Seed size is an important agronomic trait in melons that directly affects seed germination and subsequent seedling growth.However,the genetic mechanism underlying seed size in melon remains unclear.In the present stud...Seed size is an important agronomic trait in melons that directly affects seed germination and subsequent seedling growth.However,the genetic mechanism underlying seed size in melon remains unclear.In the present study,we employed Bulked-Segregant Analysis sequencing(BSA-seq)to identify a candidate region(~1.35 Mb)on chromosome 6 that corresponds to seed size.This interval was confirmed by QTL mapping of three seed size-related traits from an F2 population across three environments.This mapping region represented nine QTLs that shared an overlapping region on chromosome 6,collectively referred to as qSS6.1.New InDel markers were developed in the qSS6.1 region,narrowing it down to a 68.35 kb interval that contains eight annotated genes.Sequence variation analysis of the eight genes identified a SNP with a C to T transition mutation in the promoter region of MELO3C014002,a leucine-rich repeat receptor-like kinase(LRR-RLK)gene.This mutation affected the promoter activity of the MELO3C014002 gene and was successfully used to differentiate the large-seeded accessions(C-allele)from the small-seeded accessions(T-allele).qRT-PCR revealed differential expression of MELO3C014002 between the two parental lines.Its predicted protein has typical LRR-RLK family domains,and phylogenetic analyses reveled its similarity with the homologs in several plant species.Altogether,these findings suggest MELO3C014002 as the most likely candidate gene involved in melon seed size regulation.Our results will be helpful for better understanding the genetic mechanism regulating seed size in melons and for genetically improving this important trait through molecular breeding pathways.展开更多
Although AGAMOUS-LIKE6 (AGL6) MADS-box genes are ancient with wide distributions in gymnosperms and angiosperms, their functions remain poorly understood. Here, we show the biological role of the AGL6-1ike gene, OsMAD...Although AGAMOUS-LIKE6 (AGL6) MADS-box genes are ancient with wide distributions in gymnosperms and angiosperms, their functions remain poorly understood. Here, we show the biological role of the AGL6-1ike gene, OsMADS6, in specifying floral organ and meristem identities in rice (Oryza sativa L.). OsMADS6 was strongly ex- pressed in the floral meristem at early stages. Subsequently, OsMADS6 transcripts were mainly detectable in paleas, lodicules, carpels and the integument of ovule, as well as in the receptacle. Compared to wild type plants, osmads6 mutants displayed altered palea identity, extra glume-like or mosaic organs, abnormal carpel development and loss of floral meristem determinacy. Strikingly, mutation of a SEPALLATA (SEP)-like gene, OsMADS1 (LHS1), enhanced the defect of osmads6 flowers, and no inner floral organs or glume-like structures were observed in whorls 2 and 3 of osmadsl-z osmads6-1 flowers. Furthermore, the osmadsl-z osmads6-1 double mutants developed severely indetermi- nate floral meristems. Our finding, therefore, suggests that the ancient OsMADS6 gene is able to specify "floral state" by determining floral organ and meristem identities in monocot crop rice together with OsMADS1.展开更多
In red-fleshed kiwifruit,anthocyanin pigmentation is a crucial commercial trait.The MYB-bHLH-WD40(MBW)complex and other transcription factors regulate its accumulation.Herein,a new SEP gene,AcMADS68,was identified as ...In red-fleshed kiwifruit,anthocyanin pigmentation is a crucial commercial trait.The MYB-bHLH-WD40(MBW)complex and other transcription factors regulate its accumulation.Herein,a new SEP gene,AcMADS68,was identified as a regulatory candidate for anthocyanin biosynthesis in the kiwifruit by transcriptome data and bioinformatic analyses.AcMADS68 alone could not induce the accumulation of anthocyanin both in Actinidia arguta fruit and tobacco leaves.However,in combination with AcMYBF110,AcMYB123,and AcbHLH1,AcMADS68 co-overexpression increased anthocyanin biosynthesis,whereas its silencing reduced anthocyanin accumulation.The results of the dual-luciferase reporter,firefly luciferase complementation,yeast two-hybrid and co-immunoprecipitation assays showed that AcMADS68 could interact with both AcMYBF110 and AcMYB123 but not with AcbHLH1,thereby co-regulating anthocyanin biosynthesis by promoting the activation of the target genes,including AcANS,AcF3GT1,and AcGST1.Moreover,AcMADS68 also could activate the promoter of AcbHLH1 surported by dual-luciferase reporter and yeast one-hybrid assays,thereby further amplifying the regulation signals from the MBW complex,thus resulting in enhanced anthocyanin accumulation in the kiwifruit.These findings may facilitate better elucidation of various regulatory mechanisms underlying anthocyanin accumulation and contribute to the quality enhancement of red-fleshed kiwifruit.展开更多
基金the Henan Special Funds for Major Science and Technology,China(221100110400)the Henan Scienti?c and Technological Joint Project for Agricultural Improved Varieties,China(2022010503)the National Natural Science Foundation of China(31902038 and 32072564)。
文摘Seed size is an important agronomic trait in melons that directly affects seed germination and subsequent seedling growth.However,the genetic mechanism underlying seed size in melon remains unclear.In the present study,we employed Bulked-Segregant Analysis sequencing(BSA-seq)to identify a candidate region(~1.35 Mb)on chromosome 6 that corresponds to seed size.This interval was confirmed by QTL mapping of three seed size-related traits from an F2 population across three environments.This mapping region represented nine QTLs that shared an overlapping region on chromosome 6,collectively referred to as qSS6.1.New InDel markers were developed in the qSS6.1 region,narrowing it down to a 68.35 kb interval that contains eight annotated genes.Sequence variation analysis of the eight genes identified a SNP with a C to T transition mutation in the promoter region of MELO3C014002,a leucine-rich repeat receptor-like kinase(LRR-RLK)gene.This mutation affected the promoter activity of the MELO3C014002 gene and was successfully used to differentiate the large-seeded accessions(C-allele)from the small-seeded accessions(T-allele).qRT-PCR revealed differential expression of MELO3C014002 between the two parental lines.Its predicted protein has typical LRR-RLK family domains,and phylogenetic analyses reveled its similarity with the homologs in several plant species.Altogether,these findings suggest MELO3C014002 as the most likely candidate gene involved in melon seed size regulation.Our results will be helpful for better understanding the genetic mechanism regulating seed size in melons and for genetically improving this important trait through molecular breeding pathways.
基金We gratefully acknowledge B Han from National Center for Gene Research, Chinese Academy of Sciences (CAS) and Rice Genome Resource Center (RGRC) for providing BAC clone, cDNA clone and Tosl7 insertion line. We thank Z-J Luo and M-J Chen from Shanghai Jiao Tong University for mutant screening and generation of F2 populations, X-Y Gao from Institute of Plant Physiology and Ecology, SIBS, CAS, for SEM, H Yu from Nation- al University Of Singapore for critical reading of this manuscript and H Ma from Fudan University for helpful discussion. This work was supported by funds from the National Basic Research Program of China (2009CB941500, 2006CB 101700), the National Natural Science Foundation of China (30725022, 30830014 and 90717109) and the Shanghai Leading Academic Discipline Project (B205).
文摘Although AGAMOUS-LIKE6 (AGL6) MADS-box genes are ancient with wide distributions in gymnosperms and angiosperms, their functions remain poorly understood. Here, we show the biological role of the AGL6-1ike gene, OsMADS6, in specifying floral organ and meristem identities in rice (Oryza sativa L.). OsMADS6 was strongly ex- pressed in the floral meristem at early stages. Subsequently, OsMADS6 transcripts were mainly detectable in paleas, lodicules, carpels and the integument of ovule, as well as in the receptacle. Compared to wild type plants, osmads6 mutants displayed altered palea identity, extra glume-like or mosaic organs, abnormal carpel development and loss of floral meristem determinacy. Strikingly, mutation of a SEPALLATA (SEP)-like gene, OsMADS1 (LHS1), enhanced the defect of osmads6 flowers, and no inner floral organs or glume-like structures were observed in whorls 2 and 3 of osmadsl-z osmads6-1 flowers. Furthermore, the osmadsl-z osmads6-1 double mutants developed severely indetermi- nate floral meristems. Our finding, therefore, suggests that the ancient OsMADS6 gene is able to specify "floral state" by determining floral organ and meristem identities in monocot crop rice together with OsMADS1.
基金supported by grants from the National Natural Science Foundation(Grant No.32102312)the modern agricultural industry technology system(Grant No.CARS-26)the National Forestry and Grassland Extension Project(Grant No.K3130219012).
文摘In red-fleshed kiwifruit,anthocyanin pigmentation is a crucial commercial trait.The MYB-bHLH-WD40(MBW)complex and other transcription factors regulate its accumulation.Herein,a new SEP gene,AcMADS68,was identified as a regulatory candidate for anthocyanin biosynthesis in the kiwifruit by transcriptome data and bioinformatic analyses.AcMADS68 alone could not induce the accumulation of anthocyanin both in Actinidia arguta fruit and tobacco leaves.However,in combination with AcMYBF110,AcMYB123,and AcbHLH1,AcMADS68 co-overexpression increased anthocyanin biosynthesis,whereas its silencing reduced anthocyanin accumulation.The results of the dual-luciferase reporter,firefly luciferase complementation,yeast two-hybrid and co-immunoprecipitation assays showed that AcMADS68 could interact with both AcMYBF110 and AcMYB123 but not with AcbHLH1,thereby co-regulating anthocyanin biosynthesis by promoting the activation of the target genes,including AcANS,AcF3GT1,and AcGST1.Moreover,AcMADS68 also could activate the promoter of AcbHLH1 surported by dual-luciferase reporter and yeast one-hybrid assays,thereby further amplifying the regulation signals from the MBW complex,thus resulting in enhanced anthocyanin accumulation in the kiwifruit.These findings may facilitate better elucidation of various regulatory mechanisms underlying anthocyanin accumulation and contribute to the quality enhancement of red-fleshed kiwifruit.
