This study investigates the effects of moisture content control on the characteristics, properties, and in vitro starch digestion of roasted rice powder made from natural high-resistant starch (RS) ...rice varieties. The results demonstrate that adjusting the moisture content before roasting significantly affects the RS content of the roasted rice powder. Among various moisture levels tested, the addition of 15% water (rice-to-water ratio of 85:15) before roasting resulted in the highest RS content, reaching 22.61%. Several key parameters of the rice samples before and after optimal moisture control were analyzed, including thermal stability, chain length distribution, volatile flavor composition, and scanning electron microscopy. Additionally, in vitro digestion properties were measured. The findings revealed that the volatile flavor compounds in the high-RS roasted rice significantly increased compared to non-roasted rice. Moreover, the thermal stability of the rice samples improved, and the chain length distribution exhibited significant changes. The water absorption and expansion properties were significantly lower in the high-RS roasted rice. Furthermore, the in vitro starch digestion of the roasted flour made from high-RS rice showed a significantly lower digestion rate compared to common rice, indicating a lower starch hydrolysis index in high-RS rice with the sbe-rs genotype. Overall, the roasting process of natural high-RS rice modifies its characteristics, increases the RS content, enhances the flavor, and results in a lower starch digestion rate compared to common rice. This study provides valuable data for the food industry to promote the application of high-RS rice varieties with mutations in the SBEIIb gene, such as Youtangdao2 (YTD2).
Foods high in resistant starch (RS) are beneficial to prevent various diseases including diabetes, colon cancers, diarrhea and chronic renal or hepatic diseases. Elevated RS in rice is important for ...public health since rice is a staple food for half of the world population. A japonica mutant 'Jiangtangdao 1' (RS = 11.67%) was crossed with an indica cultivar 'Miyang 23' (RS = 0.41%). The mutant sbe3-rs that explained 60.4% of RS variation was mapped between RM6611 and RM13366 on chromosome 2 (LOD = 36) using 178 F(2) plants genotyped with 106 genome-wide polymorphic SSR markers. Using 656 plants from four F(3:4) families, sbe3-rs was fine mapped to a 573.3 Kb region between InDel 2 and InDel 6 using one STS, five SSRs and seven InDel markers. SBE3 which codes for starch branching enzyme was identified as a candidate gene within the putative region. Nine pairs of primers covering 22 exons were designed to sequence genomic DNA of the wild type for SBE3 and the mutant for sbe3-rs comparatively. Sequence analysis identified a missense mutation site where Leu-599 of the wild was changed to Pro-599 of the mutant in the SBE3 coding region. Because the point mutation resulted in the loss of a restriction enzyme site, sbe3-rs was not digested by a CAPS marker for SpeI site while SBE3 was. Co-segregation of the digestion pattern with RS content among 178 F(2) plants further supported sbe3-rs responsible for RS in rice. As a result, the CAPS marker could be used in marker-assisted breeding to develop rice cultivars with elevated RS which is otherwise difficult to accurately assess in crops. Transgenic technology should be employed for a definitive conclusion of the sbe3-rs.
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Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Foods rich in resistant starch can help prevent various diseases, including diabetes, colon cancers, diarrhea, and chronic renal and hepatic diseases. Variations in starch biosynthesis enzymes could ...contribute to the high content of resistant starch in some cultivars of rice (Oryza sativa L.). Our previously published work indicated that the sbe3-rs gene in the rice mutant line, ‘Jiangtangdao1’ was a putative allele of the rice starch branching enzyme gene SBEIIb (previously known as SBE3); sbe3-rs might control the biosynthesis of the high resistant starch content in the rice line. Biomolecular analysis showed that the activity of SBEs was significantly lower in soluble extracts of immature seeds harvested from ‘Jiangtangdao1’ 15 days after flowering than in the extracts of the wild-type rice line ‘Huaqingdao’. We performed gene complementation assays by introducing the wild-type OsSBEIIb into the sbe3-rs mutant ‘Jiangtangdao1’. The genetically complemented lines demonstrated restored seed-related traits. The structures of endosperm amylopectin and the morphological and physicochemical properties of the starch granules in the transformants recovered to wild-type levels. This study provides evidence that sbe3-rs is a novel allele of OsSBEIIb, responsible for biosynthesis of high resistant starch in ‘Jiangtangdao1’.
Rice production relies on large amounts of synthetic nitrogen fertilizer to meet crop nutritional demands. However, the current fertilizer use efficiency is poor, with an average of 30–50% of total ...applied nitrogen (N) recovered in grains. Consequently, optimizing N availability and N use efficiency (NUE) has become a major target for rice yield improvement, and looking for quantitative trait loci (QTL) associated with NUE can provide useful information for developing nitrogen efficient rice genotypes. The present study aims to identify QTLs associated with NUE and its two components, agronomic NUE (agNUE) and grain nitrogen increase rate (GIR). A recombinant inbred line population (RIL) derived from a cross between Nipponbare and OM052, consisting of 159 F3 individuals was developed and cultivated in low-N (8 kg N/0.67 ha, N8) and high-N (18 kg N/0.67 ha, N18) conditions. Specific length amplified fragment sequencing (SLAF) was used to genotype the RILs and construct a high-density linkage map spanning 1587.70 cM, consisting 2707 SLAF markers with an average interval of 0.59 cM between adjacent marker loci. QTL analysis confirmed four significant QTLs distributed among chromosome 1, 6, and 11, with the proportion of phenotypic variance explained by each QTL ranging from 2.96 to 11.11% and LOD scores from 1.67 to 3.75. Functional annotation of genes located within the QTL intervals revealed NUE putative candidate genes. Overall, the QTLs identified in this study contribute information that could be useful for NUE improvement in rice.
Resistant starch (RS) is beneficial for human health, and especially for diabetics. Considering the high cost and low productivity of the Jiangtangdao 1 rice variety with high RS content, breeding ...high RS rice varieties exhibiting high productivity is essential. A molecular marker-assisted selection strategy was applied to increase RS content in a three-line hybrid rice variety. The functional rice variety Jiangtangdao 1, which contains sbe3-rs (on chr2) that controls the RS content, was used as the high RS content donor parent. Subsequently, male sterile maintainer and restorer lines containing homozygous sbe3-rs were bred using molecular marker-assisted selection combined with traditional breeding methods. The male sterile line was crossed with the restorer lines to identify the optimal hybrid combination with a high RS content. We obtained four combinations for which the yields were >50% higher than those of the control Jiangtangdao 1. In addition, there was no significant difference in the RS content between the combinations and Jiangtangdao 1. The hybrid rice plants with high RS content exhibited favorable agronomic traits and therefore have broad prospects for commercial application.
In this study, Xiushui 134Bt, a highly insect-resistant rice transgenic material with stable expression of CryIAc1 gene in rice plants and no significant changes in main agronomic traits, was ...obtained by means of Agrobacterium-mediated transformation method using japonica rice Xiushui 134 as receptor material. Biosecurity of the transgenic rice Xiushui 134Bt was assessed by rat feeding experiments. Wistar rats were fed a nutritionally balanced diet supplemented with 35% Genetically Modified (LGM) or 70% Genetically Modified (HGM) Xiushui 134Bt, respectively, for 90 days. Compared with the wild-type group (Xiushui 134), there were no significant differences in body weight, total food intake, food conversion rate, relative organ weight, blood routine, blood physiological or biochemical parameters, or histopathological examination between LGM and HGM Bt groups (p > 0.05). These results indicate that the transgenic rice Xiushui 134Bt is non-toxic in laboratory animals and provide guidance for the future commercial release of the transgenic rice Xiushui 134Bt in China.
SUMMARY Understanding and optimizing the process of grain filling helps the quest to maximize rice ( Oryza sativa L.) seed yield and quality, yet the intricate mechanisms at play remain fragmented. ...Transcription factors (TFs) are major players in the gene networks underlying the grain filling process. Here, we employed grain incomplete filling ( OsGIF1 )/ cell wall invertase 2 , a key gene involved in grain filling, to explore its upstream TFs and identified a bZIP family TF, OsbZIP10, to be a transcriptional activator of OsGIF1 . Rice grains of the knockouts of OsbZIP10 showed increased white‐core rates but lower amylose content (AC), leading to better eating and cooking qualities in all genetic backgrounds investigated, though the impact of mutations in OsbZIP10 on grain weight depended on genetic background. Multi‐omics analyses suggested that, in addition to OsGIF1 , multiple genes involved in different biological processes contributing to grain filling were targeted by OsbZIP10 , including OsAGPS1 , a gene encoding the ADP‐Glc pyrophosphorylase (AGPase) small subunit, and genes contributing to homeostasis of reactive oxygen species. Distinct genetic make‐up was observed in OsbZIP10 between japonica and indica rice varieties, with the majority varieties of each subspecies belonging to two different haplotypes that were closely associated with AC. Overexpressing the haplotype linked to high‐AC in the low‐AC genetic background increased AC. Overall, this study sheds crucial light on the significance of the OsbZIP10–OsGIF1 module in the determination of rice grain quality, offering a potential avenue for genetic engineering of rice to produce seeds with tailored attributes.
Weedy rice is a type of rice that produces lower yields and poorer quality grains than cultivated rice. It plagues commercial rice fields in many countries. One strategy to control its proliferation ...is to develop rice varieties that are tolerant to specific herbicides. Acetohydroxy acid synthase (AHAS) mutations have been found to confer herbicide tolerance to rice. Here, we identified a single mutation (S627N) in AHAS from an indica rice variety that conferred tolerance against imidazolinone herbicides, including imazethapyr and imazamox. A japonica rice variety (JD164) was developed to obtain herbicide tolerance by introducing the mutated indica ahas gene. Imidazolinone application was sufficient to efficiently control weedy rice in the JD164 field. Although the imazethapyr treatment caused dwarfing in the JD164 plants, it did not significantly reduce yields. To determine whether the decrease of the ahas mRNA expression caused the dwarfism of JD164 after imazethapyr application, we detected the ahas mRNA level in plants. The abundance of the ahas mRNA in JD164 increased after imidazolinone application, thus excluding the mRNA expression level as a possible cause of dwarfism. Activity assays showed that the mutated AHAS was tolerant to imidazolinone but the catalytic efficiency of the mutated AHAS decreased in its presence. Moreover, the activity of the mutated AHAS decreased more in the presence of imazethapyr than in the presence of imazamox. We observed no difference in the AHAS secondary structures, but homology modeling suggested that the S627N mutation enabled the substrate to access the active site channel in AHAS, resulting in imidazolinone tolerance. Our work combined herbicides with a rice variety to control weedy rice and showed the mechanism of herbicide tolerance in this rice variety.
Resistant starch (RS) is beneficial for human health, and especially for diabetics. Considering the high cost and low productivity of the Jiangtangdao 1 rice variety with high RS content, breeding ...high RS rice varieties exhibiting high productivity is essential. A molecular marker-assisted selection strategy was applied to increase RS content in a three-line hybrid rice variety. The functional rice variety Jiangtangdao 1, which contains sbe3-rs (on chr2) that controls the RS content, was used as the high RS content donor parent. Subsequently, male sterile maintainer and restorer lines containing homozygous sbe3-rs were bred using molecular marker-assisted selection combined with traditional breeding methods. The male sterile line was crossed with the restorer lines to identify the optimal hybrid combination with a high RS content. We obtained four combinations for which the yields were >50% higher than those of the control Jiangtangdao 1. In addition, there was no significant difference in the RS content between the combinations and Jiangtangdao 1. The hybrid rice plants with high RS content exhibited favorable agronomic traits and therefore have broad prospects for commercial application.
Lithium metal batteries (LMBs) using solid-state electrolytes (SSEs) can achieve dual enhancement of energy density and safety performance and have attracted considerable attention. In spite of their ...excellent flexibility and processability, poly(vinylidene fluoride) (PVDF)-based electrolytes, regarded as a prominent member of SSEs in LMBs, suffer from low ionic conductivity and high internal resistance. The structure of PVDF-based composite polymer electrolytes (CPEs) allows them to combine the advantages of inorganic components and PVDF substrates. The use of modification and advanced technology can achieve higher mechanical strength and improved electrochemical properties of PVDF-based CPEs, but their practical application still needs to be explored. This paper reviews recent research progress of PVDF-based CPEs in LMBs, focuses on the methods to improve the electrochemical and safety performance of PVDF-based CPEs, and specifically discusses five aspects of properties upgrading as the main line, namely, the ionic conductivity, ion migration properties, mechanical properties, thermal stability, and electrochemical stability windows. Finally, the challenges and application prospects of high-performance PVDF-based CPEs in future development are presented.
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