In 74LH3213 stems at 8 WAP, white pith parenchyma containing dead, air-filled cells was preferentially located in the panicle base and in the second to sixth internodes (Fig. Error bars show SD (n = 3). In the trunks of woody plants, the xylem parenchyma cells are colourless and are believed to be involved chiefly in storing starch, oils, and other ergastic substances. S6A). Staining with Evans blue, an indicator of cell death, confirmed that dead pith parenchyma cells were present only in SKS stems (Fig. Secretion of sap. 5 AâC and SI Appendix, Fig. Annual Review of Phytopathology 22: 189–214. (H) Evans blue-stained cross-section images of the first internodes of SKS and MS3B stems at 11 WAP. 2C). Given that cell death is widely observed in pith parenchyma of flowering plant stems, we speculated that D may have a similar role in other flowering plants. The expression level of each gene in 74LH3123 was defined as 1.00. Common sorghum varieties include grain sorghum, forage sorghum, biomass sorghum, and sweet sorghum (10). Thus, the discovery of the involvement of the D gene in the programmed death of stem pith parenchyma cells will broadly contribute to agriculture and industry. Sugar and ethanol productivity from the sugar juice of grass stems depends on their water content. (A) Localization of D-GFP and ANAC074-GFP in nuclei (arrowheads) of Arabidopsis culture cells. D and its Arabidopsis ortholog encode master transcriptional switches that induce programmed death of stem pith parenchyma cells by activating autolytic enzymes. Consistent with this, most of the studied VNS members activate genes related to cell-wall formation and PCD (26, 31, 37). 5C), whereas the percentage of dead cells in these cell lines in the absence of estrogen was â¼10%, which was comparable with that in wild-type cells and LexA::NAC1 cell lines (Fig. Induction of D or ANAC074 also up-regulated the expression of other genes encoding autolytic enzymes, which generally function to execute PCD, including an aspartic endopeptidase (PASPA3), a serine carboxypeptidase-like acyltransferase (SCPL48), a bifunctional nuclease (BFN1), and a ribonuclease (RNS3) (29) (Fig. Error bars show SD (n = 3, *P < 0.05, **P < 0.005, ***P < 0.001). Plumbing a variety of historical data could offer important insights into trends in insect declines. 6D). A search for chemicals that inhibit or enhance the activity of D should offer new approaches to the breeding of untransformable plants. Thus, parenchyma cells play a vital role in the overall development of the plant, throughout its life. 5A) indicates that genomic DNA is degraded, and strongly supports the proposal that ANAC074 expression induces PCD. Parenchyma cells can function as storage sites for starches, proteins, oils, and so on, and they contribute support to the plant if they are turgid. We identified D as a single gene encoding a NAC transcription factor that controls the expression of genes involved in plant PCD. Sorghum has become the fifth most cultivated cereal crop in the world (9). 3E). These results suggest that at least three D subfamily members, sorghum D, Arabidopsis ANAC074, and rice OsD, share overlapping functions involved in cell death. Here, we identify the D gene and note that it is located on chromosome 6 in agreement with previous predictions. S4). On the other hand, in sorghum, as in maize, the death of stem tissues reduces stem strength, which increases the susceptibility to stem lodging and stem rot disease (41âââ44). contributed new reagents/analytic tools; M.F., Y.O., H.K., M.I., H.K.-K., H.I., and J.-i. Photosynthesis. function of phloem parenchyma. This work was supported by grants from the Ministry of Agriculture, Forestry, and Fisheries of Japan (Genomics for Agricultural Innovation, Grants QTL5503 and QTL5506); the JST [Core Research for Evolutional Science and Technology (CREST), Grant JPMJCR12B5 and PRESTO, Grant JPMJPR11B3]; the Ministry of Education, Culture, Sports, Science and Technology of Japan KAKENHI (Grant 16H01247); and the Japan Society for the Promotion of Science KAKENHI (Grants 16H06172 and 17H05019). D expression was lowest in the first and seventh internodes (Fig. The death of stem pith parenchyma cells has several effects in plants. S9). The difference in stem water contents between SKS and MS3B is readily observed by squeezing the stems (Movie S1). To confirm that D and ANAC074 directly target PCD-related genes, we performed two experiments using the 5â²-upstream region of CEP1, a gene that encodes a cysteine peptidase and is up-regulated by expression of D or ANAC074 in Arabidopsis culture cells (Fig. Storage of food 4. Relative LUC activity in protoplasts transfected with the effector construct harboring CaMV35Spro::::CaMV35Ster (the only regulatory elements) and the reporter construct harboring CEP1pro(â555)::LUC::CaMV35Ster was defined as 1.0. The pandemic and recent immigration restrictions have exacerbated the ongoing plight of life science trainees in the United States. The expression level in the first internode (IN1) of 74LH3213 was defined as 1.00. General definition and function of parenchyma cells in plants In plants, parenchyma cells (Gr. Error bars show SD (n = 3). These results provide an approach to breeding crops for sugar and energy production. Inhibiting a signaling pathway protects microgravity-exposed mice from losing muscle and bone mass, a study finds. D complements mutant anac074 plant phenotypes and induces ectopic PCD in Arabidopsis culture cells by up-regulating the Arabidopsis PCD-executing enzymes. The presence of intercellular substances, especially in diffuse parenchyma with vacuoles, determines the tissue’s role in gas exchange. 2. These results indicate that D, ANAC074, and OsD specifically induce cell death but do not induce secondary cell-wall formation, unlike VND6. The gene responsible for determining dry-stem and juicy-stem traits of sorghum has long been referred to as D. In this study, we identified an uncharacterized gene, Sobic.006G147400, as a candidate for D. We could not identify any other genes within the genomic region for D determined by our fine mapping. This is a spongy tissue also known as a mesenchymal tissue, in which several types of cells are lodged in their extracellular matrices. (B) Fine mapping of the D locus. The preparation has been stained with coriphosphin. para, “beside” + enchyma, “an infusion”) make up one of the three ground tissues, alongside collenchyma and sclerenchyma cells. 3C). Our phylogenic analysis indicated that D proteins belong to a subfamily that is close to the NAC1 subfamily within the NAC superfamily. Some of these arose in geographical areas near where sorghum is proposed to have been initially domesticated around 4000â3000 BC (9, 22) (SI Appendix, Fig. All images were acquired at 96 h after the addition of estrogen. SOKENDAI (The Graduate University for Advanced Studies, Japan Science and Technology Agency (JST), From thin to thick: Major transitions during stem development, Programmed cell death during plant growth and development, Autolysis in herbaceous, dicotyledonous plants: Experimental manipulation of pith autolysis in several cultivated species, Non-structural carbohydrate partitioning in grass stems: A target to increase yield stability, stress tolerance, and biofuel production, Stem pithiness in tomato plants: The effect of water-stress and the role of abscisic-acid, Role of cellulase in aerenchyma development in sunflower, Aerenchyma formation in the rice stem and its promotion by H, General and specific combining ability estimates for pith cell-death in stalk internodes of maize, Sorghum: Origin, History, Technology and Production, Genetics, Genomics and Breeding of Sorghum, QTLs for energy-related traits in a sweet x grain sorghum [, On the inheritance of certain stem characters in sorghum, Inheritance of smut resistance and juiciness of stalk in the sorghum cross, red amber X feterita, Location of major effect genes in sorghum (, Identification of quantitative trait loci for agronomically important traits and their association with genic-microsatellite markers in sorghum, Genomewide association for sugar yield in sweet sorghum, Combining next generation sequencing with bulked segregant analysis to fine map a stem moisture locus in sorghum (, DNA-binding domains of plant-specific transcription factors: Structure, function, and evolution, NAC transcription factors: Structurally distinct, functionally diverse, Arabidopsis NAC1 transduces auxin signal downstream of TIR1 to promote lateral root development, Technical advance: An estrogen receptor-based transactivator XVE mediates highly inducible gene expression in transgenic plants, Comparative genomics of NAC transcriptional factors in angiosperms: Implications for the adaptation and diversification of flowering plants, Arabidopsis VASCULAR-RELATED NAC-DOMAIN6 directly regulates the genes that govern programmed cell death and secondary wall formation during xylem differentiation, Wood cell-wall structure requires local 2D-microtubule disassembly by a novel plasma membrane-anchored protein, Only in dying, life: Programmed cell death during plant development, A conserved core of programmed cell death indicator genes discriminates developmentally and environmentally induced programmed cell death in plants, Morphological classification of plant cell deaths, Contribution of NAC transcription factors to plant adaptation to land, Transcription switches for protoxylem and metaxylem vessel formation, The CUP-SHAPED COTYLEDON1 gene of Arabidopsis regulates shoot apical meristem formation, The CUP-SHAPED COTYLEDON3 gene is required for boundary and shoot meristem formation in Arabidopsis, EIN3 and ORE1 accelerate degreening during ethylene-mediated leaf senescence by directly activating chlorophyll catabolic genes in Arabidopsis, NAC transcription factor ORE1 and senescence-induced BIFUNCTIONAL NUCLEASE1 (BFN1) constitute a regulatory cascade in Arabidopsis, VASCULAR-RELATED NAC-DOMAIN7 directly regulates the expression of a broad range of genes for xylem vessel formation, Mutation of WRKY transcription factors initiates pith secondary wall formation and increases stem biomass in dicotyledonous plants, Composition of cell walls isolated from cell types of grain sorghum stems, The genetic control of lignin deposition during plant growth and development, Seasonal trends in density and cell death in sorghum stalk tissue, Relationship of cell death patterns and spread of, Breeding for lodging resistance in sorghum, Proceedings of the 32nd Annual Corn and Sorghum Industry Research Conference, Breeding for resistance to root and stalk rots in Texas, Sorghum Root and Stalk Rots: A Critical Review, Proceedings of the National Academy of Sciences, Earth, Atmospheric, and Planetary Sciences, https://www.ddbj.nig.ac.jp/dra/index.html, www.pnas.org/lookup/suppl/doi:10.1073/pnas.1807501115/-/DCSupplemental, News Feature: To understand the plight of insects, entomologists look to the past, Opinion: We need to improve the welfare of life science trainees, Journal Club: Clues to Alzheimerâs disease onset in the aging female brain, Protecting against spaceflight-induced muscle and bone loss. 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