Profiling of oligolignols reveals monolignol coupling conditions in lignifying poplar xylem

Lignin is an aromatic heteropolymer, abundantly present in the walls of secondary thickened cells. Although much research has been devoted to the structure and composition of the polymer to obtain insight into lignin polymerization, the low-molecular weight oligolignol fraction has escaped a detailed characterization. This fraction, in contrast to the rather inaccessible polymer, is a simple and accessible model that reveals details about the coupling of monolignols, an issue that has raised considerable controversy over the past years. We have profiled the methanol-soluble oligolignol fraction of poplar (Populus spp.) xylem, a tissue with extensive lignification. Using liquid chromatography-mass spectrometry, chemical synthesis, and nuclear magnetic resonance, we have elucidated the structures of 38 compounds, most of which were dimers, trimers, and tetramers derived from coniferyl alcohol, sinapyl alcohol, their aldehyde analogs, or vanillin. All structures support the recently challenged random chemical coupling hypothesis for lignin polymerization. Importantly, the structures of two oligomers, each containing a γ-p-hydroxybenzoylated syringyl unit, strongly suggest that sinapyl p-hydroxybenzoate is an authentic precursor for lignin polymerization in poplar

Fungal Endophytes of Populus trichocarpa Alter Host Phenotype, Gene Expression, and Rhizobiome Composition.

Mortierella and Ilyonectria genera include common species of soil fungi that are frequently detected as root endophytes in many plants, including Populus spp. However, the ecological roles of these and other endophytic fungi with respect to plant growth and function are still not well understood. The functional ecology of two key taxa from the P. trichocarpa rhizobiome, M. elongata PMI93 and I. europaea PMI82, was studied by coupling forest soil bioassays with environmental metatranscriptomics. Using soil bioassay experiments amended with fungal inoculants, M. elongata was observed to promote the growth of P. trichocarpa. This response was cultivar independent. In contrast, I. europaea had no visible effect on P. trichocarpa growth. Metatranscriptomic studies revealed that these fungi impacted rhizophytic and endophytic activities in P. trichocarpa and induced shifts in soil and root microbial communities. Differential expression of core genes in P. trichocarpa roots was observed in response to both fungal species. Expression of P. trichocarpa genes for lipid signaling and nutrient uptake were upregulated, and expression of genes associated with gibberellin signaling were altered in plants inoculated with M. elongata, but not I. europaea. Upregulation of genes for growth promotion, downregulation of genes for several leucine-rich repeat receptor kinases, and alteration of expression of genes associated with plant defense responses (e.g., jasmonic acid, salicylic acid, and ethylene signal pathways) also suggest that M. elongata manipulates plant defenses while promoting plant growth

Three-steps in one-pot: whole-cell biocatalytic synthesis of enantiopure (+)- and (−)-pinoresinol via kinetic resolution

Additional file 5. HPLC chromatograms of enantiomeric separations of reaction products. a Application of AtPrR2; b application of FiPLR. [3a] = (+)-pinoresinol 3a, [3b] = (−)-pinoresinol 3b, [4a] = (+)-lariciresinol 4a, [4b] = (−)-lariciresinol 4b, [5a] = (−)-secoisolariciresinol 5a

MpTCP1 controls cell proliferation and redox processes in Marchantia polymorpha

TCP transcription factors are key regulators of angiosperm cell proliferation processes. It is unknown whether their regulatory growth capacities are conserved across land plants, which we examined in liverworts, one of the earliest diverging land plant lineages. We generated knockout mutants for MpTCP1, the single TCP‐P clade gene in Marchantia polymorpha, and characterized its function conducting cell proliferation and morphological analyses as well as mRNA expression, transcriptome, chemical and DNA binding studies. Mptcp1ge lines show a reduced vegetative thallus growth and extra tissue formation in female reproductive structures. Additionally, mutant plants reveal increased H2O2 levels and an enhanced pigmentation in the thallus caused by formation of secondary metabolites, such as aminochromes. MpTCP1 proteins interact redox‐dependently with DNA and regulate the expression of a comprehensive redox network, comprising enzymes involved in H2O2 metabolism. MpTCP1 regulates Marchantia growth context‐dependently. Redox sensitivity of the DNA binding capacity of MpTCP1 proteins provides a mechanism to respond to altered redox conditions. Our data suggest that MpTCP1 activity could thereby have contributed to diversification of land plant morphologies and to adaptations to abiotic and biotic challenges, experienced by liverworts during early land plant colonization

Pemetaan, Karakterisasi, Dan Pengembangan Primer-primer Lokus Pup1 (P Uptake 1) Pada Padi Untuk Peningkatan Toleransi Terhadap Defisiensi Fosfor

Phosphorus (P) is the second most important nutrient forplants after nitrogen, but is available in very low amount. Pdeficiency in rice would reduce the number of tillers andgrain production. There are numerous publications onexploration of genes that are associated with P. Manyresearches on P that are directed to breeding program andinvolving many countries/institutions focus on Pup1research. Pup1 (P uptake 1) is associated with P uptake hasbeen well mapped on chromosome 12 at a distance of 15.31to 15.47 Mb and microsatellite markers between RM28073and RM28102 can be used as a selection tool in the MAB(Marker Assisted Backrossing) program. Indonesia is veryconcerned with this research because of P-deficientproblem. This review aims to provide current information ofresearch that explore the genes in Pup1 locus. This reviewoutlines the history of Pup1 mapping, to explain sequenceand expression analysis of Pup1, and to inform of Pup1specific primers. The latest information is expected to beuseful for rice breeders in Indonesia, especially for thosewho are interested to P deficiency research. Study of geneswithin Pup1 locus is still ongoing, and found that somegenes do not contribute directly to P uptake. This mayindicate that Pup1 locus use other mechanisms in the Puptake. This may indicate that some genes (dirigent-like,fatty acid α-dioxygenase, aspartic proteinases) play a role inthe increasing level of lignin in P deficient condition.Increasing level of lignin would increase the volume of rootsand thus increasing P uptake and resistance to biotic andabiotic stresses. Specific markers to detect the genes in thePup1 locus have been successfully developed, and can beused for breeding and exploration activities on Indonesianrice germplasm

Phytoestrogens

Collectively, plants contain several different families of natural products among which are compounds with weak estrogenic or antiestrogenic activity toward mammals. These compounds, termed phytoestrogens, include certain isoflavonoids, flavonoids, stilbenes, and lignans. The best-studied dietary phytoestrogens are the soy isoflavones and the flaxseed lignans. Their perceived health beneficial properties extend beyond hormone-dependent breast and prostate cancers and osteoporosis to include cognitive function, cardiovascular disease, immunity and inflammation, and reproduction and fertility. In the future, metabolic engineering of plants could generate novel and exquisitely controlled dietary sources with which to better assess the potential health beneficial effects of phytoestrogens

The phenolic complex in flaxseed

Flaxseed is the richest plant source of the lignan secoisolariciresinol diglucoside (SDG). In flaxseed, SDG exists in an oligomeric structure with 3-hydroxy-3-methyl glutaric acid (HMGA) forming a phenolic complex together with p-coumaric acid and ferulic acid glucosides and herbacetin diglucoside (HDG). Epidemiological and animal studies indicate protective effects of flaxseed and SDG towards hormone-dependent cancers and cardiovascular diseases, and reducing effect toward cholesterol levels in blood. Knowledge about the structural features and properties of the phenolic complex are required to further understand bioavailability, bioconversion and bioactivity of flaxseed lignans in humans and animals, the biosynthesis in flaxseed, as well as if it may affect technology and quality of food products containing flaxseed or the phenolic complex. A new fast and simple high-performance liquid chromatographic (HPLC) method was developed for analysing secoisolariciresinol diglucoside (SDG), p-coumaric acid glucoside and ferulic acid glucoside, based on direct hydrolysis of defatted flaxseed flour using alkali. Variations in SDG, p-coumaric acid glucoside and ferulic acid glucoside content were reported in flaxseed samples and bread products containing flaxseed. The composition and properties of flaxseed phenolic complex were studied by reversed-phase liquid chromatography and gel filtration fractionation. Results indicate that the phenolic glucosides exist in oligomers with variable molecular sizes. A complicated linkage pattern and/or possibly interactions with other components may contribute to the observed complexity. SDG and the phenolic complex showed similar hydrogen-donating abilities to ferulic acid but higher than α-tocopherol in the DPPH inhibition metod, suggesting that SDG was the only active antioxidant in the phenolic complex. Contradicting results were obtained on the effect of SDG on levels of Vitamin E and cholesterol in two rat studies

Altered gene expression by sedaxane increases PSII efficiency, photosynthesis and growth and improves tolerance to drought in wheat seedlings

Succinate dehydrogenase inhibitor (SDHI) fungicides have been shown to increase PSII efficiency and photosynthesis under drought stress in the absence of disease to enhance the biomass and yield of winter wheat. However, the molecular mechanism of improved photosynthetic efficiency observed in SDHI-treated wheat has not been previously elucidated. Here we used a combination of chlorophyll fluorescence, gas exchange and gene expression analysis, to aid our understanding of the basis of the physiological responses of wheat seedlings under drought conditions to sedaxane, a novel SDHI seed treatment. We show that sedaxane increased the efficiency of PSII photochemistry, reduced non-photochemical quenching and improved the photosynthesis and biomass in wheat correlating with systemic changes in the expression of genes involved in defense, chlorophyll synthesis and cell wall modification. We applied a coexpression network-based approach using differentially expressed genes of leaves, roots and pregerminated seeds from our wheat array datasets to identify the most important hub genes, with top ranked correlation (higher gene association value and z-score) involved in cell wall expansion and strengthening, wax and pigment biosynthesis and defense. The results indicate that sedaxane confers tolerant responses of wheat plants grown under drought conditions by redirecting metabolites from defense/stress responses towards growth and adaptive development

Ketahanan Galur-Galur Padi Pup1 Terhadap Penyakit Blas

Blast is one of major disease on the upland rice in Indonesia. Upland rice lines derived from Kasalath and NILC443 crosses, containing Pup1 gen locus had been developed and evaluated for P fertilizer efficiency. Those lines would be evaluated for blast resistance, due to the fact that Pup1 locus contains genes involved in plant defend mechanism to disease, including blast disease. The BC2F5 plants derived from six crosses (DK, DN, SK, SN, BK, BN) were used in this research. Responses to blast disease in the green house were evaluated at ICABIOGRAD Bogor from March to April 2011, using combination of three blast races (race 173, 033, and 133). The response to blast disease in the field was evaluated at Taman Bogo Research Station, Lampung, and at farmer\u27s field in Cikeusal Village, Banten, from January to April 2011. Molecular analysis to trace Pup1 gene locus was conducted at the Molecular Biology Laboratory, using specific primer K20-2, from January to August 2013. Based on the molecular analysis all Pup1 lines showed homozygoes alleles, except the heterozygoes alleles on SK7, SK8, SK15, SK16, BN8 line, which were then not included in the next planting. The responses to blast at greenhouse among lines varied, but the Pup1 lines were mostly at level of moderate resistan (AT). Based on the result from the field experiment, most of Pup1 lines were resistance, however the susceptible check plant (Kencana Bali) did not show blast fungus infection. Differences of the result might be due to the blast testing at the green house which was more favorable for blast fungal growth. The effect of Pup1 gene locus showed clearly on resistance of plants obtained from Situ Bagendit cross, where Situ Bagendit was susceptible and does not contain the Pup1 locus. Additional of Pup1 locus in Situ Bagendit genome had increased the degree of resistant to blast