Journal of Plant Biological Sciences
Year:2013 | Volume:5 | Issue:15|Papers Count:9

Common bean belongs to Fabaceae and the subfamily of Lotoideae. It is the most important species of the grain family with noticeable economic importance in human's nutrition. Regeneration from tissue culture is one of the most suitable and effective procedures for preservation and reproduction of the plants. In this investigation, induction of callus, shoot and root has been studied in common bean (Phaseolus vulgaris L. cv. Goli) under different concentrations of a-Naphthalene acetic acid and Benzyl amino purine. First, the seeds were surface sterilized and transferred to suitable medium to achieve sterile seedlings. After 10 days, explants (hypocotyl, root and leaf) from sterile seedlings were tested in 25 various hormone treatments. For induction of organogenesis, explants were transferred to solid Morashige and Skoog medium supplemented with 30 g/lit sucrose, B5 vitamins and different concentrations of a-Naphthalene acetic acid (0, 0.1, 0.2, 0.4 and 0.8 mg/lit) and Benzyl amino purine (0, 0.5, 1, 2 and 4 mg/lit). Our data showed callus induction achieved in combination of two hormons: (0.4 mg/lit a-Naphthalene acetic acid and 2 mg/lit Benzyl amino purine). Induction of shoot increased with increasing concentrations of Benzyl amino purine to 2 mg/lit and then decreased. Induction of roots increased with increasing a-Naphthalene acetic acid concentrations. Furthermore, the level of internal auxin in common bean was high because the explants rooted in the minimum concentration of a-Naphthalene acetic acid. Subsequently, complete seedlings were transferred to the soil for further investigations.

Salinity is a common abiotic stress that affects plant growth and development as well as crop production in most parts of the world. To study the effects of salt stress and salicylic acid pretreatments on the growth parameters, photosynthetic pigments, photochemical efficiency of photosystem II including: quantum yield of PS II (Æ PSII), maximum quantum yield of PS II (F v/ F m) and non-photochemical quenching (NPQ) and mineral nutrients (Na+, K+, N, P, Ca2+, Mg2+, Fe, Zn2+, Mn, Cu and B) of Zea mays L. (KSC704) a factoriel experiment was conducted in completely randomized design (salinity in tow levels and salicylic acid in three levels) with 5 replicates. Salt stress reduced growth parameters and photosynthetic pigments (chl a, b and total), carotenoids, quantum yield of PS II (Æ PSII), maximum quantum yield of PS II (F v/ F m) and increased non-photochemical quenching (NPQ). Moreover, salt stress affected mineral elements in the leaves of the plants. Salinity decreased the amounts of K+ and Cu and increased Na+, P, Ca2+, Mg2+, Fe, Zn2+, Mn and B but the contents of N and Ca2+ were not affected by salinity. SA pretreatment increased photosynthetic pigments and carotenoids, quantum yield of PS II (Æ PSII), maximum quantum yield of PS II (F v/ F m) and decreased non-photochemical quenching (NPQ). SA application changed the absorption and translocation of mineral elements in the leaves and specifically decreased Na content. Positive effects of SA pretreatment appeared in reduction of salt stress and improving the plants growth.

In this study, flowers of Alhagi pseudoalhagi were structurally investigated with respect to cell-tissue manners in several developmental stages. Flowers had synsepalous calyx, papilionoid corolla and dark color wings with outstanding epidermal cells, attached keels which made closed corolla with vexillium, diadelphous and heteromorphy androecium. None of the organs had protective or secretary hairs. Anther characters were: tetras orange, extrorse, longitudinal dehiscence, four wall layers (dicotyledonous) and secretory tapetum. Epidermal and subepidermal layers of calyx, corolla, ovary and attaching tissue of anther had phenolicic (tanin) and fatty based materials. Gynoecium was monocarpellate and epigynous, with anatropous and crassinucelate ovules, open style and disk shaped stigma. After miosis cytokinesis was simultaneous. When microspores were in mature stage embryo sac had not yet passed mitosis and nucleus were not made totally.

In this survey, a floristic study was carried out in Galali iron mine. Galali mine is located in 58 Km northwest Hamedan, frontier Hamedan, Kermanshah, Sanandaj and at 47’ 54' longitude and 34’ 59' latitude. The method of plant collection in this region was classical method of regional floristic studies. Collecting plants were recognized and determined as families, genera and species by using of taxonomic method and required references. The collecting samples in this study were preserved in Herbarium of Bu-Ali Sina University. The life form of plant species was determined by Raunkier’s method. This survey showed that in Galali iron mine, there were 36 families, 116 genera and 147 species and sub species units. Asteraceae, Brassicaceae, Poaceae, Fabaceae and Lamiaceae families had the most frequency. The life forms of plants included: phanerophytes (1%), cryptophytes (5%), hemicryptophytes (49%), chamaeophytes (6%) and, therophytes (39%). The highest geographical distribution was Irano-Turanian.

Magnetic field is an environmental factor for living organisms which affects biological processes in different ways. Living cells contain electrical charges which are produced by free ions or radicals. Magnetic fields can influence cells via interaction with ions and especially ferromagnetic materials, like iron. In this study, parsley or Petroselinum crispum cells were treated by static magnetic field (30 mT, for 4 hours) and the total content of iron, ferritin and the activity of ascorbate peroxidase, superoxide dismutase and catalase were assayed. Results showed a significant decrease in the total iron content and it was followed by a decrease in ferritin content. Ascorbate peroxidase activity was reduced. It could be resulted by decrease of iron as a structural element. However, superoxide dismutase and catalase activity increased in response to magnetic field compared to the control cells. It seemed that catalase activities increased scavenge H2O2 produced by increasing superoxide dismutase activity.

Onobrychisis one of the important forage legume, which most of its wild species grow in Iran. In order to study of the effect of different salinity levels on percentage and rate of seed germination and also fresh and dry weights of seedlings in 3 Onobrychis species (O. subnitens, O. viciifolia and O. melanotricha), an experiment was carried out in three replicates using a factorial design with 5 treatments including 0 (control), 50, 100, 200 and 400 Mm NaCl. Results showed that as salinity increased, germination rate decreased in all species and was completely stopped in 400 mM NaCl. Results from mean comparison of fresh and dry weights of seedlings under salt stress showed that these parameters declined until 200 mM NaCl and there was a significant difference between different salinity levels. Results from guantitative and qualitative studies of proteins indicated that salt srtess decreased peroxidase and polyphenol oxidase activities, but increased total protein content. In addition, free proline content increased in response to salinity stress in the studied species, which was used for osmotic regulation.

Root cap cells of plant species undergo different developmental changes. In the present study, the ontogeny of the root cap cells of Pisum sativum L. was studied. The root tips of 3-day-old seedlings were immersed in primary fixative containing 1.5% (w/v) paraformaldehyde and 2% (v/v) glutaraldehyde in 100 mM phosphate buffer prior to being transferred to a secondary fixative containing 1% (w/v) osmium tetroxide. The fixed materials were embedded in London white resin and 60 nm thick sections were studied using a transmission electron microscope (TEM). The cells of columella were evident under the meristem zone by showing characteristics typical of statocytes. In these cells, a large nucleus occupied a position at the proximal cell pole, whereas the plentiful amyloplasts and endoplasmic reticulum were placed at the distal cell pole. The cells differentiated to the secretory cells as they were shifted to the peripheral side of the root cap. The cells became larger and their nucleoplasmic ratio was reduced. Concurrently, the quantity of membranes of vesicular-tubular endoplasmic reticulum and Golgi dictyosomes increased. Consequently, all of the organelles were moved to the peripheral sides of the cytoplasm and an organelle-free zone in the upper side of the cells was formed. In the next step, a number of endoplasmic reticulum membranes surrounded the organelle-free zone in order to form the central vacuole. Therefore, endoplasmic reticulum could be considered as the origin of vacuole in the root cap cells of Pisum sativum. The growth of vacuole was the last ontogenetic stage in the cells, which finally sloughed off from the root cap.

This study was carried out to assess and compare three pistachio cultivars (Ahmadaghaii, Ohadi and Kallehghuchi) on two rootstock (Mutica, Ahli) in relation to PAL activity, phenolic, flavonoid and anthocyanin in leaves, flowers, fruits and selection of the most suitable and compatible rootstock and scion in order to obtain resistance to environmental stresses. The results showed increased PAL activity, total phenolic and flavonids and also positive correlation was observed between PAL activity and the existing compounds on leaves and flowers in Mutica-Ahmadaghaii, that showed a better resistence this than the others in environmental stresses. PAL activity and total phenolic in fruits of pistachio suffered a decreased when the maturation processes began. The hulls of the pistachio fruits, contained high level of phenolic compounds, (especially in Mutica-Ahmadaghaii) which may function as a protective layer and protective chemical against ultraviolet radiation and pathogen. The final concentration of phenolic compounds and flavonoids and antocyanins in the kernel, depended on the PAL activity in kernel’s cultivar. Our results indicated the presence of a number of bioactive compounds in kernel and the highest amount belonged to Mutica-Ahmadaghai. The results of this study showed that rootstock may affect the antioxidant compound in kernel in pistachio tree.

Water deficit is one of the major abiotic stresses which adversely affects plant growth and crop yield. In this study, the changes in the activity of antioxidant enzymes, growth parameters, proline and H2O2 contents and the rate of lipids peroxidation in terms of malondialdehyde in shoot and root tissues of three chickpea cultivars (Bivanij, Jam and Arman) under dry stress were investigated. Compared to the controls, dry stress resulted in the reduction of dry weights of the shoot and the root tissues in the studied three chickpea cultivars while magnitude of decrease was greater in jam cultivar comparee to the other two cultivars. Dry stress caused significant changes in proline, and Malondialdehyde (MDA) levels in shoot tissues in the studied cultivars. Bivanij and Arman cultivars also showed higher activities of ascorbate peroxidase, proxidase, catalase and glutathione reductase in the shoot tissues in comparison with jam. These higher antioxidant activities may help the tolerant cultivars to decrease oxidative damages of dry stress to membrane lipids as compared with sensitive cultivar. On the basis of results of this study, it can be concluded that: (1) Bivanij and Arman were tolerant but Jam was sensitive to dry stress (2) dry tolerance of Bivanij and Arman cultivars might be closely related to the increased capacity of the antioxidative system to scavenge reactive oxygen species and thus suppress lipid peroxidation under dry stress.