RESUMEN
For the purpose of the current study, hairy root induction in S. bornmuelleri, which is an important medicinal plant, was examined using a particular protocol. Accordingly, some factors such as four strain types of Agrobacterium rhizogenes (A4, A13, MSU440 and ATCC15834), three different explants, namely stem, petiole and leaf, two co-cultivation media, i.e. full and half-MS were studied. Besides, two inoculation methods including injection and immersion as well as three inoculation times (5, 7 and 10 min) were closely taken into account. Utilizing injection method by MSU440 strain, hairy root induction took place in stem explants, and a remarkable increase in transformation frequency (100%) was observed in half-strength MS medium. Methyl jasmonate (MeJA, 100 µM), methyl-b-cyclodextrin (b-CD, 0.7, 7 and 14 mM) and Chitosan (Chi, 50, 100 and 200 mg/l) were used either individually or in a combined way to elicitation. Based on the HPLC results, production of chrysin, wogonin and baicalein increased 9.15, 10.56 and 13.25 times after elicitation of hairy roots by MeJA + Chi. In addition, transcripts of FNSÐ2 and MYB7, two important genes involved in the flavonoid biosynthesis pathway, were studies. By applying Chi and MeJA + Chi elicitor, the expression of both genes increased noticeably. It can be concluded that the mentioned hairy root culture system of S. bornmuelleri can be an alternative to flavonoids production. Moreover, there is a direct and positive relationship between the expression of FNSÐ2 and MYB7 genes as well as the level of three flavonoids.
Asunto(s)
Agrobacterium , Interacciones Huésped-Patógeno , Scutellaria , Factores de Transcripción , Agrobacterium/fisiología , Flavonoides/genética , Regulación de la Expresión Génica de las Plantas , Interacciones Huésped-Patógeno/genética , Raíces de Plantas/crecimiento & desarrollo , Raíces de Plantas/microbiología , Scutellaria/genética , Scutellaria/microbiología , Factores de Transcripción/genética , Factores de Transcripción/metabolismoRESUMEN
Entomopathogenic fungi with approximately 1000 known species are key regulatory factors in insect pest population. Also, these agents infect insects by direct penetration of the cuticle and thus provide the only practical means of microbial control of insects that feed on plant or animal juices as well as for the many coleopterans and orthopteran pest which have very few known viral or bacterial diseases. Beauveria bassiana is a widespread entomopathogenic fungi that infect many insect species. The aim of the current study was to determine the effect of different composition of oil in pathogenicity of the fungus. So, the fungus was grown on Potato dextrose agar (PDA) at 25 degrees C. Conidia were harvested from 14-day sporulating cultures by scraping the surface with a spatula and suspending the conidia in sterile 0.03% aqueous Tween 80. The number of conidia was determined using an improved Neubauer haemocytometer and spore concentrations of 10(4), 10(5), 10(6), 10(7), 108 and control were prepared. Two controls were done one was different concentrations of spore without oil and the other only oil. The insects were collected from the wheat farm in and maintained on wheat plants in the laboratory at 27+/-2 degrees C under a 14 h light: 10 h dark (LD 14:10) photoperiod. Assays were done with dipping methods. The results showed that there are significant differences in mortality of insects in two spore emulsions, one oil formulated and the other spores in sterile water without oil usage. Oil formulation enhances fungal virulence toward insect. Since insect cuticle especially epicuticle (lipid layer) is the primary site of establishment of mycosis, oil formulation increase the adhesion of spore to the insect cuticle through hydrophobic interaction between the spore and cuticle surface.