The transActing siRNA Pathway

The tasiRNA class of endogenous sRNAs are generated via an overlapping, yet distinct silencing pathway from the miRNA biogenesis pathway. In plants, two miRNAs, miR173 and miR390, have been shown to induce an additional level of complexity to the control of gene expression for normal development (Axtell et al. 2007). These two miRNAs target five tasiRNA transcripts (TAS) in a DCL1 HYL1-mediated process to initiate the 21-nt phasing of tasiRNA production. However, instead of being identified for...

Biosynthesis of Monoterpene Indole Alkaloids MIA

The approximately 2,000 MIA chemical structures described so far are widespread in a large number of plant species (Ziegler and Facchini 2008). Some of these molecules are of interest to human health, such as the anticancer drugs vinblastine and vincristine and the antihypertensive drug ajmalicine specifically produced in Catharanthus roseus, the anti-arrythmic ajmaline produced in Rauvolfia serpentina, or the anticancer compound camptothecin produced mostly in Camptotheca acuminata (Fig. 8.1,...

Two Component Transactivated Gene Switches Promising Systems for Flexible Transgene Expression

Two-component gene switches are ideal molecular systems to achieve tightly regulated transgene expression in a tissue-specific mode and or in response to a specific inducer. Generally, the two-component transactivation system comprises two transcriptional units, namely the TF expressed by a strong constitutive or tissue-specific promoter, and the inducible (target) regulatory unit consisting of a minimal promoter region and multimeric upstream c s-motif-repeats specific for binding to the TF...

Health Benefits of Carotenoid Derived Vitamins and Nutrients

Plants and microorganisms provide a primary natural source of essential vitamins for human diets. These micronutrients are necessary for human health and development. There has been a quest over the last decade to discover genes and biochemical processes which control an individual plant's production of these health-promoting micronutrients. They are generally classified into fat and water soluble vitamins, depending on their biochemical properties. The group of fat soluble vitamins consists of...

References

Alper H, Fischer C, Nevoigt E, Stephanopoulos G 2005 Tuning genetic control through promoter engineering. Proc Natl Acad Sci USA 102 12678-12683 Amirsadeghi S, McDonald AE, Vanlerberghe GC 2007 A glucocorticoid-inducible gene expression system can cause growth defects in tobacco. Planta 226 453-463 An G, Costa MA, Ha SB 1990 Nopaline synthase promoter is wound inducible and auxin inducible. Plant Cell 2 225-233 Andersen SU, Cvitanich C, Hougaard BK, Roussis A, Gr0nlund M, Jensen DB, Fr0kjaer...