Inactivation of rice starch branching enzyme IIb triggers broad and unexpected changes in metabolism by transcriptional reprogramming. / Baysal, Can ; He, Wenshu; Drapal, Margit; Villorbina, Gemma ; Medina, Vicente ; Capell, Teresa; Khush, Gurdev ; Zhu, Changfu; Fraser, Paul; Christou, Paul.

In: Proceedings of the National Academy of Sciences of the United States of America, Vol. 117, No. 42, 20.10.2020, p. 26503-26512.

Research output: Contribution to journalArticlepeer-review

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Inactivation of rice starch branching enzyme IIb triggers broad and unexpected changes in metabolism by transcriptional reprogramming. / Baysal, Can ; He, Wenshu; Drapal, Margit; Villorbina, Gemma ; Medina, Vicente ; Capell, Teresa; Khush, Gurdev ; Zhu, Changfu; Fraser, Paul; Christou, Paul.

In: Proceedings of the National Academy of Sciences of the United States of America, Vol. 117, No. 42, 20.10.2020, p. 26503-26512.

Research output: Contribution to journalArticlepeer-review

Harvard

Baysal, C, He, W, Drapal, M, Villorbina, G, Medina, V, Capell, T, Khush, G, Zhu, C, Fraser, P & Christou, P 2020, 'Inactivation of rice starch branching enzyme IIb triggers broad and unexpected changes in metabolism by transcriptional reprogramming', Proceedings of the National Academy of Sciences of the United States of America, vol. 117, no. 42, pp. 26503-26512. https://doi.org/10.1073/pnas.2014860117

APA

Baysal, C., He, W., Drapal, M., Villorbina, G., Medina, V., Capell, T., Khush, G., Zhu, C., Fraser, P., & Christou, P. (2020). Inactivation of rice starch branching enzyme IIb triggers broad and unexpected changes in metabolism by transcriptional reprogramming. Proceedings of the National Academy of Sciences of the United States of America, 117(42), 26503-26512. https://doi.org/10.1073/pnas.2014860117

Vancouver

Baysal C, He W, Drapal M, Villorbina G, Medina V, Capell T et al. Inactivation of rice starch branching enzyme IIb triggers broad and unexpected changes in metabolism by transcriptional reprogramming. Proceedings of the National Academy of Sciences of the United States of America. 2020 Oct 20;117(42):26503-26512. https://doi.org/10.1073/pnas.2014860117

Author

Baysal, Can ; He, Wenshu ; Drapal, Margit ; Villorbina, Gemma ; Medina, Vicente ; Capell, Teresa ; Khush, Gurdev ; Zhu, Changfu ; Fraser, Paul ; Christou, Paul. / Inactivation of rice starch branching enzyme IIb triggers broad and unexpected changes in metabolism by transcriptional reprogramming. In: Proceedings of the National Academy of Sciences of the United States of America. 2020 ; Vol. 117, No. 42. pp. 26503-26512.

BibTeX

@article{e037fb4c0b4c46048f058249d19bebdb,
title = "Inactivation of rice starch branching enzyme IIb triggers broad and unexpected changes in metabolism by transcriptional reprogramming",
abstract = "Starch properties can be modified by mutating genes responsible for the synthesis of amylose and amylopectin in the endosperm. However, little is known about the effects of such targeted modifications on the overall starch biosynthesis pathway and broader metabolism. Here we investigated the effects of mutating the OsSBEIIb gene encoding starch branching enzyme IIb, which is required for amylopectin synthesis in the endosperm. As anticipated, homozygous mutant plants in which OsSBEIIb was completely inactivated by abolishing the catalytic center and C-terminal regulatory domain produced opaque seeds with abnormal starch grains, depleted starch reserves (~26% below wild-type levels). Amylose content in the mutant increased from 19.6 to 27.4% and resistant starch (RS) content increased from 0.2% to 17.2%. Many genes encoding isoforms of AGPase, soluble starch synthase and other starch branching enzymes were upregulated, either in their native tissues or in an ectopic manner, whereas genes encoding granule bound starch synthase debranching enzymes, pullulanases and starch phosphorylases were largely downregulated. There was a general increase in the accumulation of sugars, fatty acids, amino acids and phytosterols in the mutant endosperm, suggesting that intermediates in the starch biosynthesis pathway increased flux through spillover pathways causing a profound impact on the accumulation of multiple primary and secondary metabolites. Our results provide insight into the broader implications of perturbing starch metabolism in rice endosperm and its impact on the whole plant, which will make it easier to predict the effect of metabolic engineering in cereals for nutritional improvement or the production of valuable metabolites.",
keywords = "endosperm, high-amylose rice, metabolomics, starch biosynthesis, transcriptomics",
author = "Can Baysal and Wenshu He and Margit Drapal and Gemma Villorbina and Vicente Medina and Teresa Capell and Gurdev Khush and Changfu Zhu and Paul Fraser and Paul Christou",
year = "2020",
month = oct,
day = "20",
doi = "10.1073/pnas.2014860117",
language = "English",
volume = "117",
pages = "26503--26512",
journal = " Proceedings of the National Academy of Sciences of the United States of America",
issn = "0027-8424",
publisher = "National Academy of Sciences",
number = "42",

}

RIS

TY - JOUR

T1 - Inactivation of rice starch branching enzyme IIb triggers broad and unexpected changes in metabolism by transcriptional reprogramming

AU - Baysal, Can

AU - He, Wenshu

AU - Drapal, Margit

AU - Villorbina, Gemma

AU - Medina, Vicente

AU - Capell, Teresa

AU - Khush, Gurdev

AU - Zhu, Changfu

AU - Fraser, Paul

AU - Christou, Paul

PY - 2020/10/20

Y1 - 2020/10/20

N2 - Starch properties can be modified by mutating genes responsible for the synthesis of amylose and amylopectin in the endosperm. However, little is known about the effects of such targeted modifications on the overall starch biosynthesis pathway and broader metabolism. Here we investigated the effects of mutating the OsSBEIIb gene encoding starch branching enzyme IIb, which is required for amylopectin synthesis in the endosperm. As anticipated, homozygous mutant plants in which OsSBEIIb was completely inactivated by abolishing the catalytic center and C-terminal regulatory domain produced opaque seeds with abnormal starch grains, depleted starch reserves (~26% below wild-type levels). Amylose content in the mutant increased from 19.6 to 27.4% and resistant starch (RS) content increased from 0.2% to 17.2%. Many genes encoding isoforms of AGPase, soluble starch synthase and other starch branching enzymes were upregulated, either in their native tissues or in an ectopic manner, whereas genes encoding granule bound starch synthase debranching enzymes, pullulanases and starch phosphorylases were largely downregulated. There was a general increase in the accumulation of sugars, fatty acids, amino acids and phytosterols in the mutant endosperm, suggesting that intermediates in the starch biosynthesis pathway increased flux through spillover pathways causing a profound impact on the accumulation of multiple primary and secondary metabolites. Our results provide insight into the broader implications of perturbing starch metabolism in rice endosperm and its impact on the whole plant, which will make it easier to predict the effect of metabolic engineering in cereals for nutritional improvement or the production of valuable metabolites.

AB - Starch properties can be modified by mutating genes responsible for the synthesis of amylose and amylopectin in the endosperm. However, little is known about the effects of such targeted modifications on the overall starch biosynthesis pathway and broader metabolism. Here we investigated the effects of mutating the OsSBEIIb gene encoding starch branching enzyme IIb, which is required for amylopectin synthesis in the endosperm. As anticipated, homozygous mutant plants in which OsSBEIIb was completely inactivated by abolishing the catalytic center and C-terminal regulatory domain produced opaque seeds with abnormal starch grains, depleted starch reserves (~26% below wild-type levels). Amylose content in the mutant increased from 19.6 to 27.4% and resistant starch (RS) content increased from 0.2% to 17.2%. Many genes encoding isoforms of AGPase, soluble starch synthase and other starch branching enzymes were upregulated, either in their native tissues or in an ectopic manner, whereas genes encoding granule bound starch synthase debranching enzymes, pullulanases and starch phosphorylases were largely downregulated. There was a general increase in the accumulation of sugars, fatty acids, amino acids and phytosterols in the mutant endosperm, suggesting that intermediates in the starch biosynthesis pathway increased flux through spillover pathways causing a profound impact on the accumulation of multiple primary and secondary metabolites. Our results provide insight into the broader implications of perturbing starch metabolism in rice endosperm and its impact on the whole plant, which will make it easier to predict the effect of metabolic engineering in cereals for nutritional improvement or the production of valuable metabolites.

KW - endosperm, high-amylose rice, metabolomics, starch biosynthesis, transcriptomics

U2 - 10.1073/pnas.2014860117

DO - 10.1073/pnas.2014860117

M3 - Article

VL - 117

SP - 26503

EP - 26512

JO - Proceedings of the National Academy of Sciences of the United States of America

JF - Proceedings of the National Academy of Sciences of the United States of America

SN - 0027-8424

IS - 42

ER -