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Hybrid rice (Oryza sativa) generally outperforms its inbred parents in yield and stress tolerance, a phenomenon termed heterosis, but the underlying mechanism is not completely understood. Here, we combined transcriptome, proteome, physiological, and heterosis analyses to examine the salt response of super hybrid rice Chaoyou1000 (CY1000). In addition to surpassing the mean values for its two parents (mid‐parent heterosis), CY1000 exhibited a higher reactive oxygen species scavenging ability than both its parents (over‐parent heterosis or heterobeltiosis). Nonadditive expression and allele‐specific gene expression assays showed that the glutathione S‐transferase gene OsGSTU26 and the amino acid transporter gene OsAAT30 may have major roles in heterosis for salt tolerance, acting in an overdominant fashion in CY1000. Furthermore, we identified OsWRKY72 as a common transcription factor that binds and regulates OsGSTU26 and OsAAT30. The salt‐sensitive phenotypes were associated with the OsWRKY72paternal genotype or the OsAAT30maternal genotype in core rice germplasm varieties. OsWRKY72paternal specifically repressed the expression of OsGSTU26 under salt stress, leading to salinity sensitivity, while OsWRKY72maternal specifically repressed OsAAT30, resulting in salinity tolerance. These results suggest that the OsWRKY72–OsAAT30/OsGSTU26 module may play an important role in heterosis for salt tolerance in an overdominant fashion in CY1000 hybrid rice, providing valuable clues to elucidate the mechanism of heterosis for salinity tolerance in hybrid rice. [ABSTRACT FROM AUTHOR]

Summary: The development of embryo sacs is crucial for seed production in plants, but the genetic basis regulating the meiotic crossover formation in the macrospore and microspore mother cells remains largely unclear. Here, we report the characterization of a spontaneous rice female sterile variation 1 mutant (fsv1) that showed severe embryo sacs abortion with low seed‐setting rate. Through map‐based cloning and functional analyses, we isolated the causal gene of fsv1, OsMLH3 encoding a MutL‐homolog 3 protein, an ortholog of HvMLH3 in barley and AtMLH3 in Arabidopsis. OsMLH3 and OsMLH1 (MutL‐homolog 1) interact to form a heterodimer (MutLγ) to promote crossover formation in the macrospore and microspore mother cells and development of functional megaspore during meiosis, defective OsMLH3 or OsMLH1 in fsv1 and CRISPR/Cas9‐based knockout lines results in reduced type I crossover and bivalent frequency. The fsv1 and OsMLH3‐knockout lines are valuable germplasms for development of female sterile restorer lines for mechanized seed production of hybrid rice. [ABSTRACT FROM AUTHOR]

Direct magnetoelectric (ME) coupling between magnetic and ferroelectric orders, which can be realized in spiral magnets, is vital in technological applications of multifunctional materials. Multisusceptible BaFe12O19 is noteworthy for its excellent magnetic, dielectric properties and thus the application in high‐density information storage, while its collinear spin structure limits the emergence of ferroelectrics and ME coupling. In this work, nonzero Dzyaloshinskii–Moriya (DM) interaction is created by partial substitution of the spin‐down Fe3+ sites to induce conical spin structure in BaFe12O19. Larger In3+ ions are introduced and prefer to occupy the spin‐down 4f1 and 4f2 lattice sites. The evolution of magnetization versus temperature adduces evidence of conical magnetic structure. As a result, direct ME and magnetodielectric coupling are obtained in In‐doped BaFe12O19 ceramics. An interlayer DM interaction model is built to discuss the intrinsic relationship among crystal structure, noncollinear magnetic structure, and ionic substitution. Moreover, BaZn0.9Zr0.9Fe10.2O19 ceramics are also prepared, and exhibit noncollinear magnetic structure and direct ME coupling since Zn2+ and Zr4+ also possess larger radii than Fe3+ and prefer to enter the spin‐down sites. The present result provides a feasible avenue to develop multiferroic and magnetoelectric coupling in ubiquitous M‐type hexaferrite. [ABSTRACT FROM AUTHOR]

Fe‐doped (Ba0.7Ca0.3)TiO3‐Ba(Zr0.2Ti0.8)O3 (BCZT) ceramics are prepared by a conventional solid‐state reaction method, and their structure, multiferroic, and coupling properties are investigated. Ferromagnetism and magnetoelectric coupling are successfully realized by Fe3+ doping. Meanwhile, Fe3+ doping in BCZT results in a gradual transition from typical ferroelectrics to relaxor ferroelectrics or even quantum paraelectrics. In consequence, obvious magnetodielectric (MD) effect is observed only among the morphotropic phase boundary (MPB) temperature range. For (Ba1.7Ca0.3)(Zr0.2Ti1.7Fe0.1)O6 ceramics, the coexistence of ferroelectricity and ferromagnetism along with a large MD effect is obtained below 200 K. Herein, the results highlight the role of MPB on the magnetoelectric coupling of ferroelectrics with a percolating of magnetic ions. [ABSTRACT FROM AUTHOR]