Despite well established roles of micro
The volume of industrial lignin is expected to increase with the deployment of biorefineries that convert lignocellulosic biomass to renewable chemicals and fuels. Interest in using lignin for value‐added biomedical applications requires understanding of its effects on mammalian and microbial cells, which has been impaired by the toxicity of the solvents used to solubilize lignin. In this study, lignin is solvated in zwitterionic Good's buffers compatible with culture media. Up to 100 mg lignin can be solvated in 1 ml of 3‐morpholinopropane‐1‐sulfonic acid (MOPS, pH 7.2) within 60 min at room temperature, whereby MOPS acts as a chaotropic agent. The addition of MOPS‐solvated lignin to cultures of
- NSF-PAR ID:
- 10458270
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Journal of Applied Polymer Science
- Volume:
- 137
- Issue:
- 37
- ISSN:
- 0021-8995
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
More Like this
-
Summary RNA s in plant development, few aspects have been addressed to understand their effects in seeds especially on lipid metabolism. In this study, we showed that overexpressing microRNA 167A (miR167OE ) in camelina (Camelina sativa ) under a seed‐specific promoter changed fatty acid composition and increased seed size. Specifically, the miR167OE seeds had a lower α‐linolenic acid with a concomitantly higher linoleic acid content than the wild‐type. This decreased level of fatty acid desaturation corresponded to a decreased transcriptional expression of the camelina fatty acid desaturase3 (Cs ) in developing seeds. MiR167 targeted the transcription factor auxin response factor (CsFAD 3ARF 8) in camelina, as had been reported previously in Arabidopsis. Chromatin immunoprecipitation experiments combined with transcriptome analysis indicated that CsARF 8 bound to promoters of camelina andbZIP 67 genes. These transcription factors directly or through theABI 3ABI 3‐bZIP 12 pathway regulateCs expression and affect α‐linolenic acid accumulation. In addition, to decipher the miR167A‐CsFAD 3ARF 8 mediated transcriptional cascade forCs suppression, transcriptome analysis was conducted to implicate mechanisms that regulate seed size in camelina. Expression levels of many genes were altered in miR167FAD 3OE , including orthologs that have previously been identified to affect seed size in other plants. Most notably, genes for seed coat development such as suberin and lignin biosynthesis were down‐regulated. This study provides valuable insights into the regulatory mechanism of fatty acid metabolism and seed size determination, and suggests possible approaches to improve these important traits in camelina. -
Summary Plant small
RNA s (sRNA s) modulate key physiological mechanisms through post‐transcriptional and transcriptional silencing of gene expression. SmallRNA s fall into two major categories: those are reliant onRNA ‐dependentRNA polymerases ( s) for biogenesis and those that are not. KnownRDR /RDR 12 /6 ‐dependentsRNA s include phased and repeat‐associated short interferingRNA s, while known /RDR 12 /6 ‐independentsRNA s are primarily microRNA s (miRNA ) and other hairpin‐derivedsRNA s. In this study we produced and analyzedsRNA ‐seq libraries fromrdr1 /rdr2 /rdr6 triple mutant plants. We found 58 previously annotated miRNA loci that were reliant on , ‐RDR 12 , or ‐6 function, casting doubt on their classification. We also found 38 /RDR 12 /6‐independentsRNA loci that are not s or otherwise hairpin‐derived, and did not fit into other known paradigms forMIRNA sRNA biogenesis. These 38sRNA ‐producing loci have as‐yet‐undescribed biogenesis mechanisms, and are frequently located in the vicinity of protein‐coding genes. Altogether, our analysis suggests that these 38 loci represent one or more undescribed types ofsRNA inArabidopsis thaliana . -
Abstract The Salicaceae family is of growing interest in the study of dioecy in plants because the sex determination region (SDR) has been shown to be highly dynamic, with differing locations and heterogametic systems between species. Without the ability to transform and regenerate
Salix in tissue culture, previous studies investigating the mechanisms regulating sex in the genusSalix have been limited to genome resequencing and differential gene expression, which are mostly descriptive in nature, and functional validation of candidate sex determination genes has not yet been conducted. Here, we used Arabidopsis to functionally characterize a suite of previously identified candidate genes involved in sex determination and sex dimorphism in the bioenergy shrub willow . Six candidate master regulator genes for sex determination were heterologously expressed in Arabidopsis, followed by floral proteome analysis. In addition, 11 transcription factors with predicted roles in mediating sex dimorphism downstream of the SDR were tested using DAP‐Seq in both male and femaleSalix purpurea DNA. The results of this study provide further evidence to support models for the roles ofS. purpurea ARR17 andGATA15 as master regulator genes of sex determination in , contributing to a regulatory system that is notably different from that of its sister genusS. purpurea Populus . Evidence was also obtained for the roles of two transcription factors, anAP2 /ERF family gene and a homeodomain‐like transcription factor, in downstream regulation of sex dimorphism. -
Summary Many plants require prolonged exposure to cold to acquire the competence to flower. The process by which cold exposure results in competence is known as vernalization. In
Arabidopsis thaliana , vernalization leads to the stable repression of the floral repressor via chromatin modification, including an increase of trimethylation on lysine 27 of histone H3 (H3K27me3) by Polycomb Repressive Complex 2 (FLOWERING LOCUS CPRC 2). Vernalization in pooids is associated with the stable induction of a floral promoter, (VERNALIZATION 1VRN1 ). From a screen for mutants with a reduced vernalization requirement in the model grassBrachypodium distachyon , we identified two recessive alleles of (ENHANCER OF ZESTE ‐LIKE 1 ).EZL 1 is orthologous toEZL 1A. thaliana , a gene that encodes the catalytic subunit ofCURLY LEAF 1PRC 2.B. distachyon ezl1 mutants flower rapidly without vernalization in long‐day (LD ) photoperiods; thus, is required for the proper maintenance of the vegetative state prior to vernalization. Transcriptomic studies inEZL 1ezl1 revealed mis‐regulation of thousands of genes, including ectopic expression of several floral homeotic genes in leaves. Loss of results in the global reduction of H3K27me3 and H3K27me2, consistent with this gene making a major contribution toEZL 1PRC 2 activity inB. distachyon . Furthermore, inezl1 mutants, the flowering genes andVRN 1 (AGAMOUS ) are ectopically expressed and have reduced H3K27me3. Artificial microAG RNA knock‐down of either orVRN 1 inAG ezl1‐1 mutants partially restores wild‐type flowering behavior in non‐vernalized plants, suggesting that ectopic expression inezl1 mutants may contribute to the rapid‐flowering phenotype. -
Summary The collaborative non‐self‐recognition model for S‐
RN ase‐based self‐incompatibility predicts that multiple S‐locus F‐box proteins (SLF s) produced by pollen of a givenS ‐haplotype collectively mediate ubiquitination and degradation of all non‐self S‐RN ases, but not self S‐RN ases, in the pollen tube, thereby resulting in cross‐compatible pollination but self‐incompatible pollination. We had previously used pollen extracts containingGFP ‐fused S2‐SLF 1 (SLF 1 with anS 2‐haplotype) ofPetunia inflata for co‐immunoprecipitation (Co‐IP ) and mass spectrometry (MS ), and identified PiCUL 1‐P (a pollen‐specific Cullin1), PiSSK 1 (a pollen‐specific Skp1‐like protein) and PiRBX 1 (a conventional Rbx1) as components of theSCFS 2–SLF 1complex. Using pollen extracts containing PiSSK 1:FLAG :GFP for Co‐IP /MS , we identified two additionalSLF s (SLF 4 andSLF 13) that were assembled intoSCFSLF complexes. As 17 genes (SLF toSLF 1 ) have been identified inSLF 17S 2andS 3pollen, here we examined whether all 17SLF s are assembled into similar complexes and, if so, whether these complexes are unique toSLF s. We modified the previous Co‐IP /MS procedure, including the addition of style extracts from four differentS ‐genotypes to pollen extracts containing PiSSK 1:FLAG :GFP , to perform four separate experiments. The results taken together show that all 17SLF s and anSLF ‐like protein,SLFL ike1 (encoded by anS ‐locus‐linked gene), co‐immunoprecipitated with PiSSK 1:FLAG :GFP . Moreover, of the 179 other F‐box proteins predicted byS 2andS 3pollen transcriptomes, only a pair with 94.9% identity and another pair with 99.7% identity co‐immunoprecipitated with PiSSK 1:FLAG :GFP . These results suggest thatSCFSLF complexes have evolved specifically to function in self‐incompatibility.