Biogenic iron oxide nanoparticles enhance callogenesis and regeneration pattern of recalcitrant Cicer arietinum L.

This study is the first report on the biosynthesized iron oxide nanoparticles (IONPs) which mediate in-vitro callus induction and shoot regeneration in economically important recalcitrant chickpea crop (Cicer arietinum L.). Here, we used leaf extract of Cymbopogon jwarancusa for the synthesis of IONPs in order to achieve a better biocompatibility. The bioactive compounds in C. jwarancusa leaf extract served as both reducing and capping agents in the fabrication process of IONPs. Field emission scanning electron microscopy (FE-SEM) revealed rods like surface morphology of IONPs with an average diameter of 50±0.2 nm. Energy-dispersive X-ray spectroscopy (EDS) depicted formation of pure IONPs with 69.84% Fe and 30.16% O2. X-ray diffractometry (XRD) and attenuated total reflectance-fourier transform infrared (ATR-FTIR) validate the crystalline structure, chemical analysis detect the presence of various biomolecular fingerprints in the as synthesized IONPs. UV-visible absorption spectroscopy depicts activity of IONPs under visible light. Thermo-gravimetric analysis (TGA) displayed thermal loss of organic capping around 500°C and confirmed their stabilization. The biosynthesized IONPs revealed promising results in callus induction, shoot regeneration and root induction of chickpea plants. Both chickpea varieties Punjab-Noor 09 and Bittle-98 explants, Embryo axes (EA) and Embryo axes plus adjacent part of cotyledon (EXC) demonstrated dose-dependent response. Among all explants, EXC of Punjab-Noor variety showed the highest callogenesis (96%) and shoot regeneration frequency (88%), while root induction frequency was also increased to 83%. Iron content was quantified in regenerated chickpea varieties through inductively coupled plasma-optical emission spectrometry. The quantity of iron is significantly increased in Punjab-Noor regenerated plants (4.88 mg/g) as compare to control treated plants (2.42 mg/g). We found that IONPs enhance chickpea growth pattern and keep regenerated plantlets infection free by providing an optimum environment for rapid growth and development. Thus, IONPs synthesized through green process can be utilized in tissue culture studies in other important recalcitrant legumes crops.

The Role of Saccharides in the Mechanisms of Pathogenicity of Fusarium oxysporum f. sp. lupini in Yellow Lupine (Lupinus luteus L.)

The primary aim of this study was to determine the relationship between soluble sugar levels (sucrose, glucose, or fructose) in yellow lupine embryo axes and the pathogenicity of the hemibiotrophic fungus Fusarium oxysporum f. sp. Schlecht lupini. The first step of this study was to determine the effect of exogenous saccharides on the growth and sporulation of F. oxysporum. The second one focused on estimating the levels of ergosterol as a fungal growth indicator in infected embryo axes cultured in vitro on sugar containing-medium or without it. The third aim of this study was to record the levels of the mycotoxin moniliformin as the most characteristic secondary metabolite of F. oxysporum in the infected embryo axes with the high sugar medium and without it. Additionally, morphometric measurements, i.e., the length and fresh weight of embryo axes, were done. The levels of ergosterol were the highest in infected embryo axes with a sugar deficit. At the same time, significant accumulation of the mycotoxin moniliformin was recorded in those tissues. Furthermore, it was found that the presence of sugars in water agar medium inhibited the sporulation of the pathogenic fungus F. oxysporum in relation to the control (sporulation of the pathogen on medium without sugar), the strongest inhibiting effect was observed in the case of glucose. Infection caused by F. oxysporum significantly limited the growth of embryo axes, but this effect was more visible on infected axes cultured under sugar deficiency than on the ones cultured with soluble sugars. The obtained results thus showed that high sugar levels may lead to reduced production of mycotoxins by F. oxysporum, limiting infection development and fusariosis.

DE NOVO REGENERATION IN CHICKPEA GENOTYPES (CICER ARIETINUM L.)

Direct regeneration from mature embryo axes was achieved without intervening of callus phase in four chickpea varieties on the Media MS and B5 supplemented with combination of BAP, NAA and Kinetin. Hundred percent regeneration capacity was exhibited by commercially grown Vijay and Vishal varieties. There was considerable variation in umber of multiple shoot production by different varieties. Profuse rooting was obtained on the medium containing 0.5 and 1.0 mg/l IBA. This protocol is optimized for complete plant regeneration of chickpea for genetic transformation.

Qualitative changes and dynamics of protein synthesis during cold and warm stratification of Norway maple (Acer platanoides L.) seeds

Protein synthesis in cotyledons and embryo axes of Norway maple (<em>Acer platanoides</em> L.) was studied in seeds stratified at 3 or 15^oC. At 3^oC stratification, germination of seeds starts after 9 weeks, at 15^oC stratification germination does not occur. The changes of protein synthesis level in both temperatures had two phasic character. In embryo axes (3 and 15^oC) protein synthesis grow up, but in cotyledons (3^oC) synthesis of proteins decrease. Generally, activity of protein synthesis was higher at 3^oC, as like as DNA level was higher. After imbibition, in cold and warm stratification, in embryo axes, many new protein are become visible. We expect, that two from this proteins, determined as A and B my be connected with the releasing from dormancy. In seeds stratified at 15^oC, these proteins are occuring in vestigal amount or are completely absent.

Activity ATPases during dormancy breaking in Norway maple (Acer platanoides L.) seeds

The activity of ATPases was studied in embryo axes and cotyledons of Norway maple seeds stratified at 3^oC (dormancy broken) and 15^oC (dormancy not broken). The activity of mitochondrial (F. III) and activity connected with all cellular membranes (F. Il) and soluble fraction (F. I) ATPases was investigated. It was found that mitochondrial ATPases are the most active. The activity of all types of ATPases is greater in seeds stratified at 3^oC. It increases during seed dormancy breaking, particularly in the case of mitochondrial ATPases. The rise in the activity of mitochondrial and others ATPases in embryo axes of seeds stratified at 3^oC is stepwise. In seeds stratified at 15^oC ATPase activity generally decreases.