Stress induced by low temperature, which represents a widespread environmental factor,strongly affects maize growth and yield. However, the physiological characteristics and molecular regulatory mechanisms of maize se...Stress induced by low temperature, which represents a widespread environmental factor,strongly affects maize growth and yield. However, the physiological characteristics and molecular regulatory mechanisms of maize seedlings in response to cold remain poorly understood. In this study, using RNA-seq, we investigated the transcriptome profiles of two sweet com inbred lines, "Richao"(RC) and C5, under cold stress. A total of 357 and 455 differentially expressed genes(DEGs) were identified in the RC and C5 lines, respectively, 94 DEGs were detected as common DEGs related to cold response in both genotypes, and a total of 589 DEGs were detected as cold tolerance-associated genes. By combining protein function clustering analysis and significantly enriched Gene Ontology(GO) terms analysis,we suggest that transcription factors may play a dominating role in the cold stress response and tolerance of sweet com. Furthermore, 74 differentially expressed transcription factors were identified, of those many genes involved in the metabolism and regulation of hormones. These results expand our understanding of the complex mechanisms involved in chilling tolerance in maize, and provide a set of candidate genes for further genetic analyses.展开更多
Vitamin E,consisting of tocopherols and tocotrienols,serves as a lipid-soluble antioxidant in sweet corn kernels,providing nutrients to both plants and humans.Though the key genes involved in the vitamin E biosynthesi...Vitamin E,consisting of tocopherols and tocotrienols,serves as a lipid-soluble antioxidant in sweet corn kernels,providing nutrients to both plants and humans.Though the key genes involved in the vitamin E biosynthesis pathway have been identified in plants,the genetic architecture of vitamin E content in sweet corn kernels remains largely unclear.In the present study,an association panel of 204 inbred lines of sweet corn was constructed.Seven compounds of vitamin E were quantified in sweet corn kernels at 28 days after pollination.A total of 119 loci for vitamin E were identified using a genome-wide association study based on genotyping by sequencing,and a genetic network of vitamin E was constructed.Candidate genes identified were involved mainly in RNA regulation and protein metabolism.The known gene ZmVTE4,encodingγ-tocopherol methyltransferase,was significantly associated with four traits(α-tocopherol,α-tocotrienol,theα/γ-tocopherol ratio,and theα/γ-tocotrienol ratio).The effects of two causative markers on ZmVTE4 were validated by haplotype analysis.Finally,two elite cultivars(Yuetian 9 and Yuetian 22)with a 4.5-fold increase in the sum ofα-andγ-tocopherols were developed by marker-assisted selection,demonstrating the successful biofortification of sweet corn.Three genes(DAHPS,ADT2,and cmu2)involved in chorismate and tyrosine synthesis were significantly associated with theα/γ-tocotrienol ratio.These results shed light on the genetic architecture of vitamin E and may accelerate the nutritional improvement of sweet corn.展开更多
To improve the amylose content(AC)and resistant starch content(RSC)of maize kernel starch,we employed the CRISPR/Cas9 system to create mutants of starch branching enzyme I(SBEI)and starch branching enzyme IIb(SBEIIb)....To improve the amylose content(AC)and resistant starch content(RSC)of maize kernel starch,we employed the CRISPR/Cas9 system to create mutants of starch branching enzyme I(SBEI)and starch branching enzyme IIb(SBEIIb).A frameshift mutation in SBEI(E1,a nucleotide insertion in exon 6)led to plants with higher RSC(1.07%),lower hundred-kernel weight(HKW,24.71±0.14 g),and lower plant height(PH,218.50±9.42 cm)compared to the wild type(WT).Like the WT,E1 kernel starch had irregular,polygonal shapes with sharp edges.A frameshift mutation in SBEIIb(E2,a four-nucleotide deletion in exon 8)led to higher AC(53.48%)and higher RSC(26.93%)than that for the WT.E2 kernel starch was significantly different from the WT regarding granule morphology,chain length distribution pattern,X-ray diffraction pattern,and thermal characteristics;the starch granules were more irregular in shape and comprised typical B-type crystals.Mutating SBEI and SBEIIb(E12)had a synergistic effect on RSC,HKW,PH,starch properties,and starch biosynthesis-associated gene expression.SBEIIa,SS1,SSIIa,SSIIIa,and SSIIIb were upregulated in E12 endosperm compared to WT endosperm.This study lays the foundation for rapidly improving the starch properties of elite maize lines.展开更多
A comparative study was conducted to elucidate differences in the functional properties of arabinoxylans(AXs)derived from different sweet maize fibers(AX2,AX6,and AX39).AX39 had the highest A/X value of 0.68 and the l...A comparative study was conducted to elucidate differences in the functional properties of arabinoxylans(AXs)derived from different sweet maize fibers(AX2,AX6,and AX39).AX39 had the highest A/X value of 0.68 and the largest Mw,while AX6 contained more disubstituted xylose.The difference in Mw led to the changes in viscosity of AXs.When the concentration was 9%,the difference in viscosity of AXs was obvious:AX39>AX6>AX2,and AX39 showed distinct shear thinning property.Moreover,ferulic acid and p-coumaric acid were the dominant phenolic acids in AXs.The content of ferulic acid was proportional to antioxidant activity,and AX2 with the highest content of ferulic acid(96.13μg/g)had the highest antioxidant activity.The contents of short-chain fatty acids(SCFAs)produced during the in vitro fermentation of AXs were influenced by their structural properties.The total SCFAs of AX39 and AX2 were higher than that in AX6 due to their higher A/X and ferulic acid content.These results indicate that AX from different sources has different structural and functional characteristics,appropriate AXs can be selected according to actual needs to enhance the texture or nutritional value of the food.展开更多
基金supported by the Sciences and Technology Project of Guangdong Province (Nos. 20148070706012, 20158020202006)the Foundation of the President of the Guangdong Academy of Agricultural Sciences (No. 201509)the Science and Information Technology Bureau of Guangzhou (No. 2013J2200083)
文摘Stress induced by low temperature, which represents a widespread environmental factor,strongly affects maize growth and yield. However, the physiological characteristics and molecular regulatory mechanisms of maize seedlings in response to cold remain poorly understood. In this study, using RNA-seq, we investigated the transcriptome profiles of two sweet com inbred lines, "Richao"(RC) and C5, under cold stress. A total of 357 and 455 differentially expressed genes(DEGs) were identified in the RC and C5 lines, respectively, 94 DEGs were detected as common DEGs related to cold response in both genotypes, and a total of 589 DEGs were detected as cold tolerance-associated genes. By combining protein function clustering analysis and significantly enriched Gene Ontology(GO) terms analysis,we suggest that transcription factors may play a dominating role in the cold stress response and tolerance of sweet com. Furthermore, 74 differentially expressed transcription factors were identified, of those many genes involved in the metabolism and regulation of hormones. These results expand our understanding of the complex mechanisms involved in chilling tolerance in maize, and provide a set of candidate genes for further genetic analyses.
基金the National Natural Science Foundation of China(31601309)Science and Technology Planning Project of Guangdong Province(2016B020233004,2015A020209063,2017B090907023)+2 种基金Science and Technology Planning Project of Guangzhou(201804020081)Agricultural Development and Rural Work Special Project-Modern Seed Industry Enhancement Project of Guangdong(201788)the Excellent PhD Program of Guangdong Academy of Agricultural Sciences(2017).
文摘Vitamin E,consisting of tocopherols and tocotrienols,serves as a lipid-soluble antioxidant in sweet corn kernels,providing nutrients to both plants and humans.Though the key genes involved in the vitamin E biosynthesis pathway have been identified in plants,the genetic architecture of vitamin E content in sweet corn kernels remains largely unclear.In the present study,an association panel of 204 inbred lines of sweet corn was constructed.Seven compounds of vitamin E were quantified in sweet corn kernels at 28 days after pollination.A total of 119 loci for vitamin E were identified using a genome-wide association study based on genotyping by sequencing,and a genetic network of vitamin E was constructed.Candidate genes identified were involved mainly in RNA regulation and protein metabolism.The known gene ZmVTE4,encodingγ-tocopherol methyltransferase,was significantly associated with four traits(α-tocopherol,α-tocotrienol,theα/γ-tocopherol ratio,and theα/γ-tocotrienol ratio).The effects of two causative markers on ZmVTE4 were validated by haplotype analysis.Finally,two elite cultivars(Yuetian 9 and Yuetian 22)with a 4.5-fold increase in the sum ofα-andγ-tocopherols were developed by marker-assisted selection,demonstrating the successful biofortification of sweet corn.Three genes(DAHPS,ADT2,and cmu2)involved in chorismate and tyrosine synthesis were significantly associated with theα/γ-tocotrienol ratio.These results shed light on the genetic architecture of vitamin E and may accelerate the nutritional improvement of sweet corn.
基金supported by the National Key Research and Development Program of China(2023YFD1202901)the China Agriculture Research System of MOF and MARA(CARS-02-06)the Key Area Research and Development Program of Guangdong Province(2018B020202008).
文摘To improve the amylose content(AC)and resistant starch content(RSC)of maize kernel starch,we employed the CRISPR/Cas9 system to create mutants of starch branching enzyme I(SBEI)and starch branching enzyme IIb(SBEIIb).A frameshift mutation in SBEI(E1,a nucleotide insertion in exon 6)led to plants with higher RSC(1.07%),lower hundred-kernel weight(HKW,24.71±0.14 g),and lower plant height(PH,218.50±9.42 cm)compared to the wild type(WT).Like the WT,E1 kernel starch had irregular,polygonal shapes with sharp edges.A frameshift mutation in SBEIIb(E2,a four-nucleotide deletion in exon 8)led to higher AC(53.48%)and higher RSC(26.93%)than that for the WT.E2 kernel starch was significantly different from the WT regarding granule morphology,chain length distribution pattern,X-ray diffraction pattern,and thermal characteristics;the starch granules were more irregular in shape and comprised typical B-type crystals.Mutating SBEI and SBEIIb(E12)had a synergistic effect on RSC,HKW,PH,starch properties,and starch biosynthesis-associated gene expression.SBEIIa,SS1,SSIIa,SSIIIa,and SSIIIb were upregulated in E12 endosperm compared to WT endosperm.This study lays the foundation for rapidly improving the starch properties of elite maize lines.
基金financially supported by the National Key R&D Program of China(2022YFF1100101)the Key area research and development program of Guangdong Province(2018B020202008)+2 种基金the Key area research and development program of Hainan Province(ZDYF2021XDNY126)Agricultural competitive industry discipline team building project of Guangdong Academy of Agricultural Sciences(202115TD)the project of Guangdong Key Lab for Crop Germplasm Resources Preservation and Utilization(2020B121201008).
文摘A comparative study was conducted to elucidate differences in the functional properties of arabinoxylans(AXs)derived from different sweet maize fibers(AX2,AX6,and AX39).AX39 had the highest A/X value of 0.68 and the largest Mw,while AX6 contained more disubstituted xylose.The difference in Mw led to the changes in viscosity of AXs.When the concentration was 9%,the difference in viscosity of AXs was obvious:AX39>AX6>AX2,and AX39 showed distinct shear thinning property.Moreover,ferulic acid and p-coumaric acid were the dominant phenolic acids in AXs.The content of ferulic acid was proportional to antioxidant activity,and AX2 with the highest content of ferulic acid(96.13μg/g)had the highest antioxidant activity.The contents of short-chain fatty acids(SCFAs)produced during the in vitro fermentation of AXs were influenced by their structural properties.The total SCFAs of AX39 and AX2 were higher than that in AX6 due to their higher A/X and ferulic acid content.These results indicate that AX from different sources has different structural and functional characteristics,appropriate AXs can be selected according to actual needs to enhance the texture or nutritional value of the food.
