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Your search keyword '"Shimada, Tomoo"' showing total 435 results
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435 results on '"Shimada, Tomoo"'

17. The Arabidopsis katamari2 Mutant Exhibits a Hypersensitive Seedling Arrest Response at the Phase Transition from Heterotrophic to Autotrophic Growth.

Author

Hosokawa, Chika, Yagi, Hiroki, Segami, Shoji, Nagano, Atsushi J, Koumoto, Yasuko, Tamura, Kentaro, Oka, Yoshito, Matsushita, Tomonao, and Shimada, Tomoo

Subjects
PHASE transitions, ARABIDOPSIS, ARREST, RNA sequencing, SEED technology
Abstract

Young seedlings use nutrients stored in the seeds to grow and acquire photosynthetic potential. This process, called seedling establishment, involves a developmental phase transition from heterotrophic to autotrophic growth. Some membrane-trafficking mutants of Arabidopsis (Arabidopsis thaliana), such as the katamari2 (kam2) mutant, exhibit growth arrest during seedling development, with a portion of individuals failing to develop true leaves on sucrose-free solid medium. However, the reason for this seedling arrest is unclear. In this study, we show that seedling arrest is a temporal growth arrest response that occurs not only in kam2 but also in wild-type (WT) Arabidopsis; however, the threshold for this response is lower in kam2 than in the WT. A subset of the arrested kam2 seedlings resumed growth after transfer to fresh sucrose-free medium. Growth arrest in kam2 on sucrose-free medium was restored by increasing the gel concentration of the medium or covering the surface of the medium with a perforated plastic sheet. WT Arabidopsis seedlings were also arrested when the gel concentration of sucrose-free medium was reduced. RNA sequencing revealed that transcriptomic changes associated with the rate of seedling establishment were observed as early as 4 d after sowing. Our results suggest that the growth arrest of both kam2 and WT seedlings is an adaptive stress response and is not simply caused by the lack of a carbon source in the medium. This study provides a new perspective on an environmental stress response under unfavorable conditions during the phase transition from heterotrophic to autotrophic growth in Arabidopsis. [ABSTRACT FROM AUTHOR]

Published
2024
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32. Plant ESCRT protein ALIX coordinates with retromer complex in regulating receptor-mediated sorting of soluble vacuolar proteins

Author

#NODATA#, Hu, Shuai, Li, Baiying, Wu, Fan, Zhu, Dongmei, Zouhar, Jan, Gao, Caiji, Shimada, Tomoo, Rojo, Enrique, Hara-Nishimura, Ikuko, Jiang, Liwen, Shen, Jinbo, #NODATA#, Hu, Shuai, Li, Baiying, Wu, Fan, Zhu, Dongmei, Zouhar, Jan, Gao, Caiji, Shimada, Tomoo, Rojo, Enrique, Hara-Nishimura, Ikuko, Jiang, Liwen, and Shen, Jinbo

Abstract

Vacuolar proteins play essential roles in plant physiology and development, but the factors and the machinery regulating their vesicle trafficking through the endomembrane compartments remain largely unknown. We and others have recently identified an evolutionarily conserved plant endosomal sorting complex required for transport (ESCRT)-associated protein apoptosis-linked gene-2 interacting protein X (ALIX), which plays canonical functions in the biogenesis of the multivesicular body/prevacuolar compartment (MVB/PVC) and in the sorting of ubiquitinated membrane proteins. In this study, we elucidate the roles and underlying mechanism of ALIX in regulating vacuolar transport of soluble proteins, beyond its conventional ESCRT function in eukaryotic cells. We show that ALIX colocalizes and physically interacts with the retromer core subunits Vps26 and Vps29 in planta. Moreover, double-mutant analysis reveals the genetic interaction of ALIX with Vps26 and Vps29 for regulating trafficking of soluble vacuolar proteins. Interestingly, depletion of ALIX perturbs membrane recruitment of Vps26 and Vps29 and alters the endosomal localization of vacuolar sorting receptors (VSRs). Taken together, ALIX functions as a unique retromer core subcomplex regulator by orchestrating receptor-mediated vacuolar sorting of soluble proteins.

Published
2022

34. Stomatal regulators are co-opted for seta development in the astomatous liverwortMarchantia polymorpha

Author

Moriya, Kenta C., primary, Shirakawa, Makoto, additional, Loue-Manifel, Jeanne, additional, Matsuda, Yoriko, additional, Lu, Yen-Ting, additional, Tamura, Kentaro, additional, Oka, Yoshito, additional, Matsushita, Tomonao, additional, Hara-Nishimura, Ikuko, additional, Ingram, Gwyneth, additional, Nishihama, Ryuichi, additional, Goodrich, Justin, additional, Kohchi, Takayuki, additional, and Shimada, Tomoo, additional

Published
2022
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47. Stomagen positively regulates stomatal density in Arabidopsis

Author

Sugano, Shigeo S., Shimada, Tomoo, Imai, Yu, Okawa, Katsuya, Tamai, Atsushi, Mori, Masashi, and Hara-Nishimura, Ikuko

Subjects
Biogeochemical cycles -- Analysis -- Research, Arabidopsis thaliana -- Physiological aspects -- Research, Stomata -- Physiological aspects -- Research, Environmental issues, Science and technology, Zoology and wildlife conservation
Abstract

Stomata in the epidermal tissues of leaves are valves through which passes C[O.sub.2], and as such they influence the global carbon cycle (1). The two-dimensional pattern and density of stomata in the leaf epidermis are genetically and environmentally regulated to optimize gas exchange (2). Two putative intercellular signalling factors, EPF1 and EPF2, function as negative regulators of stomatal development in Arabidopsis, possibly by interacting with the receptor-like protein TMM (3-6). One or more positive intercellular signalling factors are assumed to be involved in stomatal development, but their identities are unknown (7). Here we show that a novel secretory peptide, which we designate as Stomagen, is a positive intercellular signalling factor that is conserved among vascular plants. Stomagen is a 45-amino-acid, cysteine-rich peptide that is generated from a 102-amino-acid precursor protein designated as STOMAGEN. Both an in planta analysis and a semi-in-vitro analysis with recombinant and chemically synthesized Stomagen peptides showed that Stomagen has stomata-inducing activity in a dose-dependent manner. A genetic analysis showed that TMM is epistatic to STOMAGEN (At4g12970), suggesting that stomatal development is finely regulated by competitive binding of positive and negative regulators to the same receptor. Notably, STOMAGEN is expressed in inner tissues (the mesophyll) of immature leaves but not in the epidermal tissues where stomata develop. This study provides evidence of a mesophyll-derived positive regulator of stomatal density. Our findings provide a conceptual advancement in understanding stomatal development: inner photosynthetic tissues optimize their function by regulating stomatal density in the epidermis for efficient uptake of C[O.sub.2]., Stomatal development in leaves is negatively regulated by putative cell-surface receptors TOO MANY MOUTHS (TMM) and ERECTA family receptor-like kinases (ER, ERL1 and ERL2) (3,8). Two possible ligands of these [...]

Published
2010
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