Color variations in the seed coat and other organs of the soybean emerged during the domestication process. Most of the known genes involved in the pigmentation of each organ are involved in flavonoid synthesis. In this study, we investigated the coloration in each organ of soybean using the FUKUSHIMA_Panel of 333 soybean varieties. We analyzed the expression of genes involved in flavonoid biosynthesis pathways in each organ and found that the activities of specific branches of the flavonoid pathway differ among organs, explaining the organ-specific differences in color determination. Combinations of four known color-related genes (I, R, W1, and T) altered functional pathways and seed coat pigmentation in the seed coat, resulting in diverse seed coat colors. In this context, we found that the reddish seed coat pigment is a pelargonidin-3-glucoside (Pg3G) anthocyanin, and its causative gene is a combination of non-functional haplotypes of W1 and T, previously unidentified. Finally, the process of colorlessness in domestication and breeding was investigated. The ii or I locus was selected in the domestication and early breeding process. In contrast, a combination of non-functional R and T haplotypes was selected in the modern breeding process to completely inactivate the flavonoid biosynthesis pathway to produce seeds with good appearance.

In genomic breeding, approaches centered on genome-wide association study (GWAS) have elucidated many loci underlying target traits. However, the conventional approaches focusing on the effects of independent genetic factors do not properly reflect phenotypic variation arising from interactions between genetic background and environmental conditions. In this study, regarding yield-related traits in rice, we focused on two strong GWAS peaks for grain number (GN), corresponding to the known genes NARROW LEAF1 (NAL1) and Oryza sativa SPINDLY (OsSPY). NAL1 negatively regulated GN in a nitrogen-dependent manner, whereas OsSPY positively regulated GN irrespective of nitrogen conditions. Examination of haplotype combinations across nitrogen conditions using imbalance-aware statistical estimation allowed modeling of the interaction effects of NAL1 and OsSPY on GN. Specifically, under low nitrogen conditions, the effect of NAL1 was markedly enhanced, being approximately two-fold greater in the background of the low-activity OsSPY haplotype than in that of the high-activity haplotype. These findings provide a framework integrating haplotype combinations with environmental context to better explain phenotypic variation, thereby highlighting genotype-by-genotype-by-environment (G × G × E) interactions underlying rice performance under variable environmental conditions. This perspective complements and extends conventional genetic approaches, enabling a deeper understanding of complex trait architecture in natura.

Plants recognize environmental information as external signals, which they use to coordinate developmental processes for their survival and reproduction. In the agricultural production of rice, the primary staple crop worldwide, soil nitrogen (N) is an important environmental factor. Heading date, a key trait for rice quality and yield, is modulated by N fertilisation; however, the molecular mechanisms underlying N-dependent flowering regulation remain unclear. Here, we conduct a genome-wide association study using differences in heading dates of Japanese rice cultivars grown under different N conditions. We identify Hd6, which is known to be involved in photoperiodic flowering regulation, as a key signalling component in the phenotypic variation observed under various N conditions. Further analyses using near-isogenic lines reveal that not only Hd6 but also Hd2 and Hd1 are required for the delayed flowering caused by N fertilisation. We also discover that Hd6 regulates floral inducer genes by stabilizing Hd2 through phosphorylation in response to N conditions and that the Hd6-Hd2 module can counteract the transcriptional regulation of Hd1. This study elucidates the molecular pathway directly linking N responses to flowering regulation in rice, providing insights for novel breeding and cultivation strategies.

The transition from dormancy to germination marks the initial stage of the plant life cycle, with its intensity, synchronicity, and timing being critical for crop growth, development, and adaptation to complex climate conditions. This review synthesizes recent advances with classic molecular mechanisms of dormancy and germination, including environmental responses and signaling cascades. We integrate these independent studies to provide a comprehensive perspective on the complex regulatory networks and discuss novel insights into how rice seeds perceive and respond to environmental cues during this transition, particularly focusing on stress tolerance to temperature and flooding. We aim to bridge the understanding of the molecular mechanisms of dormancy and germination with their breeding applications. Specifically, we discuss gene targets and feasible strategies for the genetic improvement of pre-harvest sprouting and direct-seeded rice, two key traits essential for climate resilience, both of which involve dormancy and germination. Finally, we propose the concept of engineering germination-smart varieties endowed with intelligent environmental adaptation.

植物ホルモンとは光やストレスなどの環境要因に適応するように植物の成長を制御している物質である．その植物ホルモンの一つであるジベレリン（gibberellin; GA）は植物細胞の伸長や，種子の発芽，開花などの多様な発達過程の制御を司っている．GAの生理作用はDELLAタンパク質と呼ばれる植物固有の転写因子様タンパク質によって抑制されており，このDELLAがGA依存的に分解されることでGAの生理作用が誘導されることがわかっている．これまでの研究によりDELLAがどのように分解されるのかについては，かなりの部分が明らかになっているのに対し，DELLAがどのように機能しているのかについてはいまだ明らかになっていない部分が多い．本稿では，まずGAシグナルとその抑制因子DELLAについての概略を説明し，その後，現在提唱されているDELLAの2つの主な作用機序について具体例を挙げつつ解説する．特に最近筆者らを含め多くの研究者によってその存在が確かなものになった転写活性化因子としての作用に焦点を当てる．

The research and development of the JAXA 150-mN ion engine are in progress. The objective of this activity is to establish the ion propulsion technology for future applications, which require high thrust levels, such as orbit raising and deep space exploration. Current efforts are directed to improvement in endurance of the thruster, power conditioner development, and test facility improvement because sufficiently high thruster performance has already been achieved. An endurance test of a main hollow cathode is being conducted. Back sputtering characteristics of a test facility were improved for a coming thruster endurance test. Wide range operation of the thruster, neutralizer characterization tests, and basic study on power processing units were also conducted.

Low-molecular-weight glutenin subunit (LMW-GS) composition in common wheat is one of the critical determinants of gluten properties. However, the nomenclature of Glu-3 encoding LMW-GSs has not been consistent among laboratories, due to the complexity of the LMW-GSs and the distinct separation methods used by different researchers. It is very important to unify the nomenclature systems in current use, to facilitate the sharing of information about the effects of individual LMW-GS on gluten properties. We therefore shared 103 cultivars having various Glu-A3, Glu-B3 and Glu-D3 alleles from Argentina, China, France, Japan and Mexico. Using 1D SDS-PAGE and 2D analyses, we found differences in nomenclature particularly for Glu-A3 and Glu-B3, including new Glu3 alleles among laboratories. We propose a new list of standard cultivars representing Glu-3 alleles.