3 research outputs found
Virus-induced gene silencing in Catharanthus roseus by biolistic inoculation of tobacco rattle virus vectors
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A BAHD acyltransferase catalyzing 19-O-acetylation of tabersonine derivatives in roots of Catharanthus roseus enables combinatorial synthesis of monoterpene indole alkaloids
While the characterization of the biosynthetic pathway of monoterpene indole alkaloids (MIAs) in leaves of Catharanthus roseus is now reaching completion, only two enzymes from the root counterpart dedicated to tabersonine metabolism have been identified to date, namely tabersonine 19-hydroxylase (T19H) and minovincine 19-O-acetyltransferase (MAT). Albeit the recombinant MAT catalyzes MIA acetylation at low efficiency in vitro, we demonstrated that MAT was inactive when expressed in yeast and in planta, suggesting an alternative function for this enzyme. Therefore, through transcriptomic analysis of periwinkle adventitious roots, several other BAHD acyltransferase candidates were identified based on the correlation of their expression profile with T19H and found to localize in small genomic clusters. Only one, named tabersonine derivative 19-O-acetyltransferase (TAT) was able to acetylate the 19-hydroxytabersonine derivatives from roots, such as minovincinine and hörhammericine, following expression in yeast. Kinetic studies also showed that the recombinant TAT was specific for root MIAs and displayed an up to 200-fold higher catalytic efficiency than MAT. In addition, gene expression analysis, protein subcellular localization and heterologous expression in Nicotiana benthamiana were in agreement with the prominent role of TAT in acetylation of root-specific MIAs, thereby redefining the molecular determinants of the root MIA biosynthetic pathway. Finally, identification of TAT provided a convenient tool for metabolic engineering of MIAs in yeast enabling efficiently mixing different biosynthetic modules spatially separated in the whole plant. This combinatorial synthesis associating several enzymes from Catharanthus roseus resulted in the conversion of tabersonine in tailor-made MIAs bearing both leaf and root-type decorations
The survey of gender differences in high schools of Palermo
The teacher who is inspired by the principles of personalization will do their best to adjust their methods of teaching to the characteristics of each student. With the expression “personalized education” it is intended that the necessity of educational equality to all students is joined to the attention given to the peculiarity of each and every one of them. In concrete, it means to encourage and carryout activities that take into account all that appears to be more suitable for personalizing rapport, the learning process and sentimental aspects of all the students