The chemical fixation of CO2 into value-added products has recently received much attention. One of the most well-known methods is the coupling of CO2 with epoxides to form cyclic carbonates. Although this field has progressed considerably, it is still a challenge to perform the reaction with atmospheric CO2 or flue gas. Herein we described the development of 4-(dimethylamino)­pyridine hydrobromide ([DMAPH]­Br) as a highly efficient and recyclable catalyst for the formation of cyclic carbonates from atmospheric CO2 and epoxides. In the presence of 1 mol % of [DMAPH]­Br, excellent conversions and selectivities for a broad range of terminal epoxides were achieved under solvent-free conditions. Furthermore, the catalyst could be recycled over five times without appreciable loss of catalytic activity. The excellent catalytic performance of [DMAPH]Br is attributed to the enhanced synergistic interplay of acidic proton and bromide to epoxides and CO2 through positive charge delocalization on its cation.

Abiotic stresses, such as salinity, greatly threaten the growth and productivity of plants. Rice (Oryza sativa L.) is one of the most important food crops, as well as a monocot model for genomic research. To obtain a global view of the molecular response to salinity stress, we conducted a leaf transcriptome analysis on rice seedlings. Two cultivars of rice subspecies indica, including the salt-tolerant genotype Xian156 and the salt-sensitive genotype IR28, were used in the present study. Eighteen RNA libraries were obtained from these two genotypes at three timepoints (0 h, 48 h and 72 h) after applying salinity stress. We obtained the reference-guided assembly of the rice transcriptome, which resulted in 1,375 novel genes, including 1,371 annotated genes. A comparative analysis between genotypes and time points showed 5,273 differentially expressed genes (DEGs), of which 286 DEGs were only found in the tolerant genotype. The Disease resistance response protein 206 and TIFY 10 A were differentially expressed, which were validated by quantitative real-time PCR. The differentially expressed genes identified through the mRNA transcriptome, along with the structure, provide a revealing insight into rice molecular response to salinity stress and underlie the salinity tolerance mechanism between genotypes.

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Soft rice with low amylose content (AC) ranging by 5-15% is a unique type with special eating and appearance quality and has become popular in the rice market. We resequenced the Wx-mp, a key allele from Milky Princess, a Japanese low AC variety, and found that the +473 mutation in exon 4 is the key mutation in both Wx-mp and its ancestor allele, Wx-mq from Milky Queen. Based on this functional mutation, an allelespecific PCR (AS-PCR) marker was developed and proven in a breeding population derived from a cross between a Chinese late variety Nan Keng 46 (Wx-mp/Wx-mp) and an early line Ning 63121(Wx-b/Wx-b). Based on the marker-aided selection by our newly developed AS-PCR marker for Wx-mp and the known ST10 marker for Stvb-i, a total of 12 Wx-mp homozygotes were selected from 198 F 2 progenies, and four of them were immune to rice stripe virus (RSV) with averagely 11.3 days earlier heading than Nan Keng 46 without significant change in grain yield.