Coumarate 3-hydroxylase(C3h)genes participate in the synthesis of lignin and may affect the properties of wood that are important for its commercial value.A better understanding of the natural variation in C3h genes a...Coumarate 3-hydroxylase(C3h)genes participate in the synthesis of lignin and may affect the properties of wood that are important for its commercial value.A better understanding of the natural variation in C3h genes and their associations to wood properties is required to effectively improve wood quality.We used a candidate gene-based association mapping approach to identify CfC3h allelic variants associated with traits that affect the wood properties of Catalpa fargesii.We first isolated the full-length CfC3h cDNA(1825 bp),which was expressed at relatively high levels in xylem according to real time-polymerase chain reaction.In totally,17 common single-nucleotide polymorphisms(minor allele frequency>5%)were identified through cloning and sequencing the CfC3h locus from a mapping population(including 88 unrelated natural C.fargesii individuals collected from main distribution area).Nucleotide diversity and linkage disequilibrium(LD)in CfC3h indicate that CfC3h has low nucleotide diversity(π_(t)=0.0031 andθ_(w)=0.0103)and relatively low LD(within 1800 bp;r^(2)≥0.1).An association analysis identified eight common single-nucleotide polymorphisms(SNPs)(false discovery rate,Q<0.10)and ten haplotypes(Q<0.10)associated with wood properties,explaining 4.92-12.09%of the phenotypic variance in an association population consisted of 125 unrelated natural individuals(The 88 individuals from the mapping population were comprised in the association population).Our study would provide new insight into C3h gene affecting wood quality,and the SNP markers identified would have potential applications in marker-assisted breeding in the future.展开更多
Catalpa fargesii is an important economic tree species used for furniture and timber production because of its high density and hardness.Its survival and growth are severely aff ected and primarily limited by drought ...Catalpa fargesii is an important economic tree species used for furniture and timber production because of its high density and hardness.Its survival and growth are severely aff ected and primarily limited by drought stress.Thus,to better understand the mechanism of drought resistance in C.fargesii,we used qRT-PCR to reveal signifi cantly diff erent expression of three plasma membrane intrinsic protein genes:CfPIP1-1,CfPIP1-2 and CfPIP1-4.We then cloned their full-length cDNA sequences and characterized the encoded proteins.We analyzed the genes phylogenetically and predicted conserved motifs,domains,and secondary and tertiary structures.To verify the function ofthe CfPIP1 genes further,we ectopically expressed CfPIP1 transgenes in Arabidopsis thaliana.The results showed that CfPIP1-1,CfPIP1-2 and CfPIP1-4 had several characteristics of aquaporins.The transgenic plants grew better than the WT plants did under drought stress,and overexpression of the CfPIP1 genes increased the plant water content and resistance to drought.Thus,CfPIP1-1,CfPIP1-2 and CfPIP1-4 of C.fargesii play key roles in regulating the intracellular and extracellular water balance and in mediating the plant response to drought.展开更多
基金This work was supported by the National Key Research and Development Program of China[No.2017YFD0600201]Forestry Industry Research Special Funds for Public Welfare Projects[No.201404101].
文摘Coumarate 3-hydroxylase(C3h)genes participate in the synthesis of lignin and may affect the properties of wood that are important for its commercial value.A better understanding of the natural variation in C3h genes and their associations to wood properties is required to effectively improve wood quality.We used a candidate gene-based association mapping approach to identify CfC3h allelic variants associated with traits that affect the wood properties of Catalpa fargesii.We first isolated the full-length CfC3h cDNA(1825 bp),which was expressed at relatively high levels in xylem according to real time-polymerase chain reaction.In totally,17 common single-nucleotide polymorphisms(minor allele frequency>5%)were identified through cloning and sequencing the CfC3h locus from a mapping population(including 88 unrelated natural C.fargesii individuals collected from main distribution area).Nucleotide diversity and linkage disequilibrium(LD)in CfC3h indicate that CfC3h has low nucleotide diversity(π_(t)=0.0031 andθ_(w)=0.0103)and relatively low LD(within 1800 bp;r^(2)≥0.1).An association analysis identified eight common single-nucleotide polymorphisms(SNPs)(false discovery rate,Q<0.10)and ten haplotypes(Q<0.10)associated with wood properties,explaining 4.92-12.09%of the phenotypic variance in an association population consisted of 125 unrelated natural individuals(The 88 individuals from the mapping population were comprised in the association population).Our study would provide new insight into C3h gene affecting wood quality,and the SNP markers identified would have potential applications in marker-assisted breeding in the future.
基金Fundamental Research Funds of Chinese Academy of Forestry(CAFYBB2014QA004).
文摘Catalpa fargesii is an important economic tree species used for furniture and timber production because of its high density and hardness.Its survival and growth are severely aff ected and primarily limited by drought stress.Thus,to better understand the mechanism of drought resistance in C.fargesii,we used qRT-PCR to reveal signifi cantly diff erent expression of three plasma membrane intrinsic protein genes:CfPIP1-1,CfPIP1-2 and CfPIP1-4.We then cloned their full-length cDNA sequences and characterized the encoded proteins.We analyzed the genes phylogenetically and predicted conserved motifs,domains,and secondary and tertiary structures.To verify the function ofthe CfPIP1 genes further,we ectopically expressed CfPIP1 transgenes in Arabidopsis thaliana.The results showed that CfPIP1-1,CfPIP1-2 and CfPIP1-4 had several characteristics of aquaporins.The transgenic plants grew better than the WT plants did under drought stress,and overexpression of the CfPIP1 genes increased the plant water content and resistance to drought.Thus,CfPIP1-1,CfPIP1-2 and CfPIP1-4 of C.fargesii play key roles in regulating the intracellular and extracellular water balance and in mediating the plant response to drought.
