Limits...
Allelic effects on starch structure and properties of six starch biosynthetic genes in a rice recombinant inbred line population.

Luo J, Jobling SA, Millar A, Morell MK, Li Z - Rice (N Y) (2015)

Bottom Line: Both major alleles (Wxi and SSIIaj) reduced peak viscosity (PV), onset, peak and end gelatinization temperatures (GTs) of amylopectin, and increased amylose-lipid complex dissociation enthalpy compared with their counterpart-alleles, respectively.SBEIIai and SBEIIbj decreased PV, whereas SSIi and SBEIIbj decreased FV.SBEIi reduced setback viscosity and gelatinization enthalpy.

View Article: PubMed Central - PubMed

Affiliation: CSIRO Agriculture Flagship, GPO Box 1600, Canberra, ACT 2601 Australia ; College of Medicine, Biology and Environment, Australian National University, Canberra, ACT 0200 Australia.

ABSTRACT

Background: The genetic diversity of six starch biosynthetic genes (Wx, SSI, SSIIa, SBEI, SBEIIa and SBEIIb) in indica and japonica rices opens an opportunity to produce a new variety with more favourable grain starch quality. However, there is limited information about the effects of these six gene allele combinations on starch structure and properties. A recombinant inbred line population from a cross between indica and japonica varieties offers opportunities to combine specific alleles of the six genes.

Results: The allelic (indica vs japonica) effects of six starch biosynthetic genes on starch structure, functional properties, and abundance of granule bound proteins in rice grains were investigated in a common genetic background using a recombinant inbred line population. The indica Wx (Wxi) allele played a major role while indica SSI (SSIi), japonica SSIIa (SSIIaj) and indica SBEI (SBEIi) alleles had minor roles on the increase of amylose content. SSIIaj and japonica SBEIIb (SBEIIbj) alleles had a major and a minor role on high ratio of ∑DP ≤ 10 to ∑DP ≤ 24 fractions (RCL10/24), respectively. Both major alleles (Wxi and SSIIaj) reduced peak viscosity (PV), onset, peak and end gelatinization temperatures (GTs) of amylopectin, and increased amylose-lipid complex dissociation enthalpy compared with their counterpart-alleles, respectively. SBEIIai and SBEIIbj decreased PV, whereas SSIi and SBEIIbj decreased FV. SBEIi reduced setback viscosity and gelatinization enthalpy. RCL10/24 of chain length distribution in amylopectin is negatively correlated with PV and BD of paste property and GTs of thermal properties. We also report RILs with superior starch properties combining Wxi, SSIj, SSIIaj, SBEIi and SBEIIbj alleles. Additionally, a clear relation is drawn to starch biosynthetic gene alleles, starch structure, properties, and abundance of granule bound starch biosynthetic enzymes inside starch granules.

Conclusions: Rice Wxi and SSIIaj alleles play major roles, while SSIi, SBEIi, SBEIIai and SBEIIbj alleles have minor roles in the determination of starch properties between indica and japonica rice through starch structural modification. The combination of these alleles is a key factor for starch quality improvement in rice breeding programs. RCL10/24 value is critical for starch structure and property determination.

No MeSH data available.


Related in: MedlinePlus

Generation of RILs for each of two alleles of six starch synthetic genes. Six genes for genotyping of alleles are Wx, SSI, SSIIa, SBEI, SBEIIa, SBEIIb. Parental lines are IR64 and Nipponbare. The arrows indicate descendants of each line. The numbers with slash line indicate the name of each line. The numbers following ‘F’ imply the generation on the left of the figure. The italic letters followed by ‘i’ or ‘j’ (indicating indica and japonica, respectively) indicate alleles of the RILs.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4385112&req=5

Fig1: Generation of RILs for each of two alleles of six starch synthetic genes. Six genes for genotyping of alleles are Wx, SSI, SSIIa, SBEI, SBEIIa, SBEIIb. Parental lines are IR64 and Nipponbare. The arrows indicate descendants of each line. The numbers with slash line indicate the name of each line. The numbers following ‘F’ imply the generation on the left of the figure. The italic letters followed by ‘i’ or ‘j’ (indicating indica and japonica, respectively) indicate alleles of the RILs.

Mentions: Six allele groups were selected from recombinant inbred lines corresponding to the 6 major starch synthetic enzyme genes, and parental lines (IR64 and Nipponbare) differing in their alleles (i vs j) for each of the 6 genes. Thus we segregated the RILs into six allele groups according to the allele combinations (Figure 1) to analyse the effects of i vs j alleles of different starch biosynthetic genes on starch structure and properties. The allele types of these six genes of each RIL are described in Table 1, and are designated as follows: line 3-14-12 and 3-14-13 as Wxi and Wxj; line 3-5-15-11 and 3-6-20 as SSIi and SSIj; line 3-6-9 and 3-6-1 as SSIIai and SSIIaj; line 3-5-1-2 and 3-5-1-8 as SBEIi and SBEIj; line 3-6-20 and 3-6-9 as SBEIIai and SBEIIaj; and line 3-5-2-2 and 3-5-2-1 as SBEIIbi and SBEIIbj. Meanwhile, we also separated RILs in Wxi and Wxj allele groups in some of the following analyses, because Wx alleles were well known in determining various starch characteristics.Figure 1


Allelic effects on starch structure and properties of six starch biosynthetic genes in a rice recombinant inbred line population.

Luo J, Jobling SA, Millar A, Morell MK, Li Z - Rice (N Y) (2015)

Generation of RILs for each of two alleles of six starch synthetic genes. Six genes for genotyping of alleles are Wx, SSI, SSIIa, SBEI, SBEIIa, SBEIIb. Parental lines are IR64 and Nipponbare. The arrows indicate descendants of each line. The numbers with slash line indicate the name of each line. The numbers following ‘F’ imply the generation on the left of the figure. The italic letters followed by ‘i’ or ‘j’ (indicating indica and japonica, respectively) indicate alleles of the RILs.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4385112&req=5

Fig1: Generation of RILs for each of two alleles of six starch synthetic genes. Six genes for genotyping of alleles are Wx, SSI, SSIIa, SBEI, SBEIIa, SBEIIb. Parental lines are IR64 and Nipponbare. The arrows indicate descendants of each line. The numbers with slash line indicate the name of each line. The numbers following ‘F’ imply the generation on the left of the figure. The italic letters followed by ‘i’ or ‘j’ (indicating indica and japonica, respectively) indicate alleles of the RILs.
Mentions: Six allele groups were selected from recombinant inbred lines corresponding to the 6 major starch synthetic enzyme genes, and parental lines (IR64 and Nipponbare) differing in their alleles (i vs j) for each of the 6 genes. Thus we segregated the RILs into six allele groups according to the allele combinations (Figure 1) to analyse the effects of i vs j alleles of different starch biosynthetic genes on starch structure and properties. The allele types of these six genes of each RIL are described in Table 1, and are designated as follows: line 3-14-12 and 3-14-13 as Wxi and Wxj; line 3-5-15-11 and 3-6-20 as SSIi and SSIj; line 3-6-9 and 3-6-1 as SSIIai and SSIIaj; line 3-5-1-2 and 3-5-1-8 as SBEIi and SBEIj; line 3-6-20 and 3-6-9 as SBEIIai and SBEIIaj; and line 3-5-2-2 and 3-5-2-1 as SBEIIbi and SBEIIbj. Meanwhile, we also separated RILs in Wxi and Wxj allele groups in some of the following analyses, because Wx alleles were well known in determining various starch characteristics.Figure 1

Bottom Line: Both major alleles (Wxi and SSIIaj) reduced peak viscosity (PV), onset, peak and end gelatinization temperatures (GTs) of amylopectin, and increased amylose-lipid complex dissociation enthalpy compared with their counterpart-alleles, respectively.SBEIIai and SBEIIbj decreased PV, whereas SSIi and SBEIIbj decreased FV.SBEIi reduced setback viscosity and gelatinization enthalpy.

View Article: PubMed Central - PubMed

Affiliation: CSIRO Agriculture Flagship, GPO Box 1600, Canberra, ACT 2601 Australia ; College of Medicine, Biology and Environment, Australian National University, Canberra, ACT 0200 Australia.

ABSTRACT

Background: The genetic diversity of six starch biosynthetic genes (Wx, SSI, SSIIa, SBEI, SBEIIa and SBEIIb) in indica and japonica rices opens an opportunity to produce a new variety with more favourable grain starch quality. However, there is limited information about the effects of these six gene allele combinations on starch structure and properties. A recombinant inbred line population from a cross between indica and japonica varieties offers opportunities to combine specific alleles of the six genes.

Results: The allelic (indica vs japonica) effects of six starch biosynthetic genes on starch structure, functional properties, and abundance of granule bound proteins in rice grains were investigated in a common genetic background using a recombinant inbred line population. The indica Wx (Wxi) allele played a major role while indica SSI (SSIi), japonica SSIIa (SSIIaj) and indica SBEI (SBEIi) alleles had minor roles on the increase of amylose content. SSIIaj and japonica SBEIIb (SBEIIbj) alleles had a major and a minor role on high ratio of ∑DP ≤ 10 to ∑DP ≤ 24 fractions (RCL10/24), respectively. Both major alleles (Wxi and SSIIaj) reduced peak viscosity (PV), onset, peak and end gelatinization temperatures (GTs) of amylopectin, and increased amylose-lipid complex dissociation enthalpy compared with their counterpart-alleles, respectively. SBEIIai and SBEIIbj decreased PV, whereas SSIi and SBEIIbj decreased FV. SBEIi reduced setback viscosity and gelatinization enthalpy. RCL10/24 of chain length distribution in amylopectin is negatively correlated with PV and BD of paste property and GTs of thermal properties. We also report RILs with superior starch properties combining Wxi, SSIj, SSIIaj, SBEIi and SBEIIbj alleles. Additionally, a clear relation is drawn to starch biosynthetic gene alleles, starch structure, properties, and abundance of granule bound starch biosynthetic enzymes inside starch granules.

Conclusions: Rice Wxi and SSIIaj alleles play major roles, while SSIi, SBEIi, SBEIIai and SBEIIbj alleles have minor roles in the determination of starch properties between indica and japonica rice through starch structural modification. The combination of these alleles is a key factor for starch quality improvement in rice breeding programs. RCL10/24 value is critical for starch structure and property determination.

No MeSH data available.


Related in: MedlinePlus