Biology subjects

Furumizu, C.

Publications and source records attributed to Furumizu, C..

3 recordsLinked to original sources

bioRxiv2022

Solanum lycopersicum CLASS-II KNOX genes regulate fruit anatomy via gibberellin-dependent and independent pathways.

The pericarp is the predominant tissue determining the structural characteristics of most fruits. However, the molecular and genetic mechanisms controlling pericarp development remain only partially understood. Previous studies have identified that CLASS-II KNOX genes regulate fruit size, shape, and maturation in Arabidopsis thaliana and Solanum lycopersicum. Here we characterized the roles of the Solanum lycopersicum CLASS-II KNOX (TKN-II) genes in pericarp development via a detailed histological, anatomical, and karyotype analysis of the TKN-II knockdown (35S:amiR-TKN-II) fruits. We identify that 35S:amiR-TKN-II pericarps contain more cells around their equatorial perimeter and fewer cell layers than the control. In addition, the cell sizes but not the ploidy levels of these pericarps were dramatically reduced. Further, we demonstrate that fruit shape and pericarp layer number phenotypes of the 35S:amiR-TKN-II fruits can be overridden by the procera mutant, known to induce a constitutive response to the plant hormone gibberellin. However, neither the procera mutation nor exogenous gibberellin application can fully rescue the reduced pericarp width and cell size phenotype of 35S:amiR-TKN-II pericarps. Our findings establish that TKN-II genes regulate tomato fruit anatomy, acting via gibberellin to control fruit shape but utilizing a gibberellin-independent pathway to control the size of pericarp cells. HighlightTomato CLASS-II KNOX genes regulate fruit and pericarp anatomy via GA-dependent and independent pathways.

plant biology↗

bioRxiv2021

CLASS-II KNOX genes coordinate spatial and temporal patterns of the tomato ripening

Ripening is a complex developmental change of a mature organ, the fruit. In plants like a tomato, it involves softening, pigmentation, and biosynthesis of metabolites beneficial for the human diet. Examination of the transcriptional changes towards ripening suggests that redundant uncharacterized factors may be involved in the coordination of the ripening switch. Previous studies have demonstrated that Arabidopsis CLASS-II KNOX genes play a significant role in controlling the maturation of siliques and their transition to senescence. Here we examined the combined role of all four tomato CLASS-II KNOX genes in the maturation and ripening of fleshy fruits using an artificial microRNA targeting them simultaneously. As expected, the knockdown plants (35S::amiR-TKN-CL-II) exhibited leaves with increased complexity, reminiscent of the leaf phenotype of plants overexpressing CLASS-I KNOX, which antagonize CLASS-II KNOX gene functions. The fruits of 35S::amiR-TKN-CL-II plants were notably smaller than the control. While their internal gel/placenta tissue softened and accumulated the typical pigmentation, the pericarp color break took place ten days later than control, and eventually, it turned yellow instead of red. Additionally, the pericarp of 35S::amiR-TKN-CL-II fruits remained significantly firmer than control even after three weeks of shelf storage. Strikingly, the 35S::amiR-TKN-CL-II fruits showed early ethylene release and respiration peak, but these were correlated only with liquefaction and pigmentation of the internal tissues. Our findings suggest that CLASS-II KNOX genes are required to coordinate the spatial and temporal patterns of tomato fruit ripening. One sentence summaryTomato CLASS-II KNOX genes play antagonistic roles in the regulation of ripening at the internal fruit domains and pericarp.

developmental biology↗

bioRxiv2020

The Sequenced Genomes of Non-Seed Land Plants Reveal the (R)Evolutionary History of Peptide Signaling

An understanding of land plant evolution is a prerequisite for in-depth knowledge of plant biology. Here we extract and explore information hidden in the increasing number of sequenced plant genomes, from bryophytes to angiosperms, to elucidate a specific biological question - how peptide signaling evolved. To conquer land and cope with changing environmental conditions, plants have gone through transformations that must have required a revolution in cell-to-cell communication. We discuss peptides mediating endogenous and exogenous changes by interaction with receptors activating intracellular molecular signaling. Signaling peptides were discovered in angiosperms and operate in tissues and organs like flowers, seeds, vasculature, and 3D meristems that are not universally conserved across land plants. Nevertheless, orthologues of angiosperm peptides and receptors have been identified in non-flowering plants. These discoveries provoke questions regarding the co-evolution of ligands and their receptors, and whether de novo interactions in peptide signaling pathways may have contributed to generate novel traits in land plants. The answers to such questions will have profound implications for the understanding of evolution of cell-to-cell communication and the wealth of diversified terrestrial plants. Under this perspective we have generated, analyzed and reviewed phylogenetic, genomic, structural, and functional data to elucidate the evolution of peptide signaling.

evolutionary biology↗