Larvicidal Properties of Datura Stramonium (Jimson Weed) and Nicotiana Tabaccum (Tobacco) Extracts against the Larvae of (Anopheles and Culex) Mosquitoes

Extracts of the leaf of Nicotiana tabaccum (Tobacco) (L) in the familySolanaceace and the root of Datura Stramonium (Jimson weed) in the familySolanaceace, were prepared from plant materials collected within Ekiti State,Nigeria. With Datura stramonium extract treatment, there was less than 50%mortality of larvae on culicine species for the first 24hours, at 100%concentration, there was 100% death rate. On Anopheline species, there wasmore than 70% mortality rate and 100% concentration recording 90%mortality rate. This work demonstrates the potency of Nicotiana tabaccumand Datura stramonium extracts in the control of mosquito larvae. Thehighest potency was recorded in Tobacco and on Anopheline larvae whichalso is a main malaria vector. There was high correlation between the twoplant extracts on Anopheline larvae (0.93 and 0.68) at the hours of 24 and 48 but at the hour of 72, there was low correlation (0.41). Key words: Extracts, Datura stramonium, Nicotiana tabaccum, Culex,Anopheles mosquito

Bacterial RuBisCO Is Required for Efficient Bradyrhizobium/Aeschynomene Symbiosis

Rhizobia and legume plants establish symbiotic associations resulting in the formation of organs specialized in nitrogen fixation. In such organs, termed nodules, bacteria differentiate into bacteroids which convert atmospheric nitrogen and supply the plant with organic nitrogen. As a counterpart, bacteroids receive carbon substrates from the plant. This rather simple model of metabolite exchange underlies symbiosis but does not describe the complexity of bacteroids' central metabolism. A previous study using the tropical symbiotic model Aeschynomene indica/photosynthetic Bradyrhizobium sp. ORS278 suggested a role of the bacterial Calvin cycle during the symbiotic process. Herein we investigated the role of two RuBisCO gene clusters of Bradyrhizobium sp. ORS278 during symbiosis. Using gene reporter fusion strains, we showed that cbbL1 but not the paralogous cbbL2 is expressed during symbiosis. Congruently, CbbL1 was detected in bacteroids by proteome analysis. The importance of CbbL1 for symbiotic nitrogen fixation was proven by a reverse genetic approach. Interestingly, despite its symbiotic nitrogen fixation defect, the cbbL1 mutant was not affected in nitrogen fixation activity under free living state. This study demonstrates a critical role for bacterial RuBisCO during a rhizobia/legume symbiotic interaction