جستجوی مقالات مرتبط با کلیدواژه « cellular immunity » در نشریات گروه « گیاهپزشکی »

Virulence of the two Iranian isolates of Beauveria bassiana was evaluated against the larvae of Hyphantria cunea through bioassay and immune responses. The median lethal concentrations (LC50) for AM-118 and BB3 isolates calculated as 8.8×105 and 2.3×106 spore/mL. by using dipping method. The LT50 values were calculated as 3.94 and 5.78 days, respectively for AM-118 and BB3 isolates. The highest numbers of the total hemocytes, granulocytes, and plasmatocytes were observed 3-6 hours post-injection of both fungal isolates. On the other hand, the total number of hemocytes increased from 160×104 to 480×104 cell/mL and the numbers of granulocytes and plasmatocytes increased to 200×104 and 140×104 cell/mL, respectively. The larvae injection by the conidia of AM-118 and BB3 led to the increase of nodule numbers at time intervals of 12-24 hours and the activity of phenoloxidase after 6-12 hours of post-injection from 0.12 to 0.2 U/mg protein. The isolate AM-118 showed the higher virulence compared to BB3 and it caused the more mortality in the lower time and spore concentrations. Moreover, the immune responses of the larvae toward this isolate were lower than BB3 isolate. The current results demonstrate that the two Iranian isolates of the entomopathogenic fungus, B. bassiana, are virulent against the larvae but they induce immune responses indicating physiological conflict between the pathogen and host.

The eggs and larvae of the Mediterranean flour moth, Ephestia kuehniella (Zell.), are widely used to rear parasitoids and predators for biological control programs. In this study, nutritional responses and digestive enzymes activities of the fourth instar larvae, as well as some immunological parameters of E. kuehniella, were studied on the diet containing casein and zein proteins under laboratory conditions. The fourth larval instar reared on diet containing casein had the highest relative rate of consumption (5.9 ± 0.2) and relative growth rate (11.3 ± 0.3). The highest and the lowest activity of lipase, tripcine, elastase, carboxypeptidase and aminopeptidase in larvae fed were on casein and zein proteins. In the immunological study, injection of tween and Beauveria bassiana (Balsamo) Vuillemin in larvae treated by casein protein significantly increased the total number of hemocyte and the number of granulocytes and plasmatocytes. This study indicated that the nature of the protein in the diet effects on physiological mechanisms of feeding and affect the immune response.

In this study, the effects of two isolates from the entomopathogenic fungus, Beauveria bassiana Boisduval were determined in immune system of the predatory hemipteran, Andrallus spinidens Fabricius (Hemiptera: Pentatomidae). Four types of hemocytes were identified in the hemolymph of the adult bug including prohemocytes, plasmatocytes, granulocytes and oenocytoids. Also, the effects of two entomopathogenic fungus isolates and latex bead were studied on the activity of phenoloxidase. The highest number of total hemocytes were found at time intervals of 12, 12, 48 and 48 hours post-injection by Tween80 (Control), latex bead, BB2 and AM-118, respectively. The highest number of plasmatocytes were determined 48, 48, 24 and 3 hours post-injection by Tween80 (Control), latex bead, BB2 and AM-118 but the number of granulocytes were observed after 48, 48, 12 and 12 hours, respectively. The highest number of nodules were observed 48, 48, 12 and 6 hours post-injection Tween80 (Control), latex bead, BB2 and AM-118, respectively. The highest activity of phenoloxidase were determined 6 hours post-injection by Tween80 (Control), BB2 and AM-118 and 3 hours post-injection by Tween80, respectively. To determine the gene of proPhenoloxidase, RNAs of the hemocytes were extracted and it was amplified by a pair of degenerate forward and reverse primers followed by cDNA synthesis. The results revealed a product with 675 bp based on reverse sequencing which had a 66% similarity with prophenoloxidase of Anasa tristis De Geer.Results of this study demonstrate that immune responses of the predacious hemipteran are different regarding various isolates of B. bassiana so the isolates should be used which have the lower virulence against the predator in integrated pest management programs.