goltapeh

Zymoseptoria tritici, is a species of filamentous fungus and causes the widespread wheat disease Septoria tritici blotch (STB). Salicylic acid has a key role in plant defence reactions and is also involved in the induction of systemic acquired resistance. However, the contribution of SA to the interaction of Z. tritici -wheat in STB is not entirely clear.In this study, it was shown that the Z. tritici mycelial growth and conidia germination were significantly inhibited the presence of increasing concentration of SA in both liquid and solid media. In addition, the effect of SA on pathogenicity of Z. tritici in wheat was investigated. In this study, the inhibitory effect of SA on Z. tritici at different concentrations (1 to 20 mM) in vitro, and also, the efficacy of its exogenous application in the suppression of STB in wheat under the greenhouse condition were investigated. In vitro evaluation was done on YMDA and YMDB to determine the effect of SA on the germination of conidia and growth of mycelium, respectively. Susceptible bread wheat cultivar was grown in pot and inoculated with fungus spores and SA in a three-leaf stage for green house experiments. The results showed that the germination ofconidia was completely inhibited by 4 mM SA. Furthermore, in modified YMDA plates at over 0.8 mM, the colonies diameter was reduced significantly. The result of in planta assay indicated that the foliar application of 4 mM SA can significantly reduce the disease symptoms on the wheat leaves. Discussion and conclusion: Regarding our data, it seems that SA shows more inhibitory effect in in vitro experiments than in planta. Moreover, according to the positive effects of SA on STB, the survey results can be considered as a potential approach in the management of this disease.

Induced resistance is one the ways by which plants cope with the biotic stresses. Pathogenesis-related proteins (PRs), including chitinase and β-1,3-glucanase are synthesized by plant in response to pathogenic infection. In present work, we have carried out inoculation experiment in wheat to investigate the effect of salicylic acid (SA) and Pseudomonas flourescens on Septoria tritici Bloch (STB) symptoms. Subsequently, the expression profiles of chitinase and β-1,3-glucanase were analyzed with semi-quantitative RT-PCR at 0, 4, 14 and 24 days after inoculation in both treated and control plants. Results showed that the expression of both chitinase and β-1,3-glucanase genes increased in interaction with Z. tritici and the application of SA and P. flourescens. On the other hand, the application together had no significant effect on gene expression. Briefly, it can be concluded that increment of chitinase and β-1,3-glucanase expression level with the application of SA and P. flourescens would play role induction of plant defense against STB.

In this study¡ response of 18 bread wheat cultivars were evaluated in interaction with five Mycosphaerella graminicola isolates from five provinces in seedling stage. In this experiment¡ the seeds were treated by 0¡ 0.75 and 1 mM concentrations of salicylic acid. According to the analysis of variance¡ significant difference (p

Culture filtrates (CF) of two species of the nematophagous fungi, Arthrobotrys oligospora and Arthrobotrys conoidesat three concentrations (25%, 50% and 100%) of stock, were tested on the mortality of second stage juveniles (J2) and egg hatching rate of Meloidogyne incognita and Meloidogyne javanica. Results showed that the percent juvenile mortality was directly proportional to concentration of the filtrates. Egg hatching rate of these nematodes was inversely affected by increasing concentrations. Also CFs had various impacts on the mortality of J2 and egg hatching rate. In case of M. incognita maximum J2 mortality (28.98%) occurred after 24 hours of exposure to A. conoides filtrate at concentration of 100%. The minimum toxicity (12.5% J2 mortality) was recorded for A. oligospora at 25% filtrate concentration. At the same time, the highest rate of J2 mortality of M. javanica (19.18%) belonged to the 100% concentration of A. conoides, while minimum toxicity belonged to 25% concentration of A. oligospora causing 9.09% mortality. Maximum egg hatching rate for M. incognita (30.75%) belonged to control and minimum hatching rate (1.25%) belonged to 100% concentration of A. conoides. The highest hatching rate of M. javanica (36.25%)belonged to control and minimum hatching rate (1.25%) occurred at 100% concentration of A. conoides.

Transferring foreign genes into mushroom mediated by Agrobacterium tumefaciens is a standard technique in genetic engineering. Recombinant human insulin has been greatly used in the treatment of type I diabetes. The production of edible mushroom derived insulin should facilitate oral delivery. In this study we used the Agrobacterium tumefaciens mediated transformation method for the transfer and expression of the cholera toxin-B subunit (CTB) fused with human pro-insulin (Pins) in the edible oyster mushroom، Pleurotus ostreatus. The binary vector pCAMBIA1304 harboring CTB-Pins gene driven by the P. ostreatus gpd promoter was constructed and introduced into P. ostreatus via Agrobacterium tumefaciens mediated transformation. Optimization of gene transformation and tissue culture conditions is one of the most important issues in transgenic mushroom production. For attaining optimized conditions، the effects of co-cultivation conditions، Agrobacterium strains and the concentration of Agrobacterium cell suspensions were studied. Integration of CTB-Pins into mushroom genome was confirmed by PCR. The successful transformation to oyster mushroom suggests that the proposed modified transformation system is apparently useful for the production of human pro-insulin in these edible mushrooms.