Effective binuclear Pd(II) complexes for Suzuki reactions in water

A series of new ionic binuclear Pd(II) complexes supported by water-soluble bis(?-diimine) ligands were prepared and employed as catalysts for the palladium-catalyzed Suzuki reaction in aqueous media. The binuclear nature of the complexes increased the reaction rate, while electronic and steric modification of the ligand frameworks had a remarkable influence upon the catalytic activity of the palladium complexes. The catalysts were shown to be homogeneous through mercury poisoning experiments and complexes could be recycled more than 10 times without loss of catalytic activity. Copyright © 2013 John Wiley & Sons, Ltd

A chromosome-scale genome assembly of Castanopsis hystrix provides new insights into the evolution and adaptation of Fagaceae species

Fagaceae species dominate forests and shrublands throughout the Northern Hemisphere, and have been used as models to investigate the processes and mechanisms of adaptation and speciation. Compared with the well-studied genus Quercus, genomic data is limited for the tropical-subtropical genus Castanopsis. Castanopsis hystrix is an ecologically and economically valuable species with a wide distribution in the evergreen broad-leaved forests of tropical-subtropical Asia. Here, we present a high-quality chromosome-scale reference genome of C. hystrix, obtained using a combination of Illumina and PacBio HiFi reads with Hi-C technology. The assembled genome size is 882.6 Mb with a contig N50 of 40.9 Mb and a BUSCO estimate of 99.5%, which are higher than those of recently published Fagaceae species. Genome annotation identified 37,750 protein-coding genes, of which 97.91% were functionally annotated. Repeat sequences constituted 50.95% of the genome and LTRs were the most abundant repetitive elements. Comparative genomic analysis revealed high genome synteny between C. hystrix and other Fagaceae species, despite the long divergence time between them. Considerable gene family expansion and contraction were detected in Castanopsis species. These expanded genes were involved in multiple important biological processes and molecular functions, which may have contributed to the adaptation of the genus to a tropical-subtropical climate. In summary, the genome assembly of C. hystrix provides important genomic resources for Fagaceae genomic research communities, and improves understanding of the adaptation and evolution of forest trees

Influence of the light harvesting proteins Lhbc3 and Lhbc5 on photosynthesis of plants lacking Lhbc1 and Lhbc2.

Photosynthesis is one of the most important biological processes on earth, producing carbohydrates and oxygen. The light is captured with the aid of light harvesting proteins. Light harvesting complex proteins in PSII are important both in light absorption and dynamic regulation. This study aims to confirm the individual role of Lhcb1 and Lhcb2 in the regulation of photosynthesis based on the KO lines: koLhcb3, koLhcb5 and koLhcb3koLhcb5. By the tool of western blot, phosphorylation analysis, state transition and non-photochemical quenching, the results indicated that the knock-out of Lhcb3, Lhcb5 or both of them did not cause additional effect on amiLhcb1 and amiLhcb2 single mutants, and then the role of Lhcb1and Lhcb2 has been complement and confirmed

Complete chloroplast genome sequence of the Mongolian oak, Quercus mongolica (Fagaceae)

Quercus mongolica is a major tree species in East Asian hardwood forests. In this study, we assembled a complete chloroplast (cp) genome of Q. mongolica based on next-generation sequencing data. The cp genome was 161,295 bp, with a large single-copy region (90,583 bp), a small single-copy region (19,060 bp), and two short inverted repeat regions (25,826bp). The genome contains 121 genes, including 85 protein-coding genes, eight rRNA genes, and 29 tRNA genes. Phylogenetic analyses based on cp genome sequences revealed that Q. mongolica was grouped with species from section Quercus

Microhomologies Are Associated with Tandem Duplications and Structural Variation in Plant Mitochondrial Genomes

Short tandem repeats (STRs) contribute to structural variation in plant mitochondrial genomes, but the mechanisms underlying their formation and expansion are unclear. In this study, we detected high polymorphism in the nad7-1 region of the Pinus tabuliformis mitogenome caused by the rapid accumulation of STRs and rearrangements over a few million years ago. The STRs in nad7-1 have a 7-bp microhomology (TAG7) flanking the repeat array. We then scanned the mitogenomes of 136 seed plants to understand the role of microhomology in the formation of STR and mitogenome evolution. A total of 13,170 STRs were identified, and almost half of them were associated with microhomologies. A substantial amount (1,197) of microhomologies was long enough to mediate structural variation, and the length of microhomology is positively correlated with the length of tandem repeat unit. These results suggest that microhomology may be involved in the formation of tandem repeat via microhomology-mediated pathway, and the formation of longer duplicates required greater length of microhomology. We examined the abundance of these 1,197 microhomologies, and found 75% of them were enriched in the plant mitogenomes. Further analyses of the 400 prevalent microhomologies revealed that 175 of them showed differential enrichment between angiosperms and gymnosperms and 186 differed between angiosperms and conifers, indicating lineage-specific usage and expansion of microhomologies. Our study sheds light on the sources of structural variation in plant mitochondrial genomes and highlights the importance of microhomology in mitochondrial genome evolution

Morning glory species co-occurrence is associated with asymmetrically decreased and cascading reproductive isolation.

Hybridization between species can affect the strength of the reproductive barriers that separate those species. Two extensions of this effect are (1) the expectation that asymmetric hybridization or gene flow will have asymmetric effects on reproductive barrier strength and (2) the expectation that local hybridization will affect only local reproductive barrier strength and could therefore alter within-species compatibility. We tested these hypotheses in a pair of morning glory species that exhibit asymmetric gene flow from highly selfing Ipomoea lacunosa into mixed-mating Ipomoea cordatotriloba in regions where they co-occur. Because of the direction of this gene flow, we predicted that reproductive barrier strength would be more strongly affected in I. cordatotriloba than I. lacunosa. We also predicted that changes to reproductive barriers in sympatric I. cordatotriloba populations would affect compatibility with allopatric populations of that species. We tested these predictions by measuring the strength of a reproductive barrier to seed set across the species' ranges. Consistent with our first prediction, we found that sympatric and allopatric I. lacunosa produce the same number of seeds in crosses with I. cordatotriloba, whereas crosses between sympatric I. cordatotriloba and I. lacunosa are more successful than crosses between allopatric I. cordatotriloba and I. lacunosa. This difference in compatibility appears to reflect an asymmetric decrease in the strength of the barrier to seed set in sympatric I. cordatotriloba, which could be caused by I. lacunosa alleles that have introgressed into I. cordatotriloba. We further demonstrated that changes to sympatric I. cordatotriloba have decreased its ability to produce seeds with allopatric populations of the same species, in line with our second prediction. Thus, in a manner analogous to cascade reinforcement, we suggest that introgression associated with hybridization not only influences between-species isolation but can also contribute to isolation within a species

Complete chloroplast genome sequence of a Chinese traditional cultivar in Chrysanthemum, Chrysanthemum morifolium ‘Anhuishiliuye’

The complete plastid genome of Chrysanthemum morifolium ‘Anhuishiliuye’, a Chinese traditional cultivar, was determined and analyzed in this work. It had a circular-mapping molecular with the length of 151,059 bp.The LSC and SSC of 82,857 bp and 18,294 bp were separated by two IRs of 24,954 bp. The chloroplast genome of C. morifolium ‘Anhuishiliuye’ contains 125 genes, including 83 protein-coding genes, 34 ribosomal RNA genes and 8 transfer RNA genes. Phylogenetic analysis showed that C. morifolium ‘Anhuishiliuye’ clustered together with other Chrysanthemum species. The data provided would be useful for elucidation of phylogenetics and evolution in Chrysanthemum cultivars

Nitrogen application save phosphorus deficiency in maize inbred line QXH0121

Nitrogen and phosphorus dual stress significantly inhibited the maize growth and decreased the accumulation of nitrogen and phosphorus in plants. The co-application of nitrogen and phosphorus most significantly increased the biomass compared to the dual deficiency stress, and to our surprise, the repair effect of nitrogen application alone was basically similar to the repair effect of simultaneous application of nitrogen and phosphorus reflected in biomass as well as nitrogen and phosphorus content. Transcriptomic analysis showed that DEGs related to phosphorus transporters in N versus NP group and N versus P group were all up-regulated. These all confirm that the nitrogen application alone mitigated damages caused by low nitrogen and phosphorus dual stress comparable to that of nitrogen and phosphorus co-application. These indicate that the presence of nitrogen is conducive to the accumulation and transportation of phosphorus

Complete chloroplast genome sequence of a Dutch cultivar of Chrysanthemum, Chrysanthemum morifolium ‘Orizaba’ (Asteraceae)

The complete plastid genome of Chrysanthemum morifolium ‘Orizaba’, a cultivar from Holland, was determined and analyzed in this work. It is a circular chromosome and has a length of 151,060 bp. The LSC and SSC of 82,858 bp and 18,294 bp were separated by two IRs of 24,954 bp. The chloroplast genome of C. morifolium ‘Orizaba’ contains 125 genes, including 83 protein-coding genes, eight ribosomal RNA genes, and 34 transfer RNA genes. Phylogenetic analysis showed that C. morifolium ‘Orizaba’ clustered together with other Chrysanthemum varieties in the family Asteraceae. The plastome is useful for the elucidation of phylogenetics and evolution in the Asteraceae and Chrysanthemum varieties

The Maternal Donor of Chrysanthemum Cultivars Revealed by Comparative Analysis of the Chloroplast Genome.

Chrysanthemum (Chrysanthemum morifolium Ramat) is an important floricultural crop and medicinal herb. Modern chrysanthemum cultivars have complex genetic backgrounds because of multiple cycles of hybridization, polyploidization, and prolonged cultivation. Understanding the genetic background and hybrid origin of modern chrysanthemum cultivars can provide pivotal information for chrysanthemum genetic improvement and breeding. By now, the origin of cultivated chrysanthemums remains unclear. In this study, 36 common chrysanthemum cultivars from across the world and multiple wild relatives were studied to identify the maternal donor of modern chrysanthemum. Chloroplast (cp) genomes of chrysanthemum cultivars were assembled and compared with those of the wild relatives. The structure of cp genomes was highly conserved among cultivars and wild relatives. Phylogenetic analyses based on the assembled cp genomes showed that all chrysanthemum cultivars grouped together and shared 64 substitutions that were distinct from those of their wild relatives. These results indicated that a diverged lineage of the genus Chrysanthemum, which was most likely an extinct or un-sampled species/population, provided a maternal source for modern cultivars. These findings provide important insights into the origin of chrysanthemum cultivars, and a source of valuable genetic markers for chrysanthemum breeding programs