Sugary Endosperm is Modulated by Starch Branching Enzyme IIa in Rice (Oryza sativa L.)

Lee, Yunjoo; Choi, Mansoo; Lee, Gileung; Jang, Su; Yoon, Min-Ho; Kim, Backki; Piao, Rihua; Woo, Mi-Ok; Chin, Joong Hyoun; Koh, Hee‐Jong

doi:10.1186/s12284-017-0172-3

Cited by 22 publications

(18 citation statements)

References 38 publications

(59 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It is thought to be involved in the initiation step of starch biosynthesis in the rice endosperm, although Pho1 can also function to degrade glucan (Satoh et al, 2008). In addition to the above-mentioned starch biosynthetic isozymes, SSIVb (Toyosawa et al, 2016), BEIIa (Satoh et al, 2003; Lee et al, 2017), and the disproportionating enzyme (EC 2.4.1.25) (Dong et al, 2015) are also involved in amylopectin biosynthesis in the rice endosperm.…”

Section: Introductionmentioning

confidence: 99%

Rice Mutants Lacking Starch Synthase I or Branching Enzyme IIb Activity Altered Starch Biosynthetic Protein Complexes

et al. 2018

View full text Add to dashboard Cite

Amylopectin, the major component of starch, is synthesized by synergistic activity of multiple isozymes of starch synthases (SSs) and branching enzymes (BEs). The frequency and length of amylopectin branches determine the functionality of starch. In the rice endosperm, BEIIb generates short side chains of amylopectin and SSI elongates those branches, which can be further elongated by SSIIa. Absence of these enzymes greatly affects amylopectin structure. SSI, SSIIa, and BEIIb associate with each other and with other starch biosynthetic enzymes although SSIIa is low activity in japonica rice. The aim of the current study was to understand how the activity of starch biosynthetic enzyme complexes is compensated in the absence of SSI or BEIIb, and whether the compensatory effects are different in the absence of BEIIb or in the presence of inactive BEIIb. Interactions between starch biosynthetic enzymes were analyzed using one ss1 null mutant and two be2b japonica rice mutants (a mutant producing inactive BEIIb and a mutant that did not produce BEIIb). Soluble proteins extracted from the developing rice seeds were separated by gel filtration chromatography. In the absence of BEIIb activity, BEIIa was eluted in a broad molecular weight range (60–700 kDa). BEIIa in the wild-type was eluted with a mass below 300 kDa. Further, majority of inactive BEIIb co-eluted with SSI, SSIIa, and BEI, in a mass fraction over 700 kDa, whereas only small amounts of these isozymes were found in the wild-type. Compared with the be2b lines, the ss1 mutant showed subtle differences in protein profiles, but the amounts of SSIIa, SSIVb, and BEI in the over-700–kDa fraction were elevated. Immunoprecipitation revealed reduced association of SSIIa and BEIIb in the ss1 mutant, while the association of BEIIb with SSI, SSIIa, SSIVb, BEI, and BEIIa were more pronounced in the be2b mutant that produced inactive BEIIb enzyme. Mass spectrometry and western blotting revealed that SSI, SSIIa, SSIIIa, BEI, BEIIa, starch phosphorylase 1, and pullulanase were bound to the starch granules in the be2b mutants, but not in the wild-type and ss1 mutant. These results will aid the understanding of the mechanism of amylopectin biosynthesis.

show abstract

Section: Introductionmentioning

confidence: 99%

Rice Mutants Lacking Starch Synthase I or Branching Enzyme IIb Activity Altered Starch Biosynthetic Protein Complexes

et al. 2018

View full text Add to dashboard Cite

show abstract

“…A loss-of-function mutation of the gene encoding DBE results in a sugary phenotype in which endosperm starch is completely replaced by phytoglycogen [52,53]. Mutant sug-h, which is defective in OsISA1 and OsBEIIa, exhibits a severely disrupted amylopectin structure [54].…”

Section: Discussionmentioning

confidence: 99%

A New SNP in Rice Gene Encoding Pyruvate Phosphate Dikinase (PPDK) Associated with Floury Endosperm

Wang

Ham

et al. 2020

Genes

View full text Add to dashboard Cite

Rice varieties with suitable flour-making qualities are required to promote the rice processed-food industry and to boost rice consumption. A rice mutation, Namil(SA)-flo1, produces grains with floury endosperm. Overall, grains with low grain hardness, low starch damage, and fine particle size are more suitable for use in flour processing grains with waxy, dull endosperm with normal grain hardness and a high amylose content. In this study, fine mapping found a C to T single nucleotide polymorphism (SNP) in exon 2 of the gene encoding cytosolic pyruvate phosphate dikinase (cyOsPPDK). The SNP resulted in a change of serine to phenylalanine acid at amino acid position 101. The gene was named FLOURY ENDOSPERM 4-5 (FLO4-5). Co-segregation analysis with the developed cleaved amplified polymorphic sequence (CAPS) markers revealed co-segregation between the floury phenotype and the flo4-5. This CAPS marker could be applied directly for marker-assisted selection. Real-time RT-PCR experiments revealed that PPDK was expressed at considerably higher levels in the flo4-5 mutant than in the wild type during the grain filling stage. Plastid ADP-glucose pyrophosphorylase small subunit (AGPS2a and AGPS2b) and soluble starch synthase (SSIIb and SSIIc) also exhibited enhanced expression in the flo4-5 mutant.

show abstract

“…A study on the kidney bean (Phaseolus vulgaris) mutant pvsbe2 suggested that SBEII activity is important for both amylopectin biosynthesis and maturation during the middle and late stages of seed development 22 . Further, the expression of OsSBEIIa was found to regulate the sugary endosperm trait during development and maturity in the Sugary Endosperm rice mutant 23 . In maize, SBEIIadefective mutants exhibit a leaf-senescence phenotype as the result of the reduction in the proportion of branched starch 24 .…”

Section: Introductionmentioning

confidence: 95%

Molecular identification of the key starch branching enzyme-encoding gene SBE2.3 and its interacting transcription factors in banana fruits

et al. 2020

View full text Add to dashboard Cite

Starch branching enzyme (SBE) has rarely been studied in common starchy banana fruits. For the first time, we report here the molecular characterization of seven SBE (MaSBE) and six SBE (MbSBE) genes in the banana A-and B-genomes, respectively, which could be classified into three distinct subfamilies according to genome-wide identification. Systematic transcriptomic analysis revealed that six MaSBEs and six MbSBEs were expressed in the developing banana fruits of two different genotypes, BaXi Jiao (BX, AAA) and Fen Jiao (FJ, AAB), among which MaSBE2.3 and MbSBE2.3 were highly expressed. Transient silencing of MaSBE2.3 expression in banana fruit discs led to a significant decrease in its transcription, which coincides with significant reductions in total starch and amylopectin contents compared to those of empty vector controls. The suggested functional role of MaSBE2.3 in banana fruit development was corroborated by its transient overexpression in banana fruit discs, which led to significant enhancements in total starch and amylopectin contents. A number of transcription factors, including three auxin response factors (ARF2/12/24) and two MYBs (MYB3/308), that interact with the MaSBE2.3 promoter were identified by yeast one-hybrid library assays. Among these ARFs and MYBs, MaARF2/MaMYB308 and MaARF12/MaARF24/MaMYB3 were demonstrated via a luciferase reporter system to upregulate and downregulate the expression of MaSBE2.3, respectively.

show abstract

Sugary Endosperm is Modulated by Starch Branching Enzyme IIa in Rice (Oryza sativa L.)

Cited by 22 publications

References 38 publications

Rice Mutants Lacking Starch Synthase I or Branching Enzyme IIb Activity Altered Starch Biosynthetic Protein Complexes

Rice Mutants Lacking Starch Synthase I or Branching Enzyme IIb Activity Altered Starch Biosynthetic Protein Complexes

A New SNP in Rice Gene Encoding Pyruvate Phosphate Dikinase (PPDK) Associated with Floury Endosperm

Molecular identification of the key starch branching enzyme-encoding gene SBE2.3 and its interacting transcription factors in banana fruits

Contact Info

Product

Resources

About