Language：Japanese   Publisher：The Japan Society for Precision Engineering  

DOI： 10.2493/jjspe.89.685

CiNii Research

Language：Japanese   Publisher：Japanese Society of Soil Science and Plant Nutrition  

DOI： 10.20710/dojo.94.4_307

CiNii Research

Language：English   Publisher：Horticulture Research  

Grafting is a plant propagation technique widely used in agriculture. A recent discovery of the capability of interfamily grafting in Nicotiana has expanded the potential combinations of grafting. In this study, we showed that xylem connection is essential for the achievement of interfamily grafting and investigated the molecular basis of xylem formation at the graft junction. Transcriptome and gene network analyses revealed gene modules for tracheary element (TE) formation during grafting that include genes associated with xylem cell differentiation and immune response. The reliability of the drawn network was validated by examining the role of the Nicotiana benthamiana XYLEM CYSTEINE PROTEASE (NbXCP) genes in TE formation during interfamily grafting. Promoter activities of NbXCP1 and NbXCP2 genes were found in differentiating TE cells in the stem and callus tissues at the graft junction. Analysis of a Nbxcp1;Nbxcp2 loss-of-function mutant indicated that NbXCPs control the timing of de novo TE formation at the graft junction. Moreover, grafts of the NbXCP1 overexpressor increased the scion growth rate as well as the fruit size. Thus, we identified gene modules for TE formation at the graft boundary and demonstrated potential ways to enhance Nicotiana interfamily grafting.

DOI： 10.1093/hr/uhad072

Web of Science

Scopus

PubMed

Language：English   Publisher：Plant & cell physiology  

Nicotiana benthamiana is widely used as a model plant for dicotyledonous angiosperms. In fact, the strains used in research are highly susceptible to a wide range of viruses. Accordingly, these strains are subject to plant pathology and plant-microbe interactions. In terms of plant-plant interactions, N. benthamiana is one of the plants that exhibit grafting affinity with plants from different families. Thus, N. benthamiana is a good model for plant biology and has been the subject of genome sequencing analyses for many years. However, N. benthamiana has a complex allopolyploid genome, and its previous reference genome is fragmented into 141,000 scaffolds. As a result, molecular genetic analysis is difficult to perform. To improve this effort, de novo whole-genome assembly was performed in N. benthamiana with Hifi reads, and 1,668 contigs were generated with a total length of 3.1 Gb. The 21 longest scaffolds, regarded as pseudomolecules, contained a 2.8-Gb sequence, occupying 95.6% of the assembled genome. A total of 57,583 high-confidence gene sequences were predicted. Based on a comparison of the genome structures between N. benthamiana and N. tabacum, N. benthamiana was found to have more complex chromosomal rearrangements, reflecting the age of interspecific hybridization. To verify the accuracy of the annotations, the cell wall modification genes involved in grafting were analyzed, which revealed not only the previously indeterminate untranslated region, intron and open reading frame sequences but also the genomic locations of their family genes. Owing to improved genome assembly and annotation, N. benthamiana would increasingly be more widely accessible.

DOI： 10.1093/pcp/pcac168

Web of Science

Scopus

PubMed

Language：English   Publisher：Japanese Society for Plant Biotechnology  

<p>Reactive oxygen species (ROS) are critical for plant biological processes. As signaling molecules, ROS regulate plant growth and development through cell expansion, elongation, and programmed cell death. Furthermore, ROS production is induced by microbe-associated molecular patterns (MAMPs) treatment and biotic stresses, and contributes to plant resistance to pathogens. Thus, MAMP-induced ROS production has been an indicator for plant early immune responses or stress responses. One of widely used methods for the measurement is a luminol-based assay to measure extracellular ROS production with a bacterial flagellin epitope (flg22) as a MAMP elicitor. <i>Nicotiana benthamiana</i> is susceptible to a wide variety of plant pathogenic agents and therefore commonly used for ROS measurements. On the other hand, <i>Arabidopsis thaliana</i>, many of genetical lines of which are available, is also conducted to ROS measurements. Tests in an asterid <i>N. benthamiana</i> and a rosid <i>A. thaliana</i> can reveal conserved molecular mechanisms in ROS production. However, the small size of <i>A. thaliana</i> leaves requires many seedlings for experiments. This study examined flg22-induced ROS production in another member of the Brassicaceae family, <i>Brassica rapa</i> ssp. <i>rapa</i> (turnip), which has large and flat leaves. Our experiments indicated that 10 nM and 100 nM flg22 treatments induced high ROS levels in turnip. Turnip tended to have a lower standard deviation in multiple concentrations of flg22 treatment. Therefore, these results suggested that turnip can be a good material from the rosid clade for ROS measurement.</p>

DOI： 10.5511/plantbiotechnology.22.0823a

Web of Science

Scopus

PubMed

CiNii Research

Authorship：Lead author   Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (trade magazine, newspaper, online media)  

Authorship：Lead author   Language：English   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)  

DOI： 10.32285/glycoforum.24A2J

Authorship：Lead author   Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)  

Publisher：The Japanese Society of Plant Physiologists  

To identify rice genes that confer tolerance to environmental stresses, we are taking advantage of FOX Hunting System. In terms of physiology, abiotic stresses such as drought, salinity, heat or cold stress, provoke overlapping responses in plants, indicating the mechanisms of tolerance to these environmental stresses may share the same machinery. In this study, we are planning to perform two types of screening. The first one is "comprehensive FOX hunting" (c-FOX), where transgenic rice lines containing rice full-length cDNA are screened at T0 and/or T1 generations under salinity stress condition. We attempt to screen 2232 T1 transgenic lines, kindly provided by NIAS, and 215 independent T0 lines. The second strategy is "targeted FOX hunting" (t-FOX), for which 100 candidate genes (TOP100) are pre-selected based on the previous studies using multiple plant species, and used for examination resources to test whether overexpression of those genes confers stress tolerance under various environmental conditions. We are also evaluating existing rice cultivars with higher stress tolerance, to test as a host plant for further combinational analysis of the selected FOX genes.

DOI： 10.14841/jspp.2010.0.0922.0

Publisher：The Japanese Society of Plant Physiologists  

To identify rice genes that confer tolerance to environmental stresses, we are taking advantage of FOX Hunting System. In this study, we are planning to perform two types of screening. The first one is "conventional FOX hunting" (c-FOX), where transgenic rice lines containing rice full-length cDNA (rice FOX lines) are screened at T0 and T1 generations under salinity stress condition. The second strategy is "targeted FOX hunting" (t-FOX), for which ~100 candidate genes (TOP100) are listed for examination under various stress conditions to select most useful genes conferring stress tolerance. We are also evaluating rice cultivars with higher stress tolerance, to test as a host plant for further combinational analysis of the selected FOX genes. Details of the project and how to establish extremely tolerant lines using the selected materials will be discussed.

DOI： 10.14841/jspp.2009.0.0923.0

Application no：特願2015-142503  Date applied：2015.7

Announcement no：特開2016-103994  Date announced：2016.6

Application no：特願2006-232039 

Announcement no：特開2008-54512 

Application no：特願2002-187575 

Announcement no：特開2004-024160