Summary Flavonoid accumulation in most fruits is enhanced by ethylene and jasmonate. However, little is known about the hormone functions related to red pear fruit coloration or their combined effects and potential underlying mechanisms. Various treatments were used to investigate the flavonoid metabolite profile and pear transcriptome to verify the effects of ethylene and jasmonate on flavonoid biosynthesis in red pear fruits as well as the mechanism behind this. Ethylene inhibits anthocyanin biosynthesis in red Chinese pear fruits, whereas jasmonate increases anthocyanin and flavone/isoflavone biosyntheses. The branching of the jasmonate‐induced flavonoid biosynthesis pathway is determined by ethylene. Co‐expression network and Mfuzz analyses revealed 4,368 candidate transcripts. Additionally, ethylene suppresses PpMYB10 and PpMYB114 expression via TF repressors, ultimately decreasing anthocyanin biosynthesis. Jasmonate induces anthocyanin accumulation through transcriptional or post‐translational regulation of TFs‐like MYB and bHLH in the absence of ethylene. However, jasmonate induces ethylene biosynthesis and the associated signalling pathway in pear, thereby decreasing anthocyanin production, increasing the availability of the precursors for flavone/isoflavone biosynthesis and enhancing deep yellow fruit coloration. We herein present new phenotypes and fruit coloration regulatory patterns controlled by jasmonate and ethylene, and confirm that the regulation of fruit coloration is complex.

To follow-up on our prior Part I review, this Part II review summarizes and provides updated literature on novel quinoline and quinazoline alkaloids isolated during the period of 2009-2016, together with the biological activity and the mechanisms of action of these classes of natural products. Over 200 molecules with a broad range of biological activities, including antitumor, antiparasitic and insecticidal, antibacterial and antifungal, cardioprotective, antiviral, anti-inflammatory, hepatoprotective, antioxidant, anti-asthma, antitussive, and other activities, are discussed. This survey should provide new clues or possibilities for the discovery of new and better drugs from the original naturally occurring quinoline and quinazoline alkaloids.

High acetylation in the promoter of a transcription factor gene is associated with sucrose accumulation in pear fruit by activating the expression of a sucrose transport gene.

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The fruit of Pyrus ussuriensis is typically climacteric. During ripening, the fruits produce a large amount of ethylene, and their firmness drops rapidly. Although the molecular basis of climacteric fruit ripening has been studied in depth, some aspects remain unclear. Here, we compared the transcriptomes of pre- and post-climacteric fruits of Chinese pear (P. ussuriensis c.v. Nanguo) using RNA-seq. In total, 3,279 unigenes were differentially expressed between the pre- and post-climacteric fruits. Differentially expressed genes (DEGs) were subjected to Gene Ontology analysis, and 31 categories were significantly enriched in the groups ‘biological process’, ‘molecular function’ and ‘cellular component’. The DEGs included genes related to plant hormones, such as ethylene, ABA, auxin, GA and brassinosteroid, and transcription factors, such as MADS, NAC, WRKY and HSF. Moreover, genes encoding enzymes related to DNA methylation, cytoskeletal proteins and heat shock proteins (HSPs) showed differential expression between the pre- and post-climacteric fruits. Select DEGs were subjected to further analysis using quantitative RT-PCR (qRT-PCR), and the results were consistent with those of RNA-seq. Our data suggest that in addition to ethylene, other hormones play important roles in regulating fruit ripening and may interact with ethylene signaling during this process. DNA methylation-related methyltransferase and cytoskeletal protein genes are also involved in fruit ripening. Our results provide useful information for future research on pear fruit ripening.

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To achieve high thermoelectric conversion efficiency in Bi 0.4 Sb 1.6 Te 3 (BST) alloy is vital for its applications in low-grade energy harvesting. Here, we show that 56% increase in the power factor (PF) (from 16 to 25 μW cm −1 K −2 ) and 32% reduction of lattice thermal conductivity κ L (from 0.56 to 0.38 W m −1 K −1 ) as well as an approximately four-fold decrease in bipolareffect contribution κ b (from 0.48 to 0.12 W m −1 K −1 ) can be achieved at 512 K through the incorporation of 0.2 vol % PbSe nanoparticles in the BST matrix. Analyses indicate that the remarkable increase in PF for the composite samples can be mainly attributed to strong electron scattering at the large interface barriers, inhibiting effectively the electron contribution to the total thermopower at elevated temperatures, while the large drop of κ L and κ b originates from enhanced phonon scattering by PbSe nanoinclusions as well as phase boundaries (among BST and PbSe nanophase) and suppression of electron transport, respectively. As a result, a maximum figure of merit (ZT) of 1.56 (at 400 K) and an average ZT (ZT ave ) of 1.44 in the temperature range of 300− 512 K are reached. Correspondingly, a record projected conversion efficiency η = 11% is achieved at the cold side 300 K and hot side 512 K in the BST-based composite incorporated with 0.2 vol % PbSe nanoinclusions.

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