The BR signaling pathway regulates primary root development and drought stress response by suppressing the expression of PLT1 and PLT2 in Arabidopsis thaliana

IntroductionWith the warming global climate, drought stress has become an important abiotic stress factor limiting plant growth and crop yield. As the most rapidly drought-sensing organs of plants, roots undergo a series of changes to enhance their ability to absorb water, but the molecular mechanism is unclear.Results and methodsIn this study, we found that PLT1 and PLT2, two important transcription factors of root development in Arabidopsis thaliana, are involved in the plant response to drought and are inhibited by BR signaling. PLT1- and PLT2-overexpressing plants showed greater drought tolerance than wild-type plants. Furthermore, we found that BZR1 could bind to the promoter of PLT1 and inhibit its transcriptional activity in vitro and in vivo. PLT1 and PLT2 were regulated by BR signaling in root development and PLT2 could partially rescue the drought sensitivity of bes1-D. In addition, RNA-seq data analysis showed that BR-regulated root genes and PLT1/2 target genes were also regulated by drought; for example, CIPK3, RCI2A, PCaP1, PIP1;5, ERF61 were downregulated by drought and PLT1/2 but upregulated by BR treatment; AAP4, WRKY60, and AT5G19970 were downregulated by PLT1/2 but upregulated by drought and BR treatment; and RGL2 was upregulated by drought and PLT1/2 but downregulated by BR treatment.DiscussionOur findings not only reveal the mechanism by which BR signaling coordinates root growth and drought tolerance by suppressing the expression of PLT1 and PLT2 but also elucidates the relationship between drought and root development. The current study thus provides an important theoretical basis for the improvement of crop yield under drought conditions

The Interaction between Graphene and Oxygen Atom

Based on the density function theory (DFT) method, the interaction between the graphene and oxygen atom is simulated by the B3LYP functional with the 6-31G basis set. Due to the symmetry of graphene (C54H18, D6h), a representative patch is put forward to represent the whole graphene to simplify the description. The representative patch on the surface is considered to gain the potential energy surface (PES). By the calculation of the PES, four possible stable isomers of the C54H18-O radical can be obtained. Meanwhile, the structures and energies of the four possible stable isomers, are further investigated thermodynamically, kinetically, and chemically. According to the transition states, the possible reaction mechanism between the graphene and oxygen atom is given

Immobilization of ionic liquids to covalent organic frameworks for catalyzing the formylation of amines with CO2 and phenylsilane

We presented the immobilization of ionic liquids on the channel walls of COFs using a post-synthetic strategy. The ionic [Et4NBr](50%)-Py-COF afforded a high CO2 adsorption capacity of 164.6mg g(-1) (1 bar, 273 K) and was developed as an effective heterogeneous catalyst for the transformation of CO2 into value-added formamides under ambient conditions

Effects of electroacupuncture on the kisspeptin-gonadotropin-releasing hormone (GnRH) /luteinizing hormone (LH) neural circuit abnormalities and androgen receptor expression of kisspeptin/neurokinin B/dynorphin neurons in PCOS rats

Abstract Background Polycystic ovary syndrome (PCOS) is characterized by hyperandrogenism, anovulation, and polycystic ovaries. Electroacupuncture (EA) can effectively improve hyperandrogenism and increase ovulation frequency in patients with PCOS. Pieces of suggest that androgen activity in the brain is associated with impaired steroid negative feedback in such patients. Studies have shown that EA regulated androgen receptor (AR) expression and local factor levels (such as anti-Müllerian hormone and inhibin B) in the ovary of PCOS rats. However, few studies have explored the effect of EA on androgen activity in the brain. Objective This study investigated the effect of EA on the kisspeptin-gonadotropin-releasing hormone (GnRH)/luteinizing hormone (LH) neural circuit and sex hormone receptor expression in the hypothalamus of PCOS rats. Methods PCOS signs were induced by letrozole administration, and the induced rats were treated with low-frequency EA at Guan Yuan acupoint (CV4). The effect of EA on PCOS-like signs was evaluated by observing changes in the body weight, ovarian quality, ovarian morphology, and serum sex hormone levels in rats. To explore the mechanism of the effect of EA on PCOS-like signs, the neuropeptide content of the kisspeptin-GnRH/LH neural circuit was assessed using enzyme-linked immunosorbent assay(ELISA); AR and estrogen receptor α (ERα) coexpression on kisspeptin/neurokinin B/dynorphin (KNDy) neurons was determined via triple-label immunofluorescence; and protein and mRNA expression of Kiss1, Ar, Esr1, and kisspeptin receptor (Kiss1r) was evaluated via western blotting and Reverse Transcription-Polymerase Chain Reaction (RT-PCR). Results The results revealed that the estrous cycle of rats in the EA treatment group recovered, and their body and ovary weight reduced; ovarian morphology improved; serum testosterone and LH levels significantly decreased; and kisspeptin, GnRH, and dynorphin levels in hypothalamic arcuate nucleus significantly decreased. Compared with controls, the number of AR/Kiss1-positive cells increased, number of ERα/Kiss1-positive cells decreased, and protein and mRNA expression of Kiss1, Ar, and Kiss1r significantly increased in PCOS rats. However, EA treatment reversed these changes and reduced the expression of Kiss1, Ar, and Kiss1r significantly. Conclusion Improvement in the reproductive hallmarks of PCOS rats via EA may be achieved by regulating the kisspeptin-GnRH/LH circuit via androgen activity attenuation. Thus, the results provide an experimental basis for acupuncture as an adjuvant medical therapy on PCOS