Multiomics analyses unveil the involvement of microRNAs in pear fruit senescence under high- or low-temperature conditions.

Senescence leads to declines in fruit quality and shortening of shelf life. It is known that low temperatures (LTs) efficiently delay fruit senescence and that high temperatures (HTs) accelerate senescence. However, the molecular mechanism by which temperature affects senescence is unclear. Herein, through multiomics analyses of fruits subjected to postharvest HT, LT, and room temperature treatments, a total of 56 metabolic compounds and 700 mRNAs were identified to be associated with fruit senescence under HT or LT conditions. These compounds could be divided into antisenescent (I→III) and prosenescent (IV→VI) types. HT affected the expression of 202 mRNAs to enhance the biosynthesis of prosenescent compounds of types V and VI and to inhibit the accumulation of antisenescent compounds of types II and III. LT affected the expression of 530 mRNAs to promote the accumulation of antisenescent compounds of types I and II and to impede the biosynthesis of prosenescent compounds of types IV and V. Moreover, 16 microRNAs were isolated in response to HT or LT conditions and interacted with the mRNAs associated with fruit senescence under HT or LT conditions. Transient transformation of pear fruit showed that one of these microRNAs, Novel_188, can mediate fruit senescence by interacting with its target Pbr027651.1. Thus, both HT and LT conditions can affect fruit senescence by affecting microRNA-mRNA interactions, but the molecular networks are different in pear fruit.

[Electroacupuncture of "Zusanli" (ST 36) Raises Muscular Force by Adjusting AMPK/PGC-1 α Signaling in Rats with Chronic Fatigue Syndrome].

OBJECTIVE: To observe the effect of electroacupuncture (EA) of "Zusanli" (ST 36) on mitochondrial oxidative stress of skeletal muscle in rats with chronic fatigue syndrome (CFS) based on adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK)/ peroxlsome proliferator-activated receptor-γ coactivator-1 α (PGC-1 α) signaling, in order to reveal its mechanism underlying improvement of CFS. METHODS: Forty SD rats were randomly divided into normal control, CFS model, EA-Zusanli (ST 36) and EA-non-acupoint groups (n=10 rats in each group). The CFS model was established by forced exhausted load-bearing swimming (twice daily), chronic constraint (1 h) and sleep deprivation (20 h/day) for 14 days. Following modeling, EA (2 Hz/100 Hz, 2 V) was applied to bilateral Zusanli (ST 36) or non-acupoint (about 10-15 mm superior to the bilateral Iliac creast and about 20 mm lateral to the posterior median line) for 20 min, once a day for 10 days. The expression levels of ATP synthase, AMPK, phosphorylated (p)-AMPK, silent mating type information regulation 2 homolog-1 (SIRT 1) and PGC-1 α proteins, and ATP synthase, SIRT 1 and PGC-1 α mRNAs of the quadriceps femoris muscle were detected by Western blot and fluorescence quantitative PCR, respectively. The rats' grabbing force was detected by using a grabbing-force detector. RESULTS: Compared with the normal group, the grabbing force, and the expression levels of ATP synthase and PGC-1 α proteins and mRNAs were significantly decreased (P<0.05, P<0.01), while the expression of SIRT 1 protein was significantly up-regulated (P<0.05) in the CFS model group. Following EA intervention, the grabbing force and the expression levels of ATP synthase mRNA, SIRT 1 and PGC-1 α proteins and mRNAs, and p-AMPK/AMPK were significantly up-regulated in the EA-Zusanli (ST 36) group (P<0.05, P<0.01). CONCLUSION: EA of ST 36 can raise the grabbing force of CFS rats, which may be related to its effects in up-regulating the expression of ATP synthase mRNA, SIRT 1 and PGC-1 α proteins and mRNAs, and p-AMPK/AMPK to reduce mitochondrial oxidative stress reaction and in increasing ATP synthesis.

[Construction of the oocyte-specific expressing phiC31 integrase vector pZP3-INT and its expression in mouse oocytes].

Streptomyces phage phiC31 integrase is a site-specific recombinase, which can catalyze site-specific, unidirectional recombination between the attP site and attB site. To explore whether it can be used to mediate the recombination of specific gene in oocytes, GV-stage oocytes were collected from 3-week-old Kunming White mice by puncturing antral follocles with a sharp needle, and micro-injected with oocyte-specific expressing phiC31 integrase vector pZP3-INT and site -specific recombination detection vector pBCPB+. phiC31 integrase mRNA were detected by RT-PCR and the recombination of pBCPB+ was evaluated by PCR in mouse oocytes at 48 h after injection. Both can get corresponding bands. These results indicated that the expression of phiC31 integrase can be driven by ZP3 promoter efficiently and phiC31 integrase can mediate the site-specific recombination between attP site and attB site in mouse GV-stage oocytes. It could be a powerful tool for the study of recombination of specific gene in mouse oocytes and would provide an alternative way for the mouse oocyte genome manipulation.