Molecular cloning,sequence analysis and tissue expression of translationally controlled tumour protein from the WSSV‐infected Indian shrimp Penaeus indicus

The gene coding for translationally controlled tumour protein (TCTP) was polymerase chain reaction amplified from haemocyte cDNA of Indian shrimp, Penaeus indicus, and sequenced. The N‐terminal region, a conserved one among all the TCTPs, was shown to have one substitution at position 37, in the Indian isolate. Besides this, there were two substitutions in the C‐terminal region (135, 149), exclusive to the Indian isolate. Phylogenetic analysis suggested a close relatedness of TCTP from P. indicus to Fenneropenaeus chinensis compared with other isolates. Translationally controlled tumour protein gene expression was found to be elevated in the haemocytes of WSSV‐infected shrimps compared with the uninfected ones. However, tissues from the infected shrimps did not exhibit any detectable levels of TCTP expression.     

Genetic stability of long-term micropropagated Opuntia ficus-indica (L.) Mill. plantlets as assessed by molecular tools: Perspectives for in vitro conservation

Randomly amplified polymorphic DNA markers (RAPD) were employed to assess the level of genetic stability of long term micropropagated prickly pear (Opuntia ficus-indica) plantlets.Thirteen micropropagated plantlets were chosen from a clonal collection of shoots that originated from a single mother shoot. This clonal collection had been maintained under in vitro culture conditions for at least 5 years, as achieved for the time by axillary branch multiplication in Opuntia ficus-indica.Twenty arbitrary primers were used to compare RAPD patterns between in vitro raised material and the mother plant. Only 11 primers were found to yield distinct and reproducible amplification products resulting in a total of 87 amplified products, out of which 82 bands were monomorphic across all the plantlets and 5 showed polymorphisms.Cluster analysis performed on the basis of similarity indices indicated that all micropropagated plantlets and their mother plant grouped together in one major cluster with a 91% level of similarity.Low level of genetic variation has been detected, as polymorphic bands accounted for just 2.79% of the total genetic variation. This very low level of genetic variation, despite more than 5 years of in vitro culture, demonstrates the genetic stability of Opuntia ficus-indica and indicates that the axillary branch multiplication method is highly reliable for the multiplication of genetically true-to-type plant material.The high degree of clonal fidelity detected here, recommend the use of axillary-branching micropropagation technique for the safe in vitro conservation of prickly pear interesting genetic resources.     

Über die Polyphenoloxydase bei gesunden sowie von Rotylenchulus reniformis Lin. et Ol. und Meloidogyne incognita Chit. (Nematoda) befallenen Tomaten

Assay of polyphenol oxidase activity in relation to infection with the reniform nematode, influence of reducing and oxidizing agents and the enzyme activity level inRotylenchulus reniformis- andMeloidogyne incognita-tomatoes were conducted in this study. Polyphenol oxidase activity was greater inR. reniformis-infected than in uninfected roots, but was less in tissues treated with ascorbic acid and glutathione reducing agents than in healthy or in tissues treated with copper oxychloride oxidizing agent. In uninfected roots, activity of polyphenol oxidase was nearly equal to that inR. reniformis infected tissues treated with copper oxychloride. Best plant growth was observed with copper oxychloride which was associated with the least soil and root numbers ofR. reniformis. The enzyme activity in tissues infected withR. reniformis was much higher than in those parasitized withM. incognita. This activity in either nematode infected tissue was higher than that noticed in healthy tissues. This work demonstrated the occurrence of altered metabolism uponR. reniformis infection, involvement of the oxidation-reduction physiological processes anti/pro nematode buildup as well as the detection of noticeable differences in polyphenol oxidase activity whenR. reniformis orm. incognita was present.