In silico promoter analysis and expression of the BIG BROTHER gene in different organs of potato

The ubiquitin E3 ligase BIG BROTHER/ENHANCER OF DA1 (BB) gene encoding a RING finger protein was identified as a central growth regulator in Arabidopsis thaliana. It was found that BB restricts cell proliferation and promotes leaf senescence. Besides of Arabidopsis, however, the role and regulation of BB in other plant species is only sparsely known. Supposing that the BB gene, like in Arabidopsis, has an important role in the development of potato we aimed to analyse a 3.0-kb promoter sequence of the potato BB gene, StBB, in silico and study the level of StBB expression by quantitative reverse transcription PCR in different organs. A total of 48 binding sites for 15 transcription factor (TF) families were predicted. Most of them were located in the -1.5-kb promoter region. The dominating family of TFs was DOF. It was found that 20 out of the 24 TFs with known functions are involved in developmental processes such as for example, the flower-, leaf-, stem- and root development or cell cycle regulation. In line with this finding, the StBB mRNA was detected in each organ tested with the largest amounts in petal and stamen. These results suggest a similar function of StBB in potato than that is of BB in Arabidopsis, i.e., restriction of organ overgrowth during development and limitation of the plant growth

Metabolite analysis of tubers and leaves of two potato cultivars and their grafts.

Grafting experiments have shown that photoperiod-dependent induction of tuberisation in potato (Solanum tuberosum L.) is controlled by multiple overlapping signals, including mobile proteins, mRNAs, miRNAs and phytohormones. The effect of vegetative organs and tubers at metabolite level and vice versa, however, has not been studied in detail in potato. To unravel the influence of vegetative organs on the primary polar metabolite content of potato tubers and the effect of tuberisation on the metabolite content of leaves grafting experiments were carried out. Two potato cultivars, Hópehely (HP) and White Lady (WL), were homo- and hetero-grafted, and the effects of grafting were investigated in comparison to non-grafted controls. Non-targeted metabolite analysis using gas chromatography-mass spectrometry showed that the major difference between HP and WL tubers is in sucrose concentration. The sucrose level was higher in HP than in WL tubers and was not changed by grafting, suggesting that the sucrose concentration of tubers is genetically determined. The galactinol level was 8-fold higher in the WL leaves than in the HP leaves and, unlike the sucrose concentration of tubers, was altered by grafting. A positive correlation between the growth rate of the leaves and the time of tuber initiation was detected. The time of tuber initiation was delayed in the WL rootstocks by HP scions and shortened in the HP rootstocks by WL scions, supporting the previous finding that tuberisation is triggered by source-derived mobile signals

Metabolite Profiling of In Vitro Cultured and Field Grown Rhizomes of Acorus calamus from Mongolia Using GC-MS

Acorus calamus (sweet flag) is used in the traditional Chinese and Indian medicines for various ailments. Due to its extensive use in herbal medicine, natural resources from the world's forests are being depleted at an alarming rate. In the present study, an in vitro cell culture technique is being explored as an alternative to field grown A. calamus with respect to the metabolite profile, antioxidant properties, total phenol, and total flavonoid content. Gas chromatography mass spectrometry (GC-MS) was utilized to compare the metabolite profiling between methanolic extracts of in vitro and field grown rhizome tissues of A. calamus. A statistical analysis indicated an upregulation of a-selinene, which is representative of sesquiterpene ketones, and a cyclic polyol, D-pinitol, which has an insulin mimicking effect in the in vitro cultivated rhizome tissue when compared to field grown rhizomes. Significantly higher free-radical scavenging activity (IC50 69.32 mu g mL(-1)), total phenolic content (71.60 mg GAE g(-1)), and total flavonoid content (42.34 mg CE g(-1)) were observed in in vitro rhizome tissues compared with those from field grown rhizomes. These observations suggest that the in vitro cultivation of Acorus rhizomes could be exploited as an alternative to field grown A. calamus, as it is an endangered medicinal plant. The production of useful metabolites by the in vitro cultured rhizomes can be explored successfully for utilization by various food and drug industries