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Efficient Accumulation of Amylopectin and Its Molecular Mechanism in the Submerged Duckweed Mutant

Large-scale use of fossil fuels has brought about increasingly serious problems of environmental pollution, development and utilization of renewable energy is one of the effective solutions. Duckweed has the advantages of fast growth, high starch content and no occupation of arable land, so it is a...

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Autores principales: Liu, Yu, Yan, Ruiting, Li, Zonghao, Fan, Shusheng, Li, Chuantong, Yu, Ruikang, Liu, Huaqing, Kong, Yingzhen, Li, Haimei, Tang, Xianfeng, Zhou, Gongke
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2023
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9917893/
https://www.ncbi.nlm.nih.gov/pubmed/36769258
http://dx.doi.org/10.3390/ijms24032934
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author Liu, Yu
Yan, Ruiting
Li, Zonghao
Fan, Shusheng
Li, Chuantong
Yu, Ruikang
Liu, Huaqing
Kong, Yingzhen
Li, Haimei
Tang, Xianfeng
Zhou, Gongke
author_facet Liu, Yu
Yan, Ruiting
Li, Zonghao
Fan, Shusheng
Li, Chuantong
Yu, Ruikang
Liu, Huaqing
Kong, Yingzhen
Li, Haimei
Tang, Xianfeng
Zhou, Gongke
author_sort Liu, Yu
collection PubMed
description Large-scale use of fossil fuels has brought about increasingly serious problems of environmental pollution, development and utilization of renewable energy is one of the effective solutions. Duckweed has the advantages of fast growth, high starch content and no occupation of arable land, so it is a promising starchy energy plant. A new submerged duckweed mutant (sub-1) with abundant starch accumulation was obtained, whose content of amylopectin accounts for 84.04% of the starch granules. Compared with the wild type (Lemna aequinoctialis), the branching degree of starch in sub-1 mutant was significantly increased by 19.6%. Chain length DP 6–12, DP 25–36 and DP > 36 of amylopectin significantly decreased, while chain length DP 13–24 significantly increased. Average chain length of wild-type and sub-1 mutant starches were greater than DP 22. Moreover, the crystal structure and physical properties of starch have changed markedly in sub-1 mutant. For example, the starch crystallinity of sub-1 mutant was only 8.94%, while that of wild-type was 22.3%. Compared with wild type, water solubility of starch was significantly reduced by 29.42%, whereas swelling power significantly increased by 97.07% in sub-1 mutant. In order to further analyze the molecular mechanism of efficient accumulation of amylopectin in sub-1 mutant, metabolome and transcriptome were performed. The results showed that glucose accumulated in sub-1 mutant, then degradation of starch to glucose mainly depends on α-amylase. At night, the down-regulated β-amylase gene resulted in the inhibition of starch degradation. The starch and sucrose metabolism pathways were significantly enriched. Up-regulated expression of SUS, AGPase2, AGPase3, PYG, GPI and GYS provide sufficient substrate for starch synthesis in sub-1 mutant. From the 0H to 16H light treatment, granule-bound starch synthase (GBSS1) gene was inhibited, on the contrary, the starch branching enzyme (SBE) gene was induced. Differential expression of GBSS1 and SBE may be an important reason for the decrease ratio of amylose/amylopectin in sub-1 mutant. Taken together, our results indicated that the sub-1 mutant can accumulate the amylopectin efficiently, potentially through altering the differential expression of AGPase, GBSS1, SBE, and BAM. This study also provides theoretical guidance for creating crop germplasm with high amylopectin by means of synthetic biology in the future.
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spelling pubmed-99178932023-02-11 Efficient Accumulation of Amylopectin and Its Molecular Mechanism in the Submerged Duckweed Mutant Liu, Yu Yan, Ruiting Li, Zonghao Fan, Shusheng Li, Chuantong Yu, Ruikang Liu, Huaqing Kong, Yingzhen Li, Haimei Tang, Xianfeng Zhou, Gongke Int J Mol Sci Article Large-scale use of fossil fuels has brought about increasingly serious problems of environmental pollution, development and utilization of renewable energy is one of the effective solutions. Duckweed has the advantages of fast growth, high starch content and no occupation of arable land, so it is a promising starchy energy plant. A new submerged duckweed mutant (sub-1) with abundant starch accumulation was obtained, whose content of amylopectin accounts for 84.04% of the starch granules. Compared with the wild type (Lemna aequinoctialis), the branching degree of starch in sub-1 mutant was significantly increased by 19.6%. Chain length DP 6–12, DP 25–36 and DP > 36 of amylopectin significantly decreased, while chain length DP 13–24 significantly increased. Average chain length of wild-type and sub-1 mutant starches were greater than DP 22. Moreover, the crystal structure and physical properties of starch have changed markedly in sub-1 mutant. For example, the starch crystallinity of sub-1 mutant was only 8.94%, while that of wild-type was 22.3%. Compared with wild type, water solubility of starch was significantly reduced by 29.42%, whereas swelling power significantly increased by 97.07% in sub-1 mutant. In order to further analyze the molecular mechanism of efficient accumulation of amylopectin in sub-1 mutant, metabolome and transcriptome were performed. The results showed that glucose accumulated in sub-1 mutant, then degradation of starch to glucose mainly depends on α-amylase. At night, the down-regulated β-amylase gene resulted in the inhibition of starch degradation. The starch and sucrose metabolism pathways were significantly enriched. Up-regulated expression of SUS, AGPase2, AGPase3, PYG, GPI and GYS provide sufficient substrate for starch synthesis in sub-1 mutant. From the 0H to 16H light treatment, granule-bound starch synthase (GBSS1) gene was inhibited, on the contrary, the starch branching enzyme (SBE) gene was induced. Differential expression of GBSS1 and SBE may be an important reason for the decrease ratio of amylose/amylopectin in sub-1 mutant. Taken together, our results indicated that the sub-1 mutant can accumulate the amylopectin efficiently, potentially through altering the differential expression of AGPase, GBSS1, SBE, and BAM. This study also provides theoretical guidance for creating crop germplasm with high amylopectin by means of synthetic biology in the future. MDPI 2023-02-02 /pmc/articles/PMC9917893/ /pubmed/36769258 http://dx.doi.org/10.3390/ijms24032934 Text en © 2023 by the authors. https://creativecommons.org/licenses/by/4.0/Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Liu, Yu
Yan, Ruiting
Li, Zonghao
Fan, Shusheng
Li, Chuantong
Yu, Ruikang
Liu, Huaqing
Kong, Yingzhen
Li, Haimei
Tang, Xianfeng
Zhou, Gongke
Efficient Accumulation of Amylopectin and Its Molecular Mechanism in the Submerged Duckweed Mutant
title Efficient Accumulation of Amylopectin and Its Molecular Mechanism in the Submerged Duckweed Mutant
title_full Efficient Accumulation of Amylopectin and Its Molecular Mechanism in the Submerged Duckweed Mutant
title_fullStr Efficient Accumulation of Amylopectin and Its Molecular Mechanism in the Submerged Duckweed Mutant
title_full_unstemmed Efficient Accumulation of Amylopectin and Its Molecular Mechanism in the Submerged Duckweed Mutant
title_short Efficient Accumulation of Amylopectin and Its Molecular Mechanism in the Submerged Duckweed Mutant
title_sort efficient accumulation of amylopectin and its molecular mechanism in the submerged duckweed mutant
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9917893/
https://www.ncbi.nlm.nih.gov/pubmed/36769258
http://dx.doi.org/10.3390/ijms24032934
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