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Key message: A novel genomic region controlling thermotolerance at flowering was identified by the combination of whole genomic re-sequencing and bulked segregant analysis in maize. The increasing frequency of extreme high temperature has brought a great threat to the development of maize throughout its life cycle, especially during the flowering phase. However, the genetic basis of thermotolerance at flowering in maize remains poorly understood. Here, we characterized a thermotolerant maize ecotype Abe2 and dissected its genetic basis using a F2:8 recombinant inbred line (RIL) population generated from a cross between Abe2 and B73. After continuous high temperature stress above 35 °C for 17 days, Abe2 and B73 show distinct leaf scorching phenotype under field conditions. To identify the genomic regions associated with the phenotypic variation, we applied a combination of whole genomic re-sequencing and bulked segregant analysis, and revealed 10,316,744 SNPs and 1,488,302 InDels between the two parental lines, and 2,693,054 SNPs and 313,757 InDels between the two DNA pools generated from the thermos-tolerant and the sensitive individuals of the RIL, of which, 108,655 and 17,853 SNPs may cause nonsynonymous variations. Finally, a 7.41 Mb genomic region on chromosome 1 was identified, and 7 candidate genes were annotated to participate in high temperature-related stress response. A candidate gene Zm00001d033339 encoding a serine/threonine protein kinase was proposed to be the most likely causative gene contributing to the thermotolerance at flowering by involving in stomatal movement (GO: 0010119) via Abscisic acid (ABA) pathway (KO04075). This work could provide an opportunity for gene cloning and pyramiding breeding to improve thermotolerance at flowering in maize. [ABSTRACT FROM AUTHOR]

A nitrosation-reduction method had been applied for the modification of DCE-4 h. It was a kind of non-polar hypercrosslinked resin and synthesized by our group. The functional resin, NR-07, exhibited good adsorption performance for NACs (Nitroaromatics). The adsorption capacity of NR-07 for p-nitrobenzoic acid was almost 1.3 times as much as that of H-103 in 24 h. The adsorption rate of NR-07 calculated by the kinetic function was 1.6 times as much as that of DCE-4h. According to the EA analysis and IR spectrum, the amine and carbonyl group were introduced onto the polymer chains of NR-07. These hydrophilic chemical groups of NR-07 contributed to a higher liquid-film diffusion rate than that of DCE-4h. Besides, the pore volume within 0.46~4.3 nm increased after the modification process, which had a positive effect on the intra-particle diffusion process. [ABSTRACT FROM AUTHOR]

The plant hormone abscisic acid (ABA) plays an important role in fruit development. To analyze the transcriptional regulation of ABA signaling pathway-related genes during mulberry ( Morus alba L.) fruit development and ripening, 17 genes participating in ABA signal transduction were isolated from the Morus notabilis genome database, including five MnPYL, six MnPP2C, and six MnSnRK2 genes. The result of multiple sequence alignment revealed that their functional amino acid residues and domains are conserved within each gene family. The expression profiles of ABA signaling pathway-related genes in the fruit of Morus atropurpurea cv. Jialing No. 40 were measured by quantitative real-time polymerase chain reaction. The transcripts of MaPYL4, MaPP2C5, and MaSnRK2.6 were expressed at a relatively higher level during the entire development process. Moreover, the transcript levels of MaPYL1/3/5, MaPP2C2/4/5/6, and MaSnRK2.3/2.6 were lower during the early-maturation stage and higher during the post-maturation stage, which suggests that they may play a vital role in regulating mulberry fruit ripening. In addition, these genes showed strong responses to exogenous ABA, fluridone, glucose, and sucrose. This study also indicated that exogenous ABA, sucrose, and glucose may promote fruit maturity, while fluridone significantly inhibits fruit ripening. [ABSTRACT FROM AUTHOR]

Abscisic acid (ABA) 8′-hydroxylase is the key enzyme in the oxidative catabolism of ABA. CYP707A genes encode (+)-ABA 8′-hydroxylases that are involved in fruit ripening and abiotic stress responses. However, there are limited reports on the functions of CYP707A genes in mulberry. This study analyzed the transcriptional expression of CYP707A genes during fruit development and their response to exogenous ABA and uniconazole (UNI) treatment. Additionally, the expression patterns of CYP707A under stress conditions were explored in mulberry. We obtained six CYP707A gene ( MnCYP707A1- MnCYP707A6) sequences from Morus notabilis genome database. Multiple sequence alignment results showed high conservation within the MnCYP707A genes. The expression profiles of these genes during fruit development and under stress conditions were analyzed by quantitative reverse transcriptase polymerase chain reaction (qRT-PCR). During fruit development, the expression levels of MaCYP707A1, MaCYP707A3, MaCYP707A5, and MaCYP707A6 were higher at the primary stage and then sharply declined to a lower level at the late stage. The expression of MaCYP707A1 in the fruit quickly declined at 1 d after 50 mmol/L UNI treatment. In addition, under Sodium chloride (NaCl) (0.3 % (w/v) at germination stage and 0.6 % (w/v) at seedling stage) or polyethylene glyco (PEG) 6000 (5 % (w/v) at germination stage and 20 % (w/v) at seedling stage) stress, most of the MaCYP707A genes were up-regulated, but displayed different patterns. Tissue-specific patterns of the CYP707A family appear to be universal under stress conditions. In a short, MaCYP707A genes play overlapping roles in ABA catabolism and MaCYP707A1 may be the key gene expressed during fruit maturation. Most of these genes were induced by abiotic stress, and various expression patterns were observed among the MaCYP707A in multiple mulberry tissues at different growth periods. [ABSTRACT FROM AUTHOR]

The identification and functional characterization of natural variants in plants are essential for understanding phenotypic adaptation. Here we identify a molecular variation in At2g47310 that contributes to the natural variation in flowering time in Arabidopsis thaliana accessions. This gene, which we term SISTER of FCA (SSF), functions in an antagonistic manner to its close homolog FCA. Genome-wide association analysis screens two major haplotypes of SSF associated with the natural variation in FLC expression, and a single polymorphism, SSF-N414D, is identified as a main contributor. The SSF414N protein variant interacts more strongly with CUL1, a component of the E3 ubiquitination complex, than the SSF414D form, mediating differences in SSF protein degradation and FLC expression. FCA and SSF appear to have arisen through gene duplication after dicot-monocot divergence, with the SSF-N414D polymorphism emerging relatively recently within A. thaliana. This work provides a good example for deciphering the functional importance of natural polymorphisms in different organisms. Natural variation represents valuable source for gene discovery. Here, the authors show that a homolog of Flowering Control Locus A (FCA) functions in an antagonistic manner to FCA in regulating Arabidopsis flowering time through interacting with CUL1-E3 and modulating FLC expression. [ABSTRACT FROM AUTHOR]