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Ishimaru T, Parween S, Saito Y, Masumura T, Kondo M, Sreenivasulu N. Laser microdissection transcriptome data derived gene regulatory networks of developing rice endosperm revealed tissue- and stage-specific regulators modulating starch metabolism. Plant Mol Biol 2022; 108:443-467. [PMID: 35098404 PMCID: PMC8894313 DOI: 10.1007/s11103-021-01225-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Accepted: 11/19/2021] [Indexed: 06/14/2023]
Abstract
Laser microdissection applied on the developing rice endosperm revealed tissue- and stage-specific regulators modulating programmed cell death and desiccation tolerance mechanisms in the central starchy endosperm following starch metabolism. Rice (Oryza sativa L.) filial seed tissues are heterozygous in its function, which accumulate distinct storage compounds spatially in starchy endosperm and aleurone. In this study, we identified the 18 tissue- and stage-specific gene co-regulons in the developing endosperm by isolating four fine tissues dorsal aleurone layer (AL), central starchy endosperm (CSE), dorsal starchy endosperm (DSE), and lateral starchy endosperm (LSE) at two developmental stages (7 days after flowering, DAF and 12DAF) using laser microdissection (LM) coupled with gene expression analysis of a 44 K microarray. The derived co-expression regulatory networks depict that distinct set of starch biosynthesis genes expressed preferentially at first in CSE at 7 DAF and extend its spatial expression to LSE and DSE by 12 DAF. Interestingly, along with the peak of starch metabolism we noticed accumulation of transcripts related to phospholipid and glycolipid metabolism in CSE during 12 DAF. The spatial distribution of starch accumulation in distinct zones of starchy endosperm contains specific transcriptional factors and hormonal-regulated genes. Genes related to programmed cell death (PCD) were specifically expressed in CSE at 12DAF, when starch accumulation was already completed in that tissue. The aleurone layer present in the outermost endosperm accumulates transcripts of lipid, tricarboxylic acid metabolism, several transporters, while starch metabolism and PCD is not pronounced. These regulatory cascades are likely to play a critical role in determining the positional fate of cells and offer novel insights into the molecular physiological mechanisms of endosperm development from early to middle storage phase.
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Affiliation(s)
- Tsutomu Ishimaru
- NARO Institute of Crop Science, NARO, 2-1-18 Kannondai, Tsukuba, Ibaraki 305-8518 Japan
- Hokuriku Research Station, Central Region Agricultural Research Center, National Agriculture and Food Research Organization (CARC/NARO), 1-2-1 Inada, Joetsu, Niigata 941-0193 Japan
| | - Sabiha Parween
- International Rice Research Institute (IRRI), DAPO Box 7777, Metro Manila, The Philippines
| | - Yuhi Saito
- Graduate School of Life and Environmental Science, Kyoto Prefectural University, Shimogamo, Sakyo-ku, Kyoto, 606-8522 Japan
| | - Takehiro Masumura
- Graduate School of Life and Environmental Science, Kyoto Prefectural University, Shimogamo, Sakyo-ku, Kyoto, 606-8522 Japan
| | - Motohiko Kondo
- NARO Institute of Crop Science, NARO, 2-1-18 Kannondai, Tsukuba, Ibaraki 305-8518 Japan
- Graduate School of Bioagricultural Sciences, Nagoya University, Furo, Chikusa, Nagoya, 464-8601 Japan
| | - Nese Sreenivasulu
- International Rice Research Institute (IRRI), DAPO Box 7777, Metro Manila, The Philippines
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Takafuji Y, Shimizu-Sato S, Ta KN, Suzuki T, Nosaka-Takahashi M, Oiwa T, Kimura W, Katoh H, Fukai M, Takeda S, Sato Y, Hattori T. High-resolution spatiotemporal transcriptome analyses during cellularization of rice endosperm unveil the earliest gene regulation critical for aleurone and starchy endosperm cell fate specification. J Plant Res 2021; 134:1061-1081. [PMID: 34279738 DOI: 10.1007/s10265-021-01329-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Accepted: 07/05/2021] [Indexed: 06/13/2023]
Abstract
The major tissues of the cereal endosperm are the starchy endosperm (SE) in the inner and the aleurone layer (AL) at the outer periphery. The fates of the cells that comprise these tissues are determined according to positional information; however, our understanding of the underlying molecular mechanisms remains limited. Here, we conducted a high-resolution spatiotemporal analysis of the rice endosperm transcriptome during early cellularization. In rice, endosperm cellularization proceeds in a concentric pattern from a primary alveolus cell layer, such that developmental progression can be defined by the number of cell layers. Using laser-capture microdissection to obtain precise tissue sections, transcriptomic changes were followed through five histologically defined stages of cellularization from the syncytial to 3-cell layer (3 L) stage. In addition, transcriptomes were compared between the inner and the outermost peripheral cell layers. Large differences in the transcriptomes between stages and between the inner and the peripheral cells were found. SE attributes were expressed at the alveolus-cell-layer stage but were preferentially activated in the inner cell layers that resulted from periclinal division of the alveolus cell layer. Similarly, AL attributes started to be expressed only after the 2 L stage and were localized to the outermost peripheral cell layer. These results indicate that the first periclinal division of the alveolus cell layer is asymmetric at the transcriptome level, and that the cell-fate-specifying positional cues and their perception system are already operating before the first periclinal division. Several genes related to epidermal identity (i.e., type IV homeodomain-leucine zipper genes and wax biosynthetic genes) were also found to be expressed at the syncytial stage, but their expression was localized to the outermost peripheral cell layer from the 2 L stage onward. We believe that our findings significantly enhance our knowledge of the mechanisms underlying cell fate specification in rice endosperm.
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Affiliation(s)
- Yoshinori Takafuji
- Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya, 464-8601, Japan
| | - Sae Shimizu-Sato
- National Institute of Genetics, 1111 Yata, Mishima, Shizuoka, 411-8540, Japan
| | - Kim Nhung Ta
- National Institute of Genetics, 1111 Yata, Mishima, Shizuoka, 411-8540, Japan
| | - Toshiya Suzuki
- National Institute of Genetics, 1111 Yata, Mishima, Shizuoka, 411-8540, Japan
- Department of Genetics, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), 1111 Yata, Mishima, Shizuoka, 411-8540, Japan
| | - Misuzu Nosaka-Takahashi
- National Institute of Genetics, 1111 Yata, Mishima, Shizuoka, 411-8540, Japan
- Department of Genetics, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), 1111 Yata, Mishima, Shizuoka, 411-8540, Japan
| | - Tetsuro Oiwa
- Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya, 464-8601, Japan
| | - Wakana Kimura
- Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya, 464-8601, Japan
| | - Hirokazu Katoh
- Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya, 464-8601, Japan
| | - Mao Fukai
- Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya, 464-8601, Japan
| | - Shin Takeda
- Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya, 464-8601, Japan.
| | - Yutaka Sato
- National Institute of Genetics, 1111 Yata, Mishima, Shizuoka, 411-8540, Japan.
- Department of Genetics, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), 1111 Yata, Mishima, Shizuoka, 411-8540, Japan.
| | - Tsukaho Hattori
- Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya, 464-8601, Japan.
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González-Thuillier I, Pellny TK, Tosi P, Mitchell RA, Haslam R, Shewry PR. Accumulation and deposition of triacylglycerols in the starchy endosperm of wheat grain. J Cereal Sci 2021; 98:103167. [PMID: 33897098 PMCID: PMC8047771 DOI: 10.1016/j.jcs.2021.103167] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2020] [Revised: 01/11/2021] [Accepted: 01/13/2021] [Indexed: 11/19/2022]
Abstract
A combination of lipidomics, transcriptomics and bioimaging has been used to study triacylglycerol synthesis and deposition in the developing starchy endosperm of wheat. The content of TAG increased between 14 and 34 days after anthesis, from 50 to 115 mg/100 g dry wt and from about 35 to 175 mg/100 g dry wt in two experiments. The major fatty acids were C16 (palmitic C16:0 and palmitoleic C16:1) and C18 (stearic C18:0, oleic C18:1, linoleic C18:2 and linolenic C18:3), with unsaturated fatty acids accounting for about 75-80% of the total throughout development. Linoleic acid (C18:2) was the major component at all stages and the proportion increased during development. Transcript profiling indicated that predominant route to TAG synthesis and oil accumulation is via the Kennedy pathway and diacylglycerol acyltransferase (DGAT) activity. Confocal microscopy of stained tissue sections showed that TAG accumulated in droplets which are associated with protein and concentrated in the starchy endosperm cells below the sub-aleurone cells. Transcripts encoding 16kd oleosins were also expressed, indicating that the oil droplets are in part stabilised by oleosin proteins.
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Affiliation(s)
| | - Till K. Pellny
- Rothamsted Research, Harpenden, Hertfordshire, AL5 2JQ, UK
| | - Paola Tosi
- School of Agriculture, Policy and Development, University of Reading, Whiteknights Campus, Early Gate, RG6 6AR, UK
| | | | - Richard Haslam
- Rothamsted Research, Harpenden, Hertfordshire, AL5 2JQ, UK
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Abstract
The starchy endosperm of the mature wheat grain comprises three major cell types, namely sub-aleurone cells, prismatic cells and central cells, which differ in their contents of functional components: gluten proteins, starch, cell wall polysaccharides (dietary fibre) and lipids. Gradients are established during grain development but may be modified during grain maturation and are affected by plant nutrition, particularly nitrogen application, and environmental factors. Although the molecular controls of their formation are unknown, the high content of protein and low content of starch of sub-aleurone cells, compared to the other starchy endosperm cells types, may result from differences in developmental programming related to the cells having a separate origin (from anticlinal division of the aleurone cells). The gradients within the grain may be reflected in differences in the compositions of mill streams, particularly those streams enriched in the central and outer cells of the starchy endosperm, respectively, allowing the production of specialist flours for specific end uses. The mature starchy endosperm of wheat comprises three cell types. These differ in their contents of functional components. These differences are reflected in the compositions of mill streams. These differences may affect functionality. Hence innovative milling can be used to prepare flours for special uses.
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Key Words
- A, arabinose
- AX, arabinoxylan
- AXOS, arabinoxylan oligosaccharide
- DP, degree of polymerisation
- DPA, days past anthesis
- Dietary fibre
- FTIR, Fourier transform infrared
- GL, galactolipid
- Gluten proteins
- HMW, high molecular weight
- LMW, low molecular weight
- Lipids
- NMR, nuclear magnetic resonance
- PL, phospholipid
- Polysaccharides
- SIMS, secondary ion mass spectrometry
- Starch
- Starchy endosperm
- TAG, triacylglycerol
- TDF, total dietary fibre
- WE, water-extractable
- WU, water-unextractable
- Wheat
- White flour
- X, xylose
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Affiliation(s)
- Peter R Shewry
- Plant Science Department, Rothamsted Research, Harpenden, Herts, AL5 2JQ, UK.,School of Agriculture, Policy and Development, University of Reading, Whiteknights Campus, Early Gate, RG6 6AR, Reading, UK
| | - Yongfang Wan
- Plant Science Department, Rothamsted Research, Harpenden, Herts, AL5 2JQ, UK
| | | | - Paola Tosi
- School of Agriculture, Policy and Development, University of Reading, Whiteknights Campus, Early Gate, RG6 6AR, Reading, UK
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Zhang M, Lv R, Yang W, Fu T, Liu B. Imprinted gene expression in maize starchy endosperm and aleurone tissues of reciprocal F1 hybrids at a defined developmental stage. Genes Genomics 2018; 40:99-107. [PMID: 29892900 DOI: 10.1007/s13258-017-0613-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2017] [Accepted: 09/10/2017] [Indexed: 10/18/2022]
Abstract
Imprinted gene expression in flowering plants predominantly occurs in the triploid endosperm of developing seed. However, endosperm is composed of distinct tissue types. For example, the maize (Zea mays) endosperm is constituted by two major tissues, starchy endosperm and aleurone. Previous studies in imprinted gene expression have generally assumed that the different tissues constituting endosperm would behavior the same, and hence have not examined them separately. Here, to examine parental-specific expression of imprinted genes in different parts of the seed, eight previously reported maize protein-coding imprinted genes were selected, and analyzed by cleaved amplified polymorphic sequence (CAPS) coupled with Sanger sequencing for transcripts from the various seed tissues collected at 18 days after pollination (DAP). The studied tissues included seed coat, embryo, starchy endosperm and aleurone, which were collected from a pair of reciprocal F1 hybrids produced by crossing inbred lines B73 and Mo17. Six of these eight analyzed imprinted genes showed the same imprinted expression pattern between the starchy endosperm and aleurone, but two showed imprinted expression only in the starchy endosperm. Comparison of the expression pattern of 20 selected imprinted genes in multiple seed tissues and vegetative tissues indicated that the majority (~ 75%) of these imprinted genes exhibited seed-specific or endosperm-specific expression. Our results also uncovered that imprinted genes have a high propensity to be alternatively spliced via intron retention in the developing embryo compared with the other tissues.
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Affiliation(s)
- Meishan Zhang
- Department of Agronomy, Jilin Agricultural University, Changchun, 130118, People's Republic of China.
| | - Ruili Lv
- Key Laboratory of Molecular Epigenetics of the Ministry of Education (MOE), Northeast Normal University, Changchun, 130024, People's Republic of China
| | - Wei Yang
- Department of Agronomy, Jilin Agricultural University, Changchun, 130118, People's Republic of China
| | - Tiansi Fu
- Key Laboratory of Molecular Epigenetics of the Ministry of Education (MOE), Northeast Normal University, Changchun, 130024, People's Republic of China
| | - Bao Liu
- Key Laboratory of Molecular Epigenetics of the Ministry of Education (MOE), Northeast Normal University, Changchun, 130024, People's Republic of China.
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Cu S, Collins HM, Betts NS, March TJ, Janusz A, Stewart DC, Skadhauge B, Eglinton J, Kyriacou B, Little A, Burton RA, Fincher GB. Water uptake in barley grain: Physiology; genetics and industrial applications. Plant Sci 2016; 242:260-269. [PMID: 26566843 DOI: 10.1016/j.plantsci.2015.08.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Revised: 08/08/2015] [Accepted: 08/13/2015] [Indexed: 06/05/2023]
Abstract
Water uptake by mature barley grains initiates germination and is the first stage in the malting process. Here we have investigated the effects of starchy endosperm cell wall thickness on water uptake, together with the effects of varying amounts of the wall polysaccharide, (1,3;1,4)-β-glucan. In the latter case, we examined mutant barley lines from a mutant library and transgenic barley lines in which the (1,3;1,4)-β-glucan synthase gene, HvCslF6, was down-regulated by RNA interference. Neither cell wall thickness nor the levels of grain (1,3;1,4)-β-glucan were significantly correlated with water uptake but are likely to influence modification during malting. However, when a barley mapping population was phenotyped for rate of water uptake into grain, quantitative trait locus (QTL) analysis identified specific regions of chromosomes 4H, 5H and 7H that accounted for approximately 17%, 18% and 11%, respectively, of the phenotypic variation. These data indicate that variation in water uptake rates by elite malting cultivars of barley is genetically controlled and a number of candidate genes that might control the trait were identified under the QTL. The genomics data raise the possibility that the genetic variation in water uptake rates might be exploited by breeders for the benefit of the malting and brewing industries.
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Affiliation(s)
- Suong Cu
- Australian Research Council Centre of Excellence in Plant Cell Walls, University of Adelaide, Waite Campus, Glen Osmond, SA 5064, Australia
| | - Helen M Collins
- Australian Research Council Centre of Excellence in Plant Cell Walls, University of Adelaide, Waite Campus, Glen Osmond, SA 5064, Australia
| | - Natalie S Betts
- Australian Research Council Centre of Excellence in Plant Cell Walls, University of Adelaide, Waite Campus, Glen Osmond, SA 5064, Australia
| | - Timothy J March
- School of Agriculture, Food and Wine, University of Adelaide, Waite Campus, Glen Osmond, SA 5064, Australia
| | - Agnieszka Janusz
- Cargill Malt, Cargill, 65 Magill Road, Stepney SA 5069, Australia
| | - Doug C Stewart
- Coopers Brewery, 461 South Rd, Regency Park SA 5010, Australia
| | - Birgitte Skadhauge
- Carlsberg Group Research, Gamle Carlsberg Vej 10, 1799 Copenhagen V, Denmark
| | - Jason Eglinton
- School of Agriculture, Food and Wine, University of Adelaide, Waite Campus, Glen Osmond, SA 5064, Australia
| | - Bianca Kyriacou
- Australian Research Council Centre of Excellence in Plant Cell Walls, University of Adelaide, Waite Campus, Glen Osmond, SA 5064, Australia
| | - Alan Little
- Australian Research Council Centre of Excellence in Plant Cell Walls, University of Adelaide, Waite Campus, Glen Osmond, SA 5064, Australia
| | - Rachel A Burton
- Australian Research Council Centre of Excellence in Plant Cell Walls, University of Adelaide, Waite Campus, Glen Osmond, SA 5064, Australia
| | - Geoffrey B Fincher
- Australian Research Council Centre of Excellence in Plant Cell Walls, University of Adelaide, Waite Campus, Glen Osmond, SA 5064, Australia.
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