scholarly journals Haplotype Variations and Evolutionary Analysis of the Granule-Bound Starch Synthase I Gene in the Korean World Rice Collection

2021 ◽  
Vol 12 ◽  
Author(s):  
Thant Zin Maung ◽  
Ji-Min Yoo ◽  
Sang-Ho Chu ◽  
Kyu-Won Kim ◽  
Ill-Min Chung ◽  
...  

Granule-bound starch synthase I (GBSSI) is responsible for Waxy gene encoding the, which is involved in the amylose synthesis step of starch biosynthesis. We investigated the genotypic and haplotypic variations of GBSSI (Os06g0133000) gene, including its evolutionary relatedness in the nucleotide sequence level using single-nucleotide polymorphisms (SNPs), indels, and structural variations (SVs) from 475 Korean World Rice Collection (KRICE_CORE), which comprised 54 wild rice and 421 cultivated represented by 6 ecotypes (temperate japonica, indica, tropical japonica, aus, aromatic, and admixture) or in another way by 3 varietal types (landrace, weedy, and bred). The results revealed that 27 of 59 haplotypes indicated a total of 12 functional SNPs (fSNPs), identifying 9 novel fSNPs. According to the identified novel fSNPs, we classified the entire rice collection into three groups: cultivated, wild, and mixed (cultivated and wild) rice. Five novel fSNPs were localized in wild rice: four G/A fSNPs in exons 2, 9, and 12 and one T/C fSNP in exon 13. We also identified the three previously reported fSNPs, namely, a G/A fSNP (exon 4), an A/C fSNP (exon 6), and a C/T fSNP (exon 10), which were observed only in cultivated rice, whereas an A/G fSNP (exon 4) was observed exclusively in wild rice. All-against-all comparison of four varietal types or six ecotypes of cultivated rice with wild rice showed that the GBSSI diversity was higher only in wild rice (π = 0.0056). The diversity reduction in cultivated rice can be useful to encompass the origin of this gene GBSSI during its evolution. Significant deviations of positive (wild and indica under balancing selection) and negative (temperate and tropical japonica under purifying selection) Tajima's D values from a neutral model can be informative about the selective sweeps of GBSSI genome insights. Despite the estimation of the differences in population structure and principal component analysis (PCA) between wild and subdivided cultivated subgroups, an inbreeding effect was quantified by FST statistic, signifying the genetic relatedness of GBSSI. Our findings of a novel wild fSNPS can be applicable for future breeding of waxy rice varieties. Furthermore, the signatures of selective sweep can also be of informative into further deeper insights during domestication.

Foods ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 2359
Author(s):  
Thant Zin Maung ◽  
Sang-Ho Chu ◽  
Yong-Jin Park

Granule-bound starch synthase 2 (GBSSII), a paralogous isoform of GBSSI, carries out amylose biosynthesis in rice. Unlike GBSSI, it mainly functions in transient organs, such as leaves. Despite many reports on the starch gene family, little is known about the genetics and genomics of GBSSII. Haplotype analysis was conducted to unveil genetic variations (SNPs and InDels) of GBSSII (OS07G0412100) and it was also performed to gain evolutionary insight through genetic diversity, population genetic structure, and phylogenetic analyses using the KRICE_CORE set (475 rice accessions). Thirty nonsynonymous SNPs (nsSNPs) were detected across the diverse GBSSII coding regions, representing 38 haplotypes, including 13 cultivated, 21 wild, and 4 mixed (a combination of cultivated and wild) varieties. The cultivated haplotypes (C_1–C_13) contained more nsSNPs across the GBSSII genomic region than the wild varieties. Nucleotide diversity analysis highlighted the higher diversity values of the cultivated varieties (weedy = 0.0102, landrace = 0.0093, and bred = 0.0066) than the wild group (0.0045). The cultivated varieties exhibited no reduction in diversity during domestication. Diversity reduction in the japonica and the wild groups was evidenced by the negative Tajima’s D values under purifying selection, suggesting the domestication signatures of GBSSII; however, balancing selection was indicated by positive Tajima’s D values in indica. Principal component analysis and population genetics analyses estimated the ambiguous evolutionary relationships among the cultivated and wild rice groups, indicating highly diverse structural features of the rice accessions within the GBSSII genomic region. FST analysis differentiated most of the classified populations in a range of greater FST values. Our findings provide evolutionary insights into GBSSII and, consequently, a molecular breeding program can be implemented for select desired traits using these diverse nonsynonymous (functional) alleles.


2004 ◽  
Vol 31 (7) ◽  
pp. 671 ◽  
Author(s):  
Takayuki Umemoto ◽  
Noriaki Aoki ◽  
Hongxuan Lin ◽  
Yasunori Nakamura ◽  
Naoyoshi Inouchi ◽  
...  

The natural variation in starch synthase IIa (SSIIa) of rice (Oryza sativa L.) was characterised using near-isogenic lines (NILs). SSIIa is a candidate for the alk gene regulating the alkali disintegration of rice grains, since both genes are genetically mapped at the same position on chromosome 6 and related to starch properties. In this study, we report that the alkali-susceptible cultivar Nipponbare lacked SSIIa activity in endosperm. However, the activity was detected with NILs having the alk allele of alkali-tolerant Kasalath. SSIIa protein was present even in Nipponbare endosperm, but it was not associated with starch granules at the milky stage of endosperm. Three single-nucleotide polymorphisms (SNPs) predicting amino acid substitutions existed between the cDNA sequences of SSIIa of Nipponbare and Kasalath were genotyped with 65 rice cultivars and four wild relatives of cultivated rice. The results obtained explain the potential importance of two of the amino acid residues for starch association of rice SSIIa. An analysis of the chain-length distribution of β-limit dextrin of amylopectin showed that without SSIIa activity, the relative number of A-chains (the short chains without branches) increased and that of B1-chains (the short chains with branches) decreased. This suggests that, given the SSIIa defect, short A-chains could not reach a sufficient length for branching enzymes to act on them to produce B1-chains.


3 Biotech ◽  
2018 ◽  
Vol 9 (1) ◽  
Author(s):  
Firoz Hossain ◽  
Rashmi Chhabra ◽  
Elangbam L. Devi ◽  
Rajkumar U. Zunjare ◽  
Sunil K. Jaiswal ◽  
...  

2012 ◽  
Vol 41 (Special Issue) ◽  
pp. 154-158
Author(s):  
J. Ovesná ◽  
M.-C. Nguyen ◽  
L. Kučera ◽  
V. Holubec

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2020 ◽  
Author(s):  
Yongbo Liu ◽  
Weiqing Wang ◽  
Yonghua Li ◽  
Fang Liu ◽  
Weijuan Han ◽  
...  

Abstract Background: Strategies are still employed to decrease insect damage in crop production, including conventional breeding with wild germplasm resources and transgenic technology with the insertion of foreign genes, while the insect-resistant mechanism of these strategies remains unclear. Results: Under the feeding of brown planthopper (Nilaparvata lugens), cultivated rice (WT) showed less DEGs (568) and DAPs (4) than transgenic rice (2098 and 11) and wild rice CL (1990 and 39) and DX (1932 and 25). Hierarchical cluster of DEGs showed gene expression of CL and DX were similar, slightly distinct to GT, and clearly different from WT. DEGs assigned to the GO terms were less in WT rice than GT, CL and DX, and “Metabolic process”, “cellular process”, “response to stimulus” were dominant. Wild rice CL significantly enriched in KEGG pathways of “Metabolic pathways”, “biosynthesis of secondary metabolites”, “plant-pathogen interaction” and “plant hormone signal transduction”. The iTRAQ analysis confirmed the results of RNA-seq, which showing the least GO terms and KEGG pathways responding to herbivory in the cultivated rice. Synthesize conclusions: This study demonstrated that similarity in the transcriptomic and proteomic response to herbivory for the wild rice and Bt-transgenic rice, while cultivated rice lack of enough pathways in response to herbivory. Our results highlighted the importance of conservation of crop wild species.


BMC Genomics ◽  
2022 ◽  
Vol 23 (1) ◽  
Author(s):  
Chenna Swetha ◽  
Anushree Narjala ◽  
Awadhesh Pandit ◽  
Varsha Tirumalai ◽  
P. V. Shivaprasad

Abstract Background Small non-coding (s)RNAs are involved in the negative regulation of gene expression, playing critical roles in genome integrity, development and metabolic pathways. Targeting of RNAs by ribonucleoprotein complexes of sRNAs bound to Argonaute (AGO) proteins results in cleaved RNAs having precise and predictable 5` ends. While tools to study sliced bits of RNAs to confirm the efficiency of sRNA-mediated regulation are available, they are sub-optimal. In this study, we provide an improvised version of a tool with better efficiency to accurately validate sRNA targets. Results Here, we improvised the CleaveLand tool to identify additional micro (mi)RNA targets that belong to the same family and also other targets within a specified free energy cut-off. These additional targets were otherwise excluded during the default run. We employed these tools to understand the sRNA targeting efficiency in wild and cultivated rice, sequenced degradome from two rice lines, O. nivara and O. sativa indica Pusa Basmati-1 and analyzed variations in sRNA targeting. Our results indicate the existence of multiple miRNA-mediated targeting differences between domesticated and wild species. For example, Os5NG4 was targeted only in wild rice that might be responsible for the poor secondary wall formation when compared to cultivated rice. We also identified differential mRNA targets of secondary sRNAs that were generated after miRNA-mediated cleavage of primary targets. Conclusions We identified many differentially targeted mRNAs between wild and domesticated rice lines. In addition to providing a step-wise guide to generate and analyze degradome datasets, we showed how domestication altered sRNA-mediated cascade silencing during the evolution of indica rice.


ISRN Genetics ◽  
2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
K. Medhabati ◽  
K. Rajiv Das ◽  
M. Rohinikumar ◽  
H. Sunitibala ◽  
Th. Dikash Singh

Genetic divergence of 32 indigenous rice germplasms and five wild rice of which three from Manipur and two wild rice procured from IRRI, Philippines was investigated using Mahalanobis, D2 statistic. Based on twelve agromorphological characters, the thirty-seven germplasms both wild and cultivated were grouped into five clusters based on the relative magnitudes of D2 values following Tocher's method of cluster formation. Based on the rank totals, the characters which contributed maximum towards genetic divergence in the present studies were grain yield/plant, spikelet/panicle, 100 grain weight, grain length, days to 50% flowering, ear bearing tillers/plant, and flag leaf length. In the present study, maximum intercluster distance was estimated between cluster III and (D2=14.09) which was closed followed by clusters II and V (D2=12.50). On the basis of their greater intercluster distance, high value of cluster mean according to the character to be improved and performance of the individual germplasms for the character, the germplasms could be used in hybridization programme for improvement of different plant characters in the rice germplasms of Manipur.


2021 ◽  
Author(s):  
Yong-Chao Xu ◽  
Jie Zhang ◽  
Dong-Yan Zhang ◽  
Ying-Hui Nan ◽  
Song Ge ◽  
...  

Abstract Background Wild rice, including Oryza nivara and Oryza rufipogon, which are considered as the ancestors of Asian cultivated rice (Oryza sativa L.), possess high genetic diversity and serve as a crucial resource for breeding novel cultivars of cultivated rice. Although many rice domestication related traits, such as seed shattering and plant architecture, have been intensively studied at the phenotypic and genomic levels, further investigation is needed to understand the molecular basis of phenotypic differences between cultivated and wild rice. Drought stress is one of the most severe abiotic stresses affecting rice growth and production. Adaptation to drought stress involves a cascade of genes and regulatory factors that form complex networks. Long noncoding natural antisense transcripts (lncNATs), a class of long noncoding RNAs (lncRNAs), regulate the corresponding sense transcripts and play an important role in plant growth and development. However, the contribution of lncNATs to drought stress response in wild rice remains largely unknown. Results Here, we conducted strand-specific RNA sequencing (ssRNA-seq) analysis of Nipponbare (O. sativa ssp. japonica) and two O. nivara accessions (BJ89 and BJ278) to determine the role of lncNATs in drought stress response in wild rice. A total of 1,246 lncRNAs were identified, including 1,091 coding–noncoding NAT pairs, of which 50 were expressed only in Nipponbare, and 77 were expressed only in BJ89 and/or BJ278. Of the 1,091 coding–noncoding NAT pairs, 240 were differentially expressed between control and drought stress conditions. Among these 240 NAT pairs, 12 were detected only in Nipponbare, and 187 were detected uniquely in O. nivara. Furthermore, 10 of the 240 coding–noncoding NAT pairs were correlated with genes previously demonstrated to be involved in stress response; among these, nine pairs were uniquely found in O. nivara, and one pair was shared between O. nivara and Nipponbare. Conclusion We identified lncNATs associated with drought stress response in cultivated rice and O. nivara. These results will improve our understanding of the function of lncNATs in drought tolerance and accelerate rice breeding.


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