grow Out Test is time-consuming and is are, therefore, of limited practical utility. Seed coat react with added phenol and change in its colour is useful for variety classification. These assessments are quick, easy to perform, reproducible and environment-independent. Rice grains respond to phenol solution and its colour is changed differently among varieties. However, no standard method is available in phenol colour reaction test like wheat. Therefore, experiments were conducted to standardize phenol concentration, quantity, Petri plate size and duration of reaction to obtain a stable colour development in varieties of different phenol colour group rice variety. In this study five ml of two percentage phenol solution with in 11 cm diameter or with 4 ml in nine cm Petri plate, incubated for four hours at 25 °C has been found to produce a stable seed coat colour. The results of these tests are typically distinct, easy to understand, and aid in genotype grouping.

The A2Πg← X2Πuelectronic transition (4800–6000 Å) of triacetylene cation was measured in an ion trap, where the vibrational and rotational degrees of freedom were equilibrated to 25 K. The rotational profile of the origin band is predicted by a collisional-radiative rate model under conditions expected in diffuse interstellar clouds. Variation in the density of the surrounding gas, rotational temperature, and velocity dispersion are taken into account.

ABSTRACTThis paper presents the design of a common aperture dual-band microstrip antenna at 1.25 and 2.5 GHz. The antenna is dual-linear polarized at both the frequencies. The single antenna element configuration is probe-fed square annular patch at L-band and electromagnetically coupled stacked patch at S-band. L- and S-band patches are on separate layers and share the same aperture. A planar antenna has been designed using 2 × 6 elements array at L-band and 4 × 12 elements array at S-band. The antenna size is 0.36 m × 1.1 m. The measured peak gain is 16.9 dBi at 1.25 GHz and 20.7 dBi at 2.5 GHz. The cross-polarization and port to port isolations are better than 30 dB at both the frequencies.

Abstract: In this paper, sliding mode control for discrete time systems with stochastic noise in their input channel has been discussed. The idea of process control using control charts has influenced this new approach towards dealing with systems with stochastic noise. The new approach approximates the stochastic noise as a bounded uncertainty, similar to having bounds in the control charts for stochastic process control data. For discrete time systems, this results in a bounded stability in probability of the quasi sliding mode, which is referred to as the N-sigma bounded stability. The probability associated with the stability notions is not fixed and the control engineer may desire lower or higher degrees of stability in terms of this probability. Thus one has design flexibility while implementing the theory in practice, where one might have to adjust the desired degree of stability due to hardware limitations. [Copyright &y& Elsevier]

Tumor cell tissue factor (TF)‐initiated coagulation supports hematogenous metastasis by fibrin formation, platelet activation and monocyte/macrophage recruitment. Recent studies identified host anticoagulant mechanisms as a major impediment to successful hematogenous tumor cell metastasis.

Thirty-four diverse accessions of Jatropha curcasL. were studied for physiological parameters viz.,net photosynthesis (Pn), stomatal conductance (gs), transpiration rate (E) and leaf temperature difference (?T) and exhibited significant variation under semi-arid field conditions. The mean net photosynthesis (Pn) was 15 µmol m-2 s-1and maximum net photosynthesis was recorded by IC537862 (24 µmol m-2 s-1). Accession, IC544693 recorded highest stomatal conductance and transpiration rate of 0.77 and 8.81 mmol m-2s-1respectively, whereas accession IC537877 showed lowest value of 0 for both of these traits. Correlation studies showed linear positive relationship between Pn and gs(r= 0.72) and Pn and E (0.77). Based on the physiological traits, accessions suitable for moisture limiting conditions viz.,IC471314, IC541660 and irrigated conditions viz.,IC537862, IC537914, IC565044, IC565048 were identified. Multivariate cluster analysis helped in identification of physiologically diverse accessions viz.,IC565048, IC550849, IC537869 and IC 544654 which were suitable for incorporation in breeding programmes.

AbstractThis paper presents the design and the experimental results of a dual-mode rectangular-matched feed. This type of feed cancels the unwanted high cross-polarization generated by the offset parabolic reflector antenna. In order to design this feed, higher order TE11mode has been added in correct amplitude and phase with the fundamental TE01mode in a rectangular structure. The proposed feed was then used as a primary feed to illuminate a linearly polarized offset parabolic reflector antenna. Through experimental results, it is verified that such a feed suppresses the undesired high cross-polarization introduced by the offset geometry of an offset reflector antenna. This kind of feed is very much suitable for monopulse tracking radar.

Sirtuin (Sir2) proteins being key regulators of numerous cellular processes have been, over the recent past, the subject of intense study. Sirs have been implicated in diverse physiological processes ranging from aging and cancer to neurological dysfunctions. Studies on Sir2s using tools of genetics, molecular biology, biochemistry and structural biology have provided significant insight into the diverse functions of this class of deacetylases. This apart, medicinal chemistry approaches have enabled the discovery of modulators (both activators and inhibitors) of Sir2 activity of diverse chemical structures and properties. The availability of these small molecule modulators of Sir2 activity not only has pharmacological significance but also opens up the possibility of exploiting chemical genetic approaches in understanding the role of this multi-functional enzyme in cellular processes.

The article reports on the need for policies covering the textile engineering industry (TEI) in India. It is noted that the sector has been producing machinery from borrowed technology under foreign collaborations or imported drawings and designs. Categories of machinery include spinning and allied machines, processing machines and textile testing and measuring instruments.

The article discusses the results of a survey on the production of textile machinery in India. Machinery production had been increasing from 2004 to 2008 until the country experienced sluggishness between 2008 and 2009 due to the global recession. India has the capability of manufacturing parts and accessories of a spinning machinery including the ring frame, the speed frame, and the combers. The country also has the capability of manufacturing parts and accessories of a weaving preparatory machinery which include the jacquard, the drop wire, and the heald wire.

This paper presents the design of a dual frequency microstrip patch antenna. The design is presented at C and X band with centre frequency at 5.35 and 9.6 GHz respectively. The radiating element at C band is a microstrip patch while the radiating element at X band is a slot. Simulated and measured data are presented as a function of geometrical parameters.

This paper presents the design and development of a wideband dual polarised linear array antenna of 4 elements in C-band, the centre frequency is 5.3 GHz. The radiating element is of stacked SSFIP configuration. The complex excitation coefficients of the antenna has been chosen in order to achieve a fixed beam-pointing by 10° and side-lobe level better than -15 dB. The array antennna offers bandwidth of 22% for a VSWR ratio of 2:1. The measured S-parameters and radiation pattern are presented.

Excitation functions for evaporation residues of the system 16O + 165Ho have been measured up to 100 MeV. Recoil range distribution of long lived reaction products were measured at 16O beam energy of 100 MeV. Detailed Monte Carlo simulation of recoil range distributions of products were performed with the help of PACE2 code, in order to extract the contributions of incomplete fusion in the individual channels. The results clearly show the incomplete fusion contributions in the tantalum and thulium products. This is confirmed by the predictions of breakup fusion model of the incomplete fusion.

A solar pond technology employs a layer of salinity gradient to prevent heat loss due to convection from the lower convective zone. Thus, the energy received from solar radiation is stored in a lower convective zone. The thickness of various zones significantly affects the behaviour of solar pond temperature. In this present study, a transient numerical investigation is conducted to evaluate the impact of depths of different zones on the performance characteristics of solar pond. The variation in maximum temperature and maturation period under the influence of non-convective zone and lower convective zone thickness is discussed. The energy obtained from a solar pond significantly depends on various losses associated with the zones. Thus, an assessment of conduction and ground heat loss is presented for the variation in thickness of zones. An attempt is also made to study the effect of thickness of zones on the temperature of the lower convective zone. It is found that the configuration of a smaller thickness of LCZ and a higher thickness of NCZ yields maximum LCZ temperature.

One of the most important occupational risks to healthcare workers is exposure is to blood-borne viruses. This study examined nurses’ perceptions of risk of contracting infection following single or multiple exposure to blood or body fluids. Two hundred and ninety nurses were surveyed using a questionnaire. One hundred and thirty-three responded; 85 worked in higher risk areas (ITU, Haematology, Haemodialysis and Neonatal Surgical Units) (Group A) and 48 worked in lower risk areas (medical wards, an orthopaedic and an ENT ward) (Group B). Forty-nine percent of subjects from group A and 60% of subjects from Group B believed that a needle stick injury with a needle contaminated with infected blood was an unlikely source of infection. Fifteen percent from group A and 20% from group B thought that infection with a blood-borne virus following a needle stick injury contaminated with Human Immunodeficiency Virus (HIV) infected blood was very unlikely. Twelve percent from group A and 10% from Group B did not know whether resheathing needles between use can provide protection against HIV. Sixty-seven percent from group A and 71% from group B disagreed with the statement that nurses are at higher risk of exposure to HIV/HBV than the other healthcare workers. Thirteen percent from group A and 5% from group B agreed with the statement, whereas 8% from group A and 5% from group B thought that nurses are at less risk. Only 22% from group A and 23% from group B would take more precautions if they knew that the patient had HIV/HBV infection, whilst 11% and 8% respectively admitted that they would take special precautions only when the patient has clinical symptoms of HIV/HBV infection. The findings suggest that these nurses would benefit from further education regarding infection from blood-borne viruses.

In previous works we explained theS andP-wave data on heavy quark spectroscopy for the spin-independent potential given by the combination of linear, harmonic or power-law and colour-Coulomb potentials. In the present work, we try to understand the same quarkonium spectra when the spin-independent part of the potential contains the linear potential only and the colour-Coulombic piece is treated perturbatively. We find that the present model cannot explain all the features ofS andP-wave data even at the cost of a large value of QCD scale parameter.

Recently, we have studied a flavour-independent potential for quark-antiquark systems of equal and unequal masses in which the confining interaction is scalar-vector admixture with dominant scalar interaction and the spin-dependent part of the potential has been obtained from the non-relativistic reduction of the Bethe-Salpeter kernel. This potential was found to explain the heavy-quark data well. In the present work we have obtained further affirmative tests of the model by calculating the mass spectra of higher levels as well as the confining contribution of the spin-orbit forces forL=1 states of quarkonia. We have considered the annihilation processes and radiative transitions too. The former include leptonic decay, two-photon decay, two-gluon annihilation, three-photon decay and three-gluon annihilations.

An l-asparaginase produced by Pseudomonas stutzeri MB-405 was isolated and characterized. After initial ammonium sulfate fractionation, the enzyme was purified by consecutive column chromatography on Sephadex G-100, Ca-hydroxylapatite, and DEAE-Sephadex A-50. The 665.5-fold purified enzyme thus obtained has the specific activity of 732.3 units mg protein-1 with an overall recovery of 27.2%. The apparent Mr of the enzyme under nondenaturing and denaturing conditions was 34 kDa and 33 kDa respectively, and the isoelectric point was 6.38±0.02. It displayed optimum activity at pH 9.0 and 37°C. The enzyme was very specific for l-asparagine and did not hydrolyze L-glutaminate. The Km of the l-asparaginase was found to be 1.45×10-4m towards l-asparagine and was competitively inhibited by 5-diazo-4-oxo-l-norvaline (DONV) with a Ki of 0.03mm. Metal ions such as Mn2+, Zn2+, Hg2+, Fe3+, Ni2+, and Cd2+ potentially inhibited the enzyme activity. The activity was enhanced in the presence of thiol-protecting reagents such as DTT, 2-ME, and glutathione (reduced), but inhibited by PCMB and iodoacetamide. The tumor inhibition study with Dalton's lymphoma tumor cells in vivo indicated that this enzyme possesses antitumor properties.

In this communication, we report the presence of a unique colchicine-binding activity in the polysomes of rat brain. This drug-binding property, is somewhat similar to that of tubulin isolated from many sources; however, it differs in several bio-chemical characteristics such as (i) thermal stability of colchicine-binding site, (ii) protection of binding site by vinblastine and (iii) time required for binding equilibration. Such binding of colchicine to the polysomes is most probably due to the presence of a nascent peptide chain of tubulin in the polysome.

Proteus rettgeri has been found to contain two separable 1-amino acid oxidases. Both enzymes are particulate in nature, neither being ribosomal bound. One of these enzymes appears to have broad specificity, being active toward monoaminomonocarboxylic, imino, aromatic, sulfur-containing, and beta-hydroxyamino acids. The other enzyme has more limited specificity, catalyzing the oxidative deamination of the basic amino acids and citrulline. The affinity of this oxidase for the various substrates at pH 7.6 in decreasing order is arginine, histidine, ornithine, citrulline, and lysine. This enzyme has a particularly high affinity for arginine (Km equal to 0.27 mM), and anomalous kinetics are observed with increasing substrate concentrations. When concentrations of arginine greater than 1.0mM were added to the reaction containing histidine, imidazole pyruvate formation was completely inhibited.

We investigate the features of boost-invariant hydrodynamics of Bjorken, the boost-non-invariant hydrodynamics of Srivastava et al. and the Landau hydrodynamics corresponding to the so-called stopping scenario for the ultra relativistic collision of heavy nuclei. The chemical potential has been assumed to be small, and a (1 + 1)-dimensional expansion is considered. The fluid rapidity densities for the three cases are found to be quite distinct in nature. It is shown that a rapidity shift parameter can be defined which measures the deviation of the flow from the so-called similarity flow. It is found to be dramatically different for the three hydrodynamic solutions and can be used to characterise the flow. The cooling laws for the three solutions are obtained and they reveal that the cooling is fastest for the Landau solution and slowest for the Bjorken solution. It is also seen that the initial temperatures likely to be attained at a given incident energy are largest for the Landau solution and smallest for the Bjorken solution. A number of alternative general solutions are also discussed.Copyright 1993, 1999 Academic Press

The production of amylolytic enzymes by a thermophilic cellulolytic fungus,Myceliophthora thermophila D14 was investigated by batch cultivation in Czapek-Dox medium at 45° C. Among various nitrogenous compounds used, NaNO3 and KNO3 were found to be the best for amylase production. Starch, cellobiose and maltose induced the synthesis of amylase while glucose, fructose, galactose, lactose, arabinose, xylose, sorbitol, mesoinositol and sucrose did not. Calcium ions had the most stimulating effect on enzyme formation amongst many ions investigated. The synthesis of amylolytic enzymes was dependent on growth and occurred predominantly in the mid-stationary phase. The enzyme was active in a broad temperature range (50° C–60° C) and displayed activity optima at 60° C and pH 5.6.

In order to better understand colon cancer, a model system reflecting the heterogenous nature of this disease was developed and used in the development of new cytotoxic and non-cytotoxic therapeutic approaches. A large bank of colon carcinoma cell lines was established from primary human colon carcinomas and grouped based on their tumorigenicity in athymic mice, their growth rates in soft agarose and in tissue culture, and their secreted levels of carcinoembryonic antigen. These cell lines were later characterized based on cell surface proteins and antigens detected with antisera raised against a differentiated colon carcinoma cell line. Although these biochemical markers correlated with the biological classification of these cell lines, there was still extensive heterogeneity within each group in all properties examined. This colon carcinoma cell system was used to study natural vs. selected resistance to the anticancer drug mitomycin C (MMC). The differing IC50 values in vitro were reflected in the inhibition by MMC of xenograft growth in athymic mice. A new, more readily bioactivatable analogue of MMC was tried and shown to be more active in vitro and in vivo, suggesting that rapid efflux of the drug before activation may be important in examining causes of resistance to MMC. Another approach to the treatment of colon cancer is the use of non-cytotoxic agents such as growth factors and differentiation agents to restore normal growth to the malignant cells. We have isolated and characterized two types of polypeptides from colon carcinoma cells and conditioned medium from these cells. The first, transforming growth factors (TGF's) confer a transformed phenotype on non-transformed fibroblasts while the second, tumor inhibitory factors (TIF's), inhibits the anchorage independent growth of transformed cells. The fact that extracts of colon carcinoma cells contain both activities suggests that the heterogeneity of the cell lines could be due to different levels of TGF's and TIF's produced. The effectiveness of differentiation agents to restore normal growth control using a transformed mouse embryo cell line was examined. Treatment of these cells with differentiation agents restored normal growth control to these cells. An increased synthesis of TGF's resulted from these treatments. Therefore, differentiation agents may be useful in non-cytotoxic treatment. The use of this model system for human colon carcinoma will hopefully lead to more effective drugs for the treatment of colon cancer in man.

Transport coefficients of quark-gluon plasma are discussed in the framework of relativistic kinetic theory with the relaxation time approximation of Boltzmann transport equation. The expressions for the coefficients of shear and volume viscosities and heat conductivity are derived assuming quark-gluon plasma to be a non-reactive mixture of quarks, anti-quarks and gluons. A lowest order in deviations from local thermal equilibrium and in plasma phase, lowest order in coupling constant are assumed. Entropy production due to irreversible processes is discussed.

For a large class of phenomenological potential models motivated by quantum chromodynamics, we have studied the behaviour of bound state masses as the constituent mass is increased and found that the mass of a quark-antiquark bound state increases when a constituent mass is increased. It appears, for these potentials, thatdquark is heavier thanuquark.

Using the thermodynamic model at zero temperature and a density-dependent quark mass model of confinement, the possibilities of light-quark liberation and strange-quark formation near ground-state nuclear matter have been investigated. Some thermodynamic properties of strange quark matter which may be produced at the core of neutron stars have been studied. The possibility of quark-hadron phase transition in the early Universe has also been investigated using a modified version of a density-dependent confinement mechanism at finite temperature.

The extracellular ß-glucosidase has been purified from culture broth of Myceliophthora thermophila ATCC 48104 grown on crystalline cellulose. The enzyme was purified approximately 30-fold by (NH4)2SO4 precipitation and column chromatography on DEAE-Sephadex A-50, Sephadex G-200 and DEAE-Sephadex A-50. The molecular mass of the enzyme was estimated to be about 120 kD by both sodium dodecyl sulphate gel electrophoresis and gel filtration chromatography. It displayed optimal activity at pH 4.8 and 60°C. The purified enzyme in the absence of substrate was stable up to 60°C and pH between 4.5 and 5.5. The enzyme hydrolysed p-nitrophenyl-ß-d-glucoside, cellobiose and salicin but not carboxymethyl cellulose or crystalline cellulose. The Km of the enzyme was 1.6mm for p-nitrophenyl-ß-d-glucoside and 8.0mm for cellobiose. d-Glucose was a competitive inhibitor of the enzyme with a K of 22.5mm. Enzyme K activity was inhibited by HgCl2, FeSO4, CuSO4, EDTA, sodium dodecyl sulphate, p-chloromercurobenzoate and iodoacetamide and was stimulated by 2-mercaptoethanol, dithiothreitol and glutathione. Ethanol up to 1.7 m had no effect on the enzyme activity.

A kinematical basis is proposed for form factors of the power type associated with multiple derivative couplings, on the basis of a Lorentz contraction effect on the external momenta involved in the transition matrix elements for mesons and baryons as appropriate quark composites. The argument (due to Licht and Pagnamenta) which applies separately to the Breit and c.m. frames for a decay matrix element provides a formal theoretical justification for thead hocpower form factors used by the Delhi group in a series of applications to hadronic processes over the past few years. The radius of interaction finds a natural place in this description simply from dimensional considerations, and its rather small magnitude, less than 0.5F, estimated fromfits to the data indicates a relatively small role played by structure effects. The Breit frame form factors, which work somewhat better than the c.m. frame ones (effectively used in the earlier studies), give a rather impressive sets of fits to the baryon decays in the (L + 1) wave (consistently for both vertical and horizontal) and the (L − 1) wave (mainly horizontal). The mesonic decays, the data for which are available mostly for the (L + 1) wave, are also fitted with an equal degree of consistency without any extra assumptions.

This paper consists of two parts. In the first part, the existence of Love waves in non-homogeneous and transversely-isotropic elastic layer over-lying a semi-infinite isotropic elastic solid has been investigated. The frequency equation for such waves has been derived. Numerical calculations giving the velocity of such waves has been made for different layer thicknesses. In the second part, a characteristic frequency equation has been calculated considering the lower boundary of the layer to be rigid. A numerical calculations has been made in this case also to represent the variation of wave number with velocity for different mode number.

Transforming growth factor beta 1 regulates the expression of extracellular matrix adhesion molecules and the carcinoembryonic antigen gene family of glycoproteins in the Moser colon carcinoma cell line. Expression of fibronectin antisense RNA in the Moser cells down-regulated fibronectin mRNA expression and blocked the ability of transforming growth factor beta 1 to stimulate fibronectin secretion. Cells expressing antisense fibronectin RNA exhibited a higher rate of proliferation, changed their morphology, and produced more laminin in response to treatment with transforming growth factor beta 1. The stimulation of carcinoembryonic antigen secretion by transforming growth factor beta 1 (which normally lagged 10-16 h behind that of fibronectin secretion stimulated by transforming growth factor beta 1) was blocked by the expression of antisense fibronectin RNA. Thus, the stimulation of fibronectin secretion by transforming growth factor beta 1 was a prerequisite for subsequent stimulation of carcinoembryonic antigen secretion. In addition, the stimulation of the cellular expression of carcinoembryonic antigen and three carcinoembryonic antigen cross-reactive species of glycoproteins by transforming growth factor beta 1 was down-modulated in cells expressing antisense fibronectin RNA. We therefore conclude that fibronectin may play an important role in the mechanisms of transforming growth factor beta 1 regulation of the expression of carcino-embryonic antigen gene family of glycoproteins.

The problem of concentrated line load moving with supersonic speed along the boundary of an isotropic heterogeneous medium has been solved as a plane strain problem. The stresses and displacements in the heterogeneous case considered are found to decay exponentially with distance.

Abstract: An alternative reaction route for the production of111In from rhodium target bombarded with a12C beam has been developed. Sulfate fusion was adapted for dissolution of the irradiated rhodium metal target. Indium was coprecipitated with La(OH)3 and purified by solvent extraction of the InBr3 complex into di-isopropyl ether and back extraction in 6M HCl. The chemical yield of the separation, determined using105Rh as tracer, was found to be above 90%. The radionuclidic purity of the separated111In satisfies the requirement prescribed for radiopharmaceutical preparations. The radioactivity yield achieved using this route was about 0.2 MBq/μAh.

The difference between theb andc quark masses is determined within the framework of the QCD motivated potential of De Rujula, Georgi and Glashow for heavy-light and heavy-heavy quark-antiquark systems. The values, though nearly equal, are found to differ from that obtained for heavy-heavy systems determined by other methods.

The present investigation was carried out to estimate the genetic variability and character association. Significant differences were observed among the genotypes for all the 15 traits for 20 chili genotypes. The highest genotypic coefficient of variation and phenotypic coefficient of variation were found for ten edible fruit weight, number of fruits per plant, fruit yield per plant, ten dry fruit weight, fruit length, fruit width, and weight of seeds per fruit. High heritability coupled with very high genetic advance as per cent of mean was observed for ten edible fruit weight, ten dry fruit weight, fruit length, number of fruits per plant, and fruit yield per plant. Phenotypic correlation coefficient among different traits indicated that fruit yield per plant at green stage had significant and positive association with ten edible green fruit weight, number of primary branches, harvest duration, and first fruit maturity and significant negative correlation with days to first picking. The path coefficient analysis revealed that days to first picking had the maximum positive direct effect on fruit yield per plant followed by harvest duration, ten edible fruit weight, ten dry fruit weight, hundred-seed weight, number of fruits per plant, first fruit maturity, and number of primary branches. Days to first picking had the maximum positive direct effect but significant negative effect with fruit yield per plant which indicated that the trait should be selected to expunge the undesirable indirect effect in order to make use of the direct effect. Therefore, selection should be practiced for ten edible fruit weight, ten dry fruit weight, number of fruits per plant, harvest duration, and hundred-seed weight for direct improvement of fruit yield per plant.

Gibberellic acid (GA), a plant hormone stimulating plant growth and development, is a tetracyclic di-terpenoid compound. GAs stimulate seed germination, trigger transitions from meristem to shoot growth, juvenile to adult leaf stage, vegetative to flowering, determines sex expression and grain development along with an interaction of different environmental factors viz.,light, temperature and water. The major site of bioactive GA is stamens that influence male flower production and pedicel growth. However, this opens up the question of how female flowers regulate growth and development, since regulatory mechanisms/organs other than those in male flowers are mandatory. Although GAs are thought to act occasionally like paracrine signals do, it is still a mystery to understand the GA biosynthesis and its movement. It has not yet confirmed the appropriate site of bioactive GA in plants or which tissues targeted by bioactive GAs to initiate their action. Presently, it is a great challenge for scientific community to understand the appropriate mechanism of GA movement in plant’s growth, floral development, sex expression, grain development and seed germination. The appropriate elucidation of GA transport mechanism is essential for the survival of plant species and successful crop production.

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