Forty-three gene sequences encoding purothionin were characterized from the three species or subspecies of einkorn wheats. These sequences contained 887 bp, among which 92 SNPs including 29 indel loci were detected, g...Forty-three gene sequences encoding purothionin were characterized from the three species or subspecies of einkorn wheats. These sequences contained 887 bp, among which 92 SNPs including 29 indel loci were detected, giving an average SNP frequency of one SNP per 9.64 bases. According to these sequences, 5 SNP markers were successfully designed, which were used to mine the variations ofpurothionin genes of 102 einkorn wheat accessions. Based on the 5 detected SNP loci, 102 einkorn wheat accessions could be divided into 21 haplotypes, among which 11 haplotypes contained a single sample. Phylogenetic analysis indicated that the purothionin genes from einkorn wheats were more closely related to those from D genome than B genome. Seven out of the 43 gene sequences were assumed to be pseudogenes by the definition of containing in-frame stop codons and small insertions/deletions leading to frameshift. In the remaining 36 amino acid sequences, the 8 Cys and Tyr-13 loci in the mature thionin domain which played important roles in the biological activities were all conserved, whereas there were some varieties occurred in some other important amino acid residues such as Lys and Arg.展开更多
In wheat plants at the vegetative growth stage, the shoot apical meristem (SAM) produces leaf primordia. When reproductive growth is initiated, the SAM forms an inflorescence meristem (IM) that differentiates a series...In wheat plants at the vegetative growth stage, the shoot apical meristem (SAM) produces leaf primordia. When reproductive growth is initiated, the SAM forms an inflorescence meristem (IM) that differentiates a series of spikelet meristem (SM) as the branch. The SM then produces a series of floret meristem (FM) as the branch. To identify the mechanisms that regulate formation of the reproductive meristems in wheat, we have investigated a leaf initiation mutant, fushi-darake (fdk) which was developed by ion beam mutagenesis. The morphological traits were compared in wild type (WT) and fdk mutant plants grown in the experimental field. WT plants initiated leaves from SAM at regular intervals in spiral phyllotaxy, while fdk plants had 1/2 alternate phyllotaxy with rapid leaf emergence. The fdk plants have increased numbers of nodes and leaves compared with WT plants. The time interval between successive leaf initiation events (plastochron) was measured in plants grown in a growth chamber. The fdk plants clearly show the rapid leaf emergence, indicating a shortened plastochron. Each tiller in fdk plants branches at the upper part of the culm. The fine structure of organ formation in meristems of fdk plants was examined by scanning electron microscopy (SEM). The SEM analysis indicated that fdk plants show transformation of spikelet meristems into vegetative shoot meristems. In conclusion, the fdk mutant has a heterochronic nature, i.e., both reproductive and vegetative programs were simultaneously in operation during the reproductive phase, resulting in a shortened plastochron and transformation of reproductive spikelets into vegetative shoots.展开更多
基金supported by the National Key Tech-nologies R&D Program of China (2006BAD01A02-23and 2006 BAD13B02-06)the National High Tech-nology Research and Development Program of China(863 Program, 2006AA10Z179 and 2006AA10Z1F8)
文摘Forty-three gene sequences encoding purothionin were characterized from the three species or subspecies of einkorn wheats. These sequences contained 887 bp, among which 92 SNPs including 29 indel loci were detected, giving an average SNP frequency of one SNP per 9.64 bases. According to these sequences, 5 SNP markers were successfully designed, which were used to mine the variations ofpurothionin genes of 102 einkorn wheat accessions. Based on the 5 detected SNP loci, 102 einkorn wheat accessions could be divided into 21 haplotypes, among which 11 haplotypes contained a single sample. Phylogenetic analysis indicated that the purothionin genes from einkorn wheats were more closely related to those from D genome than B genome. Seven out of the 43 gene sequences were assumed to be pseudogenes by the definition of containing in-frame stop codons and small insertions/deletions leading to frameshift. In the remaining 36 amino acid sequences, the 8 Cys and Tyr-13 loci in the mature thionin domain which played important roles in the biological activities were all conserved, whereas there were some varieties occurred in some other important amino acid residues such as Lys and Arg.
文摘In wheat plants at the vegetative growth stage, the shoot apical meristem (SAM) produces leaf primordia. When reproductive growth is initiated, the SAM forms an inflorescence meristem (IM) that differentiates a series of spikelet meristem (SM) as the branch. The SM then produces a series of floret meristem (FM) as the branch. To identify the mechanisms that regulate formation of the reproductive meristems in wheat, we have investigated a leaf initiation mutant, fushi-darake (fdk) which was developed by ion beam mutagenesis. The morphological traits were compared in wild type (WT) and fdk mutant plants grown in the experimental field. WT plants initiated leaves from SAM at regular intervals in spiral phyllotaxy, while fdk plants had 1/2 alternate phyllotaxy with rapid leaf emergence. The fdk plants have increased numbers of nodes and leaves compared with WT plants. The time interval between successive leaf initiation events (plastochron) was measured in plants grown in a growth chamber. The fdk plants clearly show the rapid leaf emergence, indicating a shortened plastochron. Each tiller in fdk plants branches at the upper part of the culm. The fine structure of organ formation in meristems of fdk plants was examined by scanning electron microscopy (SEM). The SEM analysis indicated that fdk plants show transformation of spikelet meristems into vegetative shoot meristems. In conclusion, the fdk mutant has a heterochronic nature, i.e., both reproductive and vegetative programs were simultaneously in operation during the reproductive phase, resulting in a shortened plastochron and transformation of reproductive spikelets into vegetative shoots.
