Oxford University Press (OUP) Acta Medica Okayama 0032-0781 66 5 2024 SHORT AND CROOKED AWN, encoding the epigenetic regulator EMF1, promotes barley awn development 705 721 EN Koki Nakamura Institute of Plant Science and Resources, Okayama University Yuichi Kikuchi Institute of Plant Science and Resources, Okayama University Mizuho Shiraga Institute of Plant Science and Resources, Okayama University Toshihisa Kotake Graduate School of Science and Engineering, Saitama University Kiwamu Hyodo Institute of Plant Science and Resources, Okayama University Shin Taketa Institute of Plant Science and Resources, Okayama University Yoko Ikeda Institute of Plant Science and Resources, Okayama University The awn is a bristle-like extension from the tip of the lemma in grasses. In barley, the predominant cultivars possess long awns that contribute to grain yield and quality through photosynthesis. In addition, various awn morphological mutants are available in barley, rendering it a useful cereal crop to investigate the mechanims of awn development. Here, we identified the gene causative of the short and crooked awn (sca) mutant, which exhibits a short and curved awn phenotype. Intercrossing experiments revealed that the sca mutant induced in the Japanese cultivar (cv.) “Akashinriki” is allelic to the independently isolated moderately short-awn mutant breviaristatum-a (ari-a). Map-based cloning and sequencing revealed that SCA encodes the Polycomb group–associated protein EMBRYONIC FLOWER 1. We found that SCA affects awn development through the promotion of cell proliferation, elongation, and cell wall synthesis. RNA sequencing of cv. Bowman backcross-derived near-isogenic lines of sca and ari-a6 alleles showed that SCA is directly or indirectly involved in promoting the expression of genes related to awn development. Additionally, SCA represses various transcription factors essential for floral organ development and plant architecture, such as MADS-box and Knotted1-like homeobox genes. Notably, the repression of the C-class MADS-box gene HvMADS58 by SCA in awns is associated with the accumulation of the repressive histone modification H3K27me3. These findings highlight the potential role of SCA-mediated gene regulation, including histone modification, as a novel pathway in barley awn development. No potential conflict of interest relevant to this article was reported.

Japanese Society of Breeding Acta Medica Okayama 1344-7610 73 5 2023 Genomic traces of Japanese malting barley breeding in two modern high-quality cultivars, ‘Sukai Golden’ and ‘Sachiho Golden’ 435 444 EN Shin Taketa Institute of Plant Science and Resources, Okayama University June-Sik Kim Institute of Plant Science and Resources, Okayama University Hidekazu Takahashi Faculty of Food and Agricultural Sciences, Fukushima University Shunsuke Yajima NODAI Genome Research Center, Tokyo University of Agriculture Yuichi Koshiishi NODAI Genome Research Center, Tokyo University of Agriculture Toshinori Sotome Tochigi Prefectural Agricultural Experiment Station Tsuneo Kato Tochigi Prefectural Agricultural Experiment Station Keiichi Mochida Bioproductivity Informatics Research Team, RIKEN Center for Sustainable Resource Science Two modern high-quality Japanese malting barley cultivars, ‘Sukai Golden’ and ‘Sachiho Golden’, were subjected to RNA-sequencing of transcripts extracted from 20-day-old immature seeds. Despite their close relation, 2,419 Sukai Golden-specific and 3,058 Sachiho Golden-specific SNPs were detected in comparison to the genome sequences of two reference cultivars: ‘Morex’ and ‘Haruna Nijo’. Two single nucleotide polymorphism (SNP) clusters respectively showing the incorporation of (1) the barley yellow mosaic virus (BaYMV) resistance gene rym5 from six-row non-malting Chinese landrace Mokusekko 3 on the long arm of 3H, and (2) the anthocyanin-less ant2 gene from a two-row Dutch cultivar on the long arm of 2H were detected specifically in ‘Sukai Golden’. Using 221 recombinant inbred lines of a cross between ‘Ishukushirazu’ and ‘Nishinochikara’, another BaYMV resistance rym3 gene derived from six-row non-malting Japanese cultivar ‘Haganemugi’ was mapped to a 0.4-cM interval on the proximal region of 5H. Haplotype analysis of progenitor accessions of the two modern malting cultivars revealed that rym3 of ‘Haganemugi’ was independently introduced into ‘Sukai Golden’ and ‘Sachiho Golden’. Residual chromosome 5H segments of ‘Haganemugi’ surrounding rym3 were larger in ‘Sukai Golden’. Available results suggest possibilities for malting quality improvement by minimizing residual segments surrounding rym3. No potential conflict of interest relevant to this article was reported.

Oxford University Press (OUP) Acta Medica Okayama 1471-9053 62 3 2021 Mutations in a Golden2-Like Gene Cause Reduced Seed Weight in Barley albino lemma 1 Mutants 447 457 EN Shin Taketa Institute of Plant Science and Resources, Okayama University Momoko Hattori Institute of Plant Science and Resources, Okayama University Tsuneaki Takami Institute of Plant Science and Resources, Okayama University Eiko Himi Institute of Plant Science and Resources, Okayama University Wataru Sakamoto IInstitute of Plant Science and Resources, Okayama University The albino lemma 1 (alm1) mutants of barley (Hordeum vulgare L.) exhibit obvious chlorophyll-deficient hulls. Hulls are seed-enclosing tissues on the spike, consisting of the lemma and palea. The alm1 phenotype is also expressed in the pericarp, culm nodes and basal leaf sheaths, but leaf blades and awns are normal green. A single recessive nuclear gene controls tissue-specific alm1 phenotypic expression. Positional cloning revealed that the ALM1 gene encodes a Golden 2-like (GLK) transcription factor, HvGLK2, belonging to the GARP subfamily of Myb transcription factors. This finding was validated by genetic evidence indicating that all 10 alm1 mutants studied had a lesion in functionally important regions of HvGLK2, including the three alpha-helix domains, an AREAEAA motif and the GCT box. Transmission electron microscopy revealed that, in lemmas of the alm1.g mutant, the chloroplasts lacked thylakoid membranes, instead of stacked thylakoid grana in wild-type chloroplasts. Compared with wild type, alm1.g plants showed similar levels of leaf photosynthesis but reduced spike photosynthesis by 34%. The alm1.g mutant and the alm1.a mutant showed a reduction in 100-grain weight by 15.8% and 23.1%, respectively. As in other plants, barley has HvGLK2 and a paralog, HvGLK1. In flag leaves and awns, HvGLK2 and HvGLK1 are expressed at moderate levels, but in hulls, HvGLK1 expression was barely detectable compared with HvGLK2. Barley alm1/Hvglk2 mutants exhibit more severe phenotypes than glk2 mutants of other plant species reported to date. The severe alm1 phenotypic expression in multiple tissues indicates that HvGLK2 plays some roles that are nonredundant with HvGLK1. No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 1344-7610 61 1 2011 Expression and functional analysis of the barley Nud gene using transgenic rice 35 42 EN Katsuyuki Kakeda Mie Univ, Grad Sch Bioresources Norimitsu Ishihara Mie Univ, Grad Sch Bioresources Yohei Izumi Okayama Univ, Inst Plant Sci & Resources Kazuhiro Sato Okayama Univ, Inst Plant Sci & Resources Shin Taketa Okayama Univ, Inst Plant Sci & Resources Most cereal crops have hulless grains (naked caryopses) with a free-threshing trait, whereas the majority of barley cultivars show hulled (covered) caryopses. The naked caryopsis in barley is genetically controlled by a single locus, nod. The Nud gene (the covered caryopsis allele) encodes an ethylene response factor (ERF) family transcription factor that regulates a lipid biosynthetic pathway. For functional analysis of the barley Nud gene, we produced transgenic rice expressing Nod in the developing caryopses. All transgenic lines had caryopses that were easily dehulled at maturity, indicating that the naked caryopsis phenotype remained in spite of expression of the Nod transgene. Histochemical and lipid analyses of the transgenic rice caryopses did not show increased lipid accumulation on the surface of developing caryopses, suggesting that the Nud-mediated lipid pathway may not function in rice caryopses. The predicted rice ortholog of Nod, Os06ERF was expressed specifically in the developing caryopses. However, expression of Os06ERF ceased at an earlier developmental stage than that of the native Nod gene in barley caryopses, which was also the case for expression of the Nod transgene. This raises the alternative hypothesis that the timing of Nod expression may be critical for activating the pathway for hull-caryopsis adhesion. No potential conflict of interest relevant to this article was reported.

岡山大学資源生物科学研究所 Acta Medica Okayama 0916-930X 5 1 1997 コムギ属植物における穀粒のフェノール反応の変異およびフェノール反応に関与する遺伝子の座乗染色体 61 68 EN Cheng Lin Chang Shin Takeda Kazuyoshi Takeda A total of 3,606 accessions of the genus Triticum involving diploid, tetraploid, hexaploid, and synthetic wheat and 7 Aegilops materials were tested for the phenol reaction in kernels. All hexaploid wheat showed a positive reaction to phenol, but deffered in staining degree. One of the synthetic wheat lines showed a negative reaction to phenol. Using monosomics, ditelosomics and nulli-tetrasomics in the common wheat cv Chinese Spring (Triticum aestivum L.), and Langdon (Triticum turgidum var. durum) disomic substitutions, genes controlling phenol reaction of kernels were located on chromosomes 2A, 2B and 2D. Synteny of the chromosome region involving the phenol reaction gene in some gramineous plants was discussed. No potential conflict of interest relevant to this article was reported.