Basic helix-loop-helix(bHLH)transcription factors regulate diverse plant processes,particularly anthocyanin biosynthesis through the MYB-bHLH-WD40 complex.Despite snapdragon(Antirrhinum majus)serving as a classical mo...Basic helix-loop-helix(bHLH)transcription factors regulate diverse plant processes,particularly anthocyanin biosynthesis through the MYB-bHLH-WD40 complex.Despite snapdragon(Antirrhinum majus)serving as a classical model for studying flower pigmentation genetics,its bHLH gene family has rarely been comprehensively characterized.Here,we performed a genome-wide identification and systematic characterization of the bHLH gene family in A.majus,with a focus on candidates involved in anthocyanin biosynthesis.A total of 150 AmbHLH genes were identified and subjected to in-silico analyses,including phylogenetic classification,structural analysis,and promoter cis-element characterization.Comparative transcriptomic profiling between anthocyanin-poor(“SIPPE50”,Green)and anthocyanin-rich(“JI2R”,Red)snapdragon lines highlighted eight differentially expressed AmbHLHs.AmbHLH001,AmbHLH002,and AmbHLH042 showed significant upregulation in the anthocyanin-rich line and showed positive correlations with the expression of key anthocyanin biosynthetic genes.Among these,AmbHLH002 was prioritized as a candidate and was assessed via heterologous overexpression in tomatoes.Notably,AmbHLH002 is a newly identified regulator whose overexpression in tomato resulted in visible purple pigmentation and increased anthocyanin accumulation.These findings support the view that AmbHLH002 acts as a positive regulator,with phylogenetic evidence for conservation of anthocyanin biosynthesis,presenting valuable potential for engineering pigmentation traits in ornamental plants and serving as a candidate visible marker for plant genetic transformation.展开更多
Rice grows in flooded paddy fields and takes up ammonium as the preferred nitrogen （N） source. Ammonium uptake is facilitated by a family of integral membrane proteins known as ammonium transporters found in all dom...Rice grows in flooded paddy fields and takes up ammonium as the preferred nitrogen （N） source. Ammonium uptake is facilitated by a family of integral membrane proteins known as ammonium transporters found in all domains of life. However, the molecular mechanism and functional characteristics of the ammonium transporters （AMT） in rice have not been determined in detail yet. In this review, we report a genome-wide search for AMT genes in rice, resulting in the increase of the number of potential AMT proteins to at least 12, including members of both the alpha and beta sub-groups. Analysis of the predicted protein sequences for the 12 OsAMT proteins identified many conserved phosphorylation sites in both the alpha and beta group members, which could potentially play a role in controlling the activity of the transporters. Present knowledge of the expression of rice AMT genes is also summarized in detail. Future studies should focus on the structural and functional characteristics of OsAMT proteins to provide insight into the mechanism of ammonium uptake and its regulation in rice. Such research could improve utilization and decrease wastage of N fertilizer in rice cultivation.展开更多
Scutellaria baicalensis Georgi produces abundant root-specific f lavones(RSFs),which provide various benefits to human health.We have elucidated the complete biosynthetic pathways of baicalein and wogonin.However,the ...Scutellaria baicalensis Georgi produces abundant root-specific f lavones(RSFs),which provide various benefits to human health.We have elucidated the complete biosynthetic pathways of baicalein and wogonin.However,the transcriptional regulation of f lavone biosynthesis in S.baicalensis remains unclear.We show that the SbMYB3 transcription factor functions as a transcriptional activator involved in the biosynthesis of RSFs in S.baicalensis.Yeast one-hybrid and transcriptional activation assays showed that SbMYB3 binds to the promoter of flavone synthase II-2(SbFNSII-2)and enhances its transcription.In S.baicalensis hairy roots,RNAi of SbMYB3 reduced the accumulation of baicalin and wogonoside,and SbMYB3 knockout decreased the biosynthesis of baicalein,baicalin,wogonin,and wogonoside,whereas SbMYB3 overexpression enhanced the contents of baicalein,baicalin,wogonin,and wogonoside.Transcript profiling by qRT–PCR demonstrated that SbMYB3 activates SbFNSII-2 expression directly,thus leading to more abundant accumulation of RSFs.This study provides a potential target for metabolic engineering of RSFs.展开更多
Carotenoids,such asβ-carotene,accumulate in chromoplasts of various fleshy fruits,awarding them with colors,aromas,and nutrients.The Orange(CmOr)gene controlsβ-carotene accumulation in melon fruit by posttranslation...Carotenoids,such asβ-carotene,accumulate in chromoplasts of various fleshy fruits,awarding them with colors,aromas,and nutrients.The Orange(CmOr)gene controlsβ-carotene accumulation in melon fruit by posttranslationally enhancing carotenogenesis and repressingβ-carotene turnover in chromoplasts.Carotenoid isomerase(CRTISO)isomerizes yellow prolycopene into red lycopene,a prerequisite for further metabolism intoβ-carotene.We comparatively analyzed the developing fruit transcriptomes of orange-colored melon and its two isogenic EMS-induced mutants,low-β(Cmor)and yofi(Cmcrtiso).The Cmor mutation in low-βcaused a major transcriptomic change in the mature fruit.In contrast,the Cmcrtiso mutation in yofi significantly changed the transcriptome only in early fruit developmental stages.These findings indicate that melon fruit transcriptome is primarily altered by changes in carotenoid metabolic flux and plastid conversion,but minimally by carotenoid composition in the ripe fruit.Clustering of the differentially expressed genes into functional groups revealed an association between fruit carotenoid metabolic flux with the maintenance of the photosynthetic apparatus in fruit chloroplasts.Moreover,large numbers of thylakoid localized photosynthetic genes were differentially expressed in low-β.CmOR family proteins were found to physically interact with light-harvesting chlorophyll a–b binding proteins,suggesting a new role of CmOR for chloroplast maintenance in melon fruit.This study brings more insights into the cellular and metabolic processes associated with fruit carotenoid accumulation in melon fruit and reveals a new maintenance mechanism of the photosynthetic apparatus for plastid development.展开更多
Blooming seasonality is an important trait in ornamental plants and was selected by humans.Wild roses flower only in spring whereas most cultivated modern roses can flower continuously.This trait is explained by a mut...Blooming seasonality is an important trait in ornamental plants and was selected by humans.Wild roses flower only in spring whereas most cultivated modern roses can flower continuously.This trait is explained by a mutation of a floral repressor gene,RoKSN,a TFL1 homologue.In this work,we studied the origin,the diversity and the selection of the RoKSN gene.We analyzed 270 accessions,including wild and old cultivated Asian and European roses as well as modern roses.By sequencing the RoKSN gene,we proposed that the allele responsible for continuous-flowering,RoKSN copia,originated from Chinese wild roses(Indicae section),with a recent insertion of the copia element.Old cultivated Asian roses with the RoKSN copia allele were introduced in Europe,and the RoKSN copia allele was progressively selected during the 19th and 20th centuries,leading to continuous-flowering modern roses.Furthermore,we detected a new allele,RoKSN A181,leading to a weak reblooming.This allele encodes a functional floral repressor and is responsible for a moderate accumulation of RoKSN transcripts.A transient selection of this RoKSN A181 allele was observed during the 19th century.Our work highlights the selection of different alleles at the RoKSN locus for recurrent blooming in rose.展开更多
Response to vernalization and photoperiod are the main determinants controlling the time to flowering in temperate cereals. While the individual genes that determine a plant's response to these environmental signa...Response to vernalization and photoperiod are the main determinants controlling the time to flowering in temperate cereals. While the individual genes that determine a plant's response to these environmental signals are well characterized, the combinatorial effect on flowering time of allelic variants for multiple genes remains unresolved. This study investigated the genetic control of flowering-time in a biparental population of spring barley, derived from a wide cross between a late-flowering European and an early-flowering North-American cultivar. While the major flowering time genes are not segregating in the Beka ×Logan cross, large variation in flowering was observed. We identified five QTL, with both parents found to contribute early alleles. The catalog of QTL discovered aligns with several candidate genes affecting flowering time in barley. The combination of particular alleles at HvCEN, HvELF3 and HvFT1 in Logan are responsible for the earliness of this cultivar. Interestingly, earliness for flowering could be further enhanced, with Beka found to contribute three early alleles, including a QTL colocating with a HvFD-like gene, suggesting that there are diverse aspects of the flowering-time pathway that have been manipulated in these two cultivars. Epistatic interactions between flowering-time QTL or candidate genes were observed in field data and confirmed under controlled conditions. The results of this study link photoperiod-dependent flowering-time genes with earliness per se genes into a single model, thus providing a unique framework that can be used by geneticists and breeders to optimize flowering time in barley.展开更多
基金funded by the USDANIFA grant 2019-67013-29236the USDA HATCH program FLA-MFC-006387,awarded to Heqiang Huo.
文摘Basic helix-loop-helix(bHLH)transcription factors regulate diverse plant processes,particularly anthocyanin biosynthesis through the MYB-bHLH-WD40 complex.Despite snapdragon(Antirrhinum majus)serving as a classical model for studying flower pigmentation genetics,its bHLH gene family has rarely been comprehensively characterized.Here,we performed a genome-wide identification and systematic characterization of the bHLH gene family in A.majus,with a focus on candidates involved in anthocyanin biosynthesis.A total of 150 AmbHLH genes were identified and subjected to in-silico analyses,including phylogenetic classification,structural analysis,and promoter cis-element characterization.Comparative transcriptomic profiling between anthocyanin-poor(“SIPPE50”,Green)and anthocyanin-rich(“JI2R”,Red)snapdragon lines highlighted eight differentially expressed AmbHLHs.AmbHLH001,AmbHLH002,and AmbHLH042 showed significant upregulation in the anthocyanin-rich line and showed positive correlations with the expression of key anthocyanin biosynthetic genes.Among these,AmbHLH002 was prioritized as a candidate and was assessed via heterologous overexpression in tomatoes.Notably,AmbHLH002 is a newly identified regulator whose overexpression in tomato resulted in visible purple pigmentation and increased anthocyanin accumulation.These findings support the view that AmbHLH002 acts as a positive regulator,with phylogenetic evidence for conservation of anthocyanin biosynthesis,presenting valuable potential for engineering pigmentation traits in ornamental plants and serving as a candidate visible marker for plant genetic transformation.
基金supported by the China Postdoctoral Science Foundation (Grant No. 20070421031)the National Basic Research Program of China (Grant No. 2007CB109303)Knowledge Innovation Project of the Chinese Academy of Sciences (Grant No. KSCX2-YW-N-002)
文摘Rice grows in flooded paddy fields and takes up ammonium as the preferred nitrogen （N） source. Ammonium uptake is facilitated by a family of integral membrane proteins known as ammonium transporters found in all domains of life. However, the molecular mechanism and functional characteristics of the ammonium transporters （AMT） in rice have not been determined in detail yet. In this review, we report a genome-wide search for AMT genes in rice, resulting in the increase of the number of potential AMT proteins to at least 12, including members of both the alpha and beta sub-groups. Analysis of the predicted protein sequences for the 12 OsAMT proteins identified many conserved phosphorylation sites in both the alpha and beta group members, which could potentially play a role in controlling the activity of the transporters. Present knowledge of the expression of rice AMT genes is also summarized in detail. Future studies should focus on the structural and functional characteristics of OsAMT proteins to provide insight into the mechanism of ammonium uptake and its regulation in rice. Such research could improve utilization and decrease wastage of N fertilizer in rice cultivation.
基金supported by the National Key R&D Program of China(2018YFC1706200)the National Natural Science Foundation of China(31870282 and 31700268)+1 种基金the Chenshan Special Fund for Shanghai Landscaping Administration Bureau Program(G182401,G192419,and G212401)the Youth Innovation Promotion Association,Chinese Academy of Sciences.
文摘Scutellaria baicalensis Georgi produces abundant root-specific f lavones(RSFs),which provide various benefits to human health.We have elucidated the complete biosynthetic pathways of baicalein and wogonin.However,the transcriptional regulation of f lavone biosynthesis in S.baicalensis remains unclear.We show that the SbMYB3 transcription factor functions as a transcriptional activator involved in the biosynthesis of RSFs in S.baicalensis.Yeast one-hybrid and transcriptional activation assays showed that SbMYB3 binds to the promoter of flavone synthase II-2(SbFNSII-2)and enhances its transcription.In S.baicalensis hairy roots,RNAi of SbMYB3 reduced the accumulation of baicalin and wogonoside,and SbMYB3 knockout decreased the biosynthesis of baicalein,baicalin,wogonin,and wogonoside,whereas SbMYB3 overexpression enhanced the contents of baicalein,baicalin,wogonin,and wogonoside.Transcript profiling by qRT–PCR demonstrated that SbMYB3 activates SbFNSII-2 expression directly,thus leading to more abundant accumulation of RSFs.This study provides a potential target for metabolic engineering of RSFs.
基金the United States-Israel Binational Agricultural Research and Development Fund(grant no.US-4918-16CR)the Agriculture and Food Research Initiative competitive award(grant no.2019-67013-29162)from the USDA National Institute of Food and Agriculture,and the USDA-ARS fund.
文摘Carotenoids,such asβ-carotene,accumulate in chromoplasts of various fleshy fruits,awarding them with colors,aromas,and nutrients.The Orange(CmOr)gene controlsβ-carotene accumulation in melon fruit by posttranslationally enhancing carotenogenesis and repressingβ-carotene turnover in chromoplasts.Carotenoid isomerase(CRTISO)isomerizes yellow prolycopene into red lycopene,a prerequisite for further metabolism intoβ-carotene.We comparatively analyzed the developing fruit transcriptomes of orange-colored melon and its two isogenic EMS-induced mutants,low-β(Cmor)and yofi(Cmcrtiso).The Cmor mutation in low-βcaused a major transcriptomic change in the mature fruit.In contrast,the Cmcrtiso mutation in yofi significantly changed the transcriptome only in early fruit developmental stages.These findings indicate that melon fruit transcriptome is primarily altered by changes in carotenoid metabolic flux and plastid conversion,but minimally by carotenoid composition in the ripe fruit.Clustering of the differentially expressed genes into functional groups revealed an association between fruit carotenoid metabolic flux with the maintenance of the photosynthetic apparatus in fruit chloroplasts.Moreover,large numbers of thylakoid localized photosynthetic genes were differentially expressed in low-β.CmOR family proteins were found to physically interact with light-harvesting chlorophyll a–b binding proteins,suggesting a new role of CmOR for chloroplast maintenance in melon fruit.This study brings more insights into the cellular and metabolic processes associated with fruit carotenoid accumulation in melon fruit and reveals a new maintenance mechanism of the photosynthetic apparatus for plastid development.
文摘Blooming seasonality is an important trait in ornamental plants and was selected by humans.Wild roses flower only in spring whereas most cultivated modern roses can flower continuously.This trait is explained by a mutation of a floral repressor gene,RoKSN,a TFL1 homologue.In this work,we studied the origin,the diversity and the selection of the RoKSN gene.We analyzed 270 accessions,including wild and old cultivated Asian and European roses as well as modern roses.By sequencing the RoKSN gene,we proposed that the allele responsible for continuous-flowering,RoKSN copia,originated from Chinese wild roses(Indicae section),with a recent insertion of the copia element.Old cultivated Asian roses with the RoKSN copia allele were introduced in Europe,and the RoKSN copia allele was progressively selected during the 19th and 20th centuries,leading to continuous-flowering modern roses.Furthermore,we detected a new allele,RoKSN A181,leading to a weak reblooming.This allele encodes a functional floral repressor and is responsible for a moderate accumulation of RoKSN transcripts.A transient selection of this RoKSN A181 allele was observed during the 19th century.Our work highlights the selection of different alleles at the RoKSN locus for recurrent blooming in rose.
基金supported by the Spanish Ministry of Economy and Competitiveness(grant numbers AGL2010-21929 and AGL2013-48756-R)the Spanish Ministry of Economy and Competitiveness,the Agencia Estatal de Investigación,and the European Regional Development Fund(grant number AGL2016–80967-R)Government of Aragon(Research Group A08_20R)。
文摘Response to vernalization and photoperiod are the main determinants controlling the time to flowering in temperate cereals. While the individual genes that determine a plant's response to these environmental signals are well characterized, the combinatorial effect on flowering time of allelic variants for multiple genes remains unresolved. This study investigated the genetic control of flowering-time in a biparental population of spring barley, derived from a wide cross between a late-flowering European and an early-flowering North-American cultivar. While the major flowering time genes are not segregating in the Beka ×Logan cross, large variation in flowering was observed. We identified five QTL, with both parents found to contribute early alleles. The catalog of QTL discovered aligns with several candidate genes affecting flowering time in barley. The combination of particular alleles at HvCEN, HvELF3 and HvFT1 in Logan are responsible for the earliness of this cultivar. Interestingly, earliness for flowering could be further enhanced, with Beka found to contribute three early alleles, including a QTL colocating with a HvFD-like gene, suggesting that there are diverse aspects of the flowering-time pathway that have been manipulated in these two cultivars. Epistatic interactions between flowering-time QTL or candidate genes were observed in field data and confirmed under controlled conditions. The results of this study link photoperiod-dependent flowering-time genes with earliness per se genes into a single model, thus providing a unique framework that can be used by geneticists and breeders to optimize flowering time in barley.
