Jan G. Jaworski

Interest in the Shroud of Turin, a canvas with an image of a man's body, seen from the front and back, with traces of torture similar to that inflicted on Jesus and described in the Gospels of the New Testament, has also found a place in world science since the 20th century. Especially after the words of Pope John Paul II in the Turin Cathedral, where the Shroud is kept. Faced with the dilemma of whether we are dealing with the burial shroud of Jesus or a medieval forgery, so ingenious that the science of the 21st century is unable to either falsify or confirm this thesis, the Pope decided that resolving this issue was not "in the Church's special competence". On the other hand, it can be undertaken by scientists, because "it is not a matter of faith", but should become the subject of studies undertaken "without prejudice that would lead to false results; (...) to act with inner freedom and caring respect, both from the point of view of scientific methodology and the sensitivity of believers. " The prepared lexicon has the ambition to present the history of syndonological research to date and to become an element of a scientific workshop that helps to get acquainted with reliable research results and to serve as a standard reference work for further research projects of a monographic nature.

Acyl-ACPs that enable fatty acid biosynthesis were uniquely profiled and quantified, resulting in discovery of novel ACP products with unknown function and prov

Acyl carrier proteins (ACPs) are the scaffolds for fatty acid biosynthesis in living systems, rendering them essential to a comprehensive understanding of lipid metabolism; however, accurate quantitative methods to assess individual acyl-ACPs do not exist. A robust method was developed to quantify acyl-ACPs at picogram levels. Acyl-ACP elongation intermediates (3-hydroxyacyl-ACPs and 2, 3- trans -enoyl-ACPs), and unexpected medium chain (C10:1, C14:1) and polyunsaturated long chain acyl-ACPs (C16:3) were also identified, indicating the sensitivity of the method and that descriptions of lipid metabolism and ACP function are incomplete. Such ACPs are likely important to medium chain lipid production for fuels and highlight poorly understood lipid remodeling events in the chloroplast. The approach is broadly applicable to Type II FAS systems found in plants, bacteria, and mitochondria of animal and fungal systems because it uses a strategy that capitalizes on a highly conserved Asp-Ser-Leu-Asp (DSLD) amino acid sequence in ACPs to which acyl groups are attached. This allows for sensitive quantification using LC-MS/MS with de novo generated standards and an isotopic dilution strategy and will fill a gap in understanding, providing insights through quantitative exploration of fatty acid biosynthesis processes for optimal biofuels, renewable feed stocks, and medical studies in health and disease.

Summary: Camelina (Camelina sativa), a Brassicaceae oilseed, has received recent interest as a biofuel crop and production platform for industrial oils. Limiting wider production of camelina for these uses is the need to improve the quality and content of the seed protein‐rich meal and oil, which is enriched in oxidatively unstable polyunsaturated fatty acids that are deleterious for biodiesel. To identify candidate genes for meal and oil quality improvement, a transcriptome reference was built from 2047 Sanger ESTs and more than 2 million 454‐derived sequence reads, representing genes expressed in developing camelina seeds. The transcriptome of approximately 60K transcripts from 22 597 putative genes includes camelina homologues of nearly all known seed‐expressed genes, suggesting a high level of completeness and usefulness of the reference. These sequences included candidates for 12S (cruciferins) and 2S (napins) seed storage proteins (SSPs) and nearly all known lipid genes, which have been compiled into an accessible database. To demonstrate the utility of the transcriptome for seed quality modification, seed‐specific RNAi lines deficient in napins were generated by targeting 2S SSP genes, and high oleic acid oil lines were obtained by targeting FATTY ACID DESATURASE 2 (FAD2) and FATTY ACID ELONGASE 1 (FAE1). The high sequence identity between Arabidopsis thaliana and camelina genes was also exploited to engineer high oleic lines by RNAi with Arabidopsis FAD2 and FAE1 sequences. It is expected that these transcriptomic data will be useful for breeding and engineering of additional camelina seed traits and for translating findings from the model Arabidopsis to an oilseed crop.

The release of fatty acids from membrane lipids has been implicated in various metabolic and physiological processes, but in many cases, the enzymes involved and their functions in plants remain unclear. Patatin-related phospholipase As (pPLAs) constitute a major family of acyl-hydrolyzing enzymes in plants. Here, we show that pPLAIIIδ promotes the production of triacylglycerols with 20- and 22-carbon fatty acids in Arabidopsis (Arabidopsis thaliana). Of the four pPLAIIIs (α, β, γ, δ), only pPLAIIIδ gene knockout results in a decrease in seed oil content, and pPLAIIIδ is most highly expressed in developing embryos. The overexpression of pPLAIIIδ increases the content of triacylglycerol and 20- and 22-carbon fatty acids in seeds with a corresponding decrease in 18-carbon fatty acids. Several genes in the glycerolipid biosynthetic pathways are up-regulated in pPLAIIIδ-overexpressing siliques. pPLAIIIδ hydrolyzes phosphatidylcholine and also acyl-coenzyme A to release fatty acids. pPLAIIIδ-overexpressing plants have a lower level, whereas pPLAIIIδ knockout plants have a higher level, of acyl-coenzyme A than the wild type. Whereas seed yield decreases in transgenic plants that ubiquitously overexpress pPLAIIIδ, seed-specific overexpression of pPLAIIIδ increases seed oil content without any detrimental effect on overall seed yield. These results indicate that pPLAIIIδ-mediated phospholipid turnover plays a role in fatty acid remodeling and glycerolipid production.

Sphingolipid synthesis is initiated by condensation of Ser with palmitoyl-CoA producing 3-ketodihydrosphinganine (3-KDS), which is reduced by a 3-KDS reductase to dihydrosphinganine. Ser palmitoyltransferase is essential for plant viability. Arabidopsis thaliana contains two genes (At3g06060/TSC10A and At5g19200/TSC10B) encoding proteins with significant similarity to the yeast 3-KDS reductase, Tsc10p. Heterologous expression in yeast of either Arabidopsis gene restored 3-KDS reductase activity to the yeast tsc10Δ mutant, confirming both as bona fide 3-KDS reductase genes. Consistent with sphingolipids having essential functions in plants, double mutant progeny lacking both genes were not recovered from crosses of single tsc10A and tsc10B mutants. Although the 3-KDS reductase genes are functionally redundant and ubiquitously expressed in Arabidopsis, 3-KDS reductase activity was reduced to 10% of wild-type levels in the loss-of-function tsc10a mutant, leading to an altered sphingolipid profile. This perturbation of sphingolipid biosynthesis in the Arabidopsis tsc10a mutant leads an altered leaf ionome, including increases in Na, K, and Rb and decreases in Mg, Ca, Fe, and Mo. Reciprocal grafting revealed that these changes in the leaf ionome are driven by the root and are associated with increases in root suberin and alterations in Fe homeostasis.

Sphingolipids are structural components of endomembranes and function through their metabolites as bioactive regulators of cellular processes such as programmed cell death. A characteristic feature of plant sphingolipids is their high content of trihydroxy long-chain bases (LCBs) that are produced by the LCB C-4 hydroxylase. To determine the functional significance of trihydroxy LCBs in plants, T-DNA double mutants and RNA interference suppression lines were generated for the two Arabidopsis thaliana LCB C-4 hydroxylase genes Sphingoid Base Hydroxylase1 (SBH1) and SBH2. These plants displayed reductions in growth that were dependent on the content of trihydroxy LCBs in sphingolipids. Double sbh1 sbh2 mutants, which completely lacked trihydroxy LCBs, were severely dwarfed, did not progress from vegetative to reproductive growth, and had enhanced expression of programmed cell death associated–genes. Furthermore, the total content of sphingolipids on a dry weight basis increased as the relative amounts of trihydroxy LCBs decreased. In trihydroxy LCB–null mutants, sphingolipid content was ∼2.5-fold higher than that in wild-type plants. Increases in sphingolipid content resulted from the accumulation of molecular species with C16 fatty acids rather than with very-long-chain fatty acids, which are more commonly enriched in plant sphingolipids, and were accompanied by decreases in amounts of C16-containing species of chloroplast lipids. Overall, these results indicate that trihydroxy LCB synthesis plays a central role in maintaining growth and mediating the total content and fatty acid composition of sphingolipids in plants.