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In the yeast Saccharomyces cerevisiae the guanosine triphosphatase (GTPase) Rho1 controls actin polarization and cell wall expansion. When cells are exposed to various environmental stresses that perturb the cell wall, Rho1 activates Pkc1, a mammalian Protein Kinase C homologue, and Mpk1, a mitogen activated protein kinase (MAPK), resulting in actin depolarization and cell wall remodeling. In this study, we demonstrate a novel feedback loop in this Rho1-mediated Pkc1-MAPK pathway that involves regulation of Rom2, the guanine nucleotide exchange factor of Rho1, by Mpk1, the end kinase of the pathway. This previously unrecognized Mpk1-depedent feedback is a critical step in regulating Rho1 function. Activation of this feedback mechanism is responsible for redistribution of Rom2 and cell wall synthesis activity from the bud to cell periphery under stress conditions. It is also required for terminating Rho1 activity toward the Pkc1-MAPK pathway and for repolarizing actin cytoskeleton and restoring growth after the stressed cells become adapted.

The seed dormancy characteristic is regarded as one of the most critical factors for pre-harvest sprouting (PHS) resistance. As a wild wheat relative species, Aegilops tauschii is a potential genetic resource for improving common wheat. In this study, an advanced backcross population (201 strains) containing only Ae. tauschii segments was developed by means of synthetic octaploid wheat (hexaploid wheat Zhoumai 18 × Ae. tauschii T093). Subsequently, seed dormancy rate (Dor) in the advanced backcross population was evaluated on the day 3, 5 and 7, in which 2 major QTLs (QDor-2D and QDor-3D) were observed on chromosomes 2D and 3D with phenotypic variance explained values (PVEs) of 10.25 and 20.40%, respectively. Further investigation revealed significant correlation between QDor-3D and Tamyb10 gene, while no association was found between the former and TaVp1 gene, implying that QDor-3D site could be of closer position to Tamyb10. The obtained quantitative trait locus sites (QTLs) in this work could be applied to develop wheat cultivars with PHS resistance.

Background: In recent years, nickel (Ni) has been widely applied in industrial and agricultural production and has become a kind of environmental pollution. In this study, the effect of nickel chloride (NiCl 2 ) with different concentrations on Arabidopsis genomic stability and DNA methylation has been demonstrated. The nucleolus variation and 18S rDNA methylation after NiCl 2 treatment have been analyzed.Results: The results are as follows: (1) The NiCl 2 could result in heritable genomic methylation variations. The genomic DNA methylation variations have been detected by methylation-sensitive amplified polymorphism (MSAP) molecular markers, and the result showed that after NiCl 2 treatment, there was methylation variation in T 0 generation seedlings, and partial site changes maintained in T 1 generation, which suggested that the effects of NiCl 2 on DNA methylation could be heritable in offspring. (2) NiCl 2 brought deformity and damage to nucleolar structure in Arabidopsis root tip cells, and the damage was positively correlated with the NiCl 2 concentration. 3. In the nucleolus, there was an increased cytosine methylation in 18S rDNA. The plant nucleolus variation and 18S rDNA methylation may be used as an examination indicator for Ni pollution in soil or plant. Conclusions: NiCl 2 application caused variation of DNA methylation of the Arabidopsis genomic and offspring's. NiCl 2 also resulted in nucleolar injury and deformity of root tip cells. The methylation rate of 18S rDNA also changed by adding NiCl 2 .

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Vehicular ad-hoc networks (VANETs) are promising research areas which mainly include three communication modes: vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I) and hybrid vehicle communication (HVC). But most of the current research on HVC mode in which vehicle nodes and infrastructures coexist only focuses on the analysis of the optimal single-type relay selection schemes. Inspired by this, in order to design an optimal multi-relay selection scheme which can select different types of relays simultaneously, and to compare it with single-type schemes, this paper firstly introduces a more practical network scenario by proposing a four-node system model which considers communication links between relays and building different channel models for different types of links. Four optimal relay selection protocols, which are named as Non-OR, SOR-AP, SOR-V and DOR-APV respectively, are then designed from the perspective of the different types and numbers of selected relays. The exact expressions of outage probability for each protocol are calculated based on the automatic repeat request (ARQ) protocol to evaluate the link interruption of the four protocols. Furthermore, this paper establishes a generalized 2dimensional discrete time Markov chain (DTMC) model and analyzes the one-step state transition probability for each protocol. The closed-form expressions of system throughput and energy efficiency are derived by calculating the steady state distribution of the DTMC. Finally, the simulation results summarize the suitable network scenarios for which the four proposed protocols are recommended by comparing their system performance, so as to provide some suggestions for the future design and optimization of vehicle mobile networks.

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Bainong male sterile (BNS) wheat (Triticum aestivum L.) is a thermo-sensitive genic male sterile line with excellent sterility and self-restoration. We focused on transcriptional profiles of differentially expressed probes between BNS sterile and fertile anthers. Anthers, rachis and spikes from sterile line and fertile line were collected. Extracted RNA was assayed using wheat expression microarray and Gene Ontology was analyzed using Cytoscape with ClueGO. An indole (indole-3-acetic acid: IAA) metabolism pathway sub-network was almost formed in all differentially expressed profiles between sterile and fertile samples. IAA sub-network contained four nodes of indole and alkaloid metabolism connecting main network via indole compounds. This sub-network was absent in rachis and intact in transformed fertile anthers, which was the main differently expressed metabolism pathway in F 1 anthers with restorer genes. Alkaloid metabolism was absent in sterile anthers. Abnormal metabolism of IAA may be involved in BNS sterility. BNS transformation may be regulated by the production of IAA and alkaloid metabolism pathway, which favor the safe utilization of the sterile line in hybrid wheat production.