In-plane Hall effect in rutile oxide films induced by the Lorentz force

The conventional Hall effect is linearly proportional to the field component or magnetization component perpendicular to a film. Despite the increasing theoretical proposals on the Hall effect to the in-plane field or magnetization in various special systems induced by the Berry curvature, such an unconventional Hall effect has only been experimentally reported in Weyl semimetals and in a heterodimensional superlattice. Here, we report an unambiguous experimental observation of the in-plane Hall effect (IPHE) in centrosymmetric rutile RuO2 and IrO2 single-crystal films under an in-plane magnetic field. The measured Hall resistivity is found to be proportional to the component of the applied in-plane magnetic field along a particular crystal axis and to be independent of the current direction or temperature. Both the experimental observations and theoretical calculations confirm that the IPHE in rutile oxide films is induced by the Lorentz force. Our findings can be generalized to ferromagnetic materials for the discovery of in-plane anomalous Hall effects and quantum anomalous Hall effects. In addition to significantly expanding knowledge of the Hall effect, this work opens the door to explore new members in the Hall effect family

The auxin response factor gene family in allopolyploid Brassica napus.

Auxin response factor (ARF) is a member of the plant-specific B3 DNA binding superfamily. Here, we report the results of a comprehensive analysis of ARF genes in allotetraploid Brassica napus (2n = 38, AACC). Sixty-seven ARF genes were identified in B. napus (BnARFs) and divided into four subfamilies (I-IV). Sixty-one BnARFs were distributed on all chromosomes except C02; the remaining were on Ann and Cnn. The full length of the BnARF proteins was highly conserved especially within each subfamily with all members sharing the N-terminal DNA binding domain (DBD) and the middle region (MR), and most contained the C-terminal dimerization domain (PBI). Twenty-one members had a glutamine-rich MR that may be an activator and the remaining were repressors. Accordingly, the intron patterns are highly conserved in each subfamily or clade, especially in DBD and PBI domains. Several members in subfamily III are potential targets for miR167. Many putative cis-elements involved in phytohormones, light signaling responses, and biotic and abiotic stress were identified in BnARF promoters, implying their possible roles. Most ARF proteins are likely to interact with auxin/indole-3-acetic acid (Aux/IAA) -related proteins, and members from different subfamilies generally shared many common interaction proteins. Whole genome-wide duplication (WGD) by hybridization between Brassica rapa and Brassica oleracea and segmental duplication led to gene expansion. Gene loss following WGD is biased with the An-subgenome retaining more ancestral genes than the Cn-subgenome. BnARFs have wide expression profiles across vegetative and reproductive organs during different developmental stages. No obvious expression bias was observed between An- and Cn-subgenomes. Most synteny-pair genes had similar expression patterns, indicating their functional redundancy. BnARFs were sensitive to exogenous IAA and 6-BA treatments especially subfamily III. The present study provides insights into the distribution, phylogeny, and evolution of ARF gene family

Evolution and expression analyses of the MADS-box gene family in <i>Brassica napus</i>

<div><p>MADS-box transcription factors are important for plant growth and development, and hundreds of MADS-box genes have been functionally characterized in plants. However, less is known about the functions of these genes in the economically important allopolyploid oil crop, <i>Brassica napus</i>. We identified 307 potential MADS-box genes (<i>BnMADSs</i>) in the <i>B</i>. <i>napus</i> genome and categorized them into type I (M_α, M_β, and M_γ) and type II (MADS DNA-binding domain, intervening domain, keratin-like domain, and C-terminal domain [MIKC]^c and MIKC*) based on phylogeny, protein motif structure, and exon-intron organization. We identified one conserved intron pattern in the MADS-box domain and seven conserved intron patterns in the K-box domain of the MIKC^c genes that were previously ignored and may be associated with function. Chromosome distribution and synteny analysis revealed that hybridization between <i>Brassica rapa</i> and <i>Brassica oleracea</i>, segmental duplication, and homologous exchange (HE) in <i>B</i>. <i>napus</i> were the main <i>BnMADSs</i> expansion mechanisms. Promoter cis-element analyses indicated that <i>BnMADSs</i> may respond to various stressors (drought, heat, hormones) and light. Expression analyses showed that homologous genes in a given subfamily or sister pair are highly conserved, indicating widespread functional conservation and redundancy. Analyses of <i>BnMADSs</i> provide a basis for understanding their functional roles in plant development.</p></div

MADS-box domain of MADSs-box genes in the <i>Brassica napus</i> (<i>BnMADSs</i>) genome.

<p>A multiple alignment analysis was performed using the MAFFT program. The sequence logos are based on the alignments of all type I (M_α, M_β, and M_γ) and type II (MIKC) <i>B</i>. <i>napus</i> MADS-box domains. Bit scores indicate the information content for each position in the sequence. Black and grey dots indicate 100%- and 90%-conserved residues, respectively.</p

Expression profiles of type II <i>BnMADSs</i> across different developmental stages and organs.

<p>The genes and their corresponding clade are on the right. The tissues used for expression analysis are indicated at the top of each column. GS, germinate seed; Hy, hypocotyl; Ao, anthocaulus; Ro, root; St, stem; Le, leaf; Cal, calyx; Cap, capillament; Pe, petal; Sta, stamen; Pi, pistil; SP, silique; Se, seed; SC, seed coat; Em, embryo; Co, cotyledon. s, seedling stage; b, bud stage; i, initial flowering stage; and f, full-bloom stage. The time after seed germination is indicated as 24, 48, and 72 h. The number of days after pollination (DAP) is indicated as 3, 19, 21, 30, 40, and 46 d. The colour bar represents log2 expression values (FPKM). The genes with weak or no expression are supplied in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0200762#pone.0200762.s004" target="_blank">S1 Table</a>.</p

Phylogenetic relationships of type II BnMADS proteins investigated in this study.

<p>A neighbor-joining tree representing relationships among 187 BnMADS proteins translated from <i>B</i>. <i>napus</i> and 45 from <i>Arabidopsis</i> are shown. The proteins are clustered into 16 subfamilies. Coloured dots indicate the corresponding intron distribution patterns, as shown in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0200762#pone.0200762.g003" target="_blank">Fig 3</a>.</p

Schematic diagram of intron distribution patterns within the K-box of proteins translated from type II <i>BnMADSs</i>.

<p>Alignment of the K-box domains is representative of 7 intron patterns, designated A to G. Intron locations are indicated by white triangles, and the number within each triangle indicates the splicing phases: 0 refers to phase 0; 1 to phase 1; and 2 to phase 2. The number of <i>BnMADSs</i> within each pattern is presented on the left. The correlation between intron distribution patterns and phylogenetic subfamilies is provided in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0200762#pone.0200762.g002" target="_blank">Fig 2</a>.</p

Classification of the cis-elements in <i>BnMADS</i> promoters.

<p>106 Cis-elements were identified in the promoters of all 307 <i>BnMADSs</i> and were classified into three main groups (A–C). The number of type I and type II genes with the same type of cis-element is marked in different colours.</p