A Major Locus on Wheat Chromosome 7B Associated With Late-Maturity α-Amylase Encodes a Putative ent-Copalyl Diphosphate Synthase

Many wheat varieties have the potential to develop unacceptably high levels of α-amylase in the grains if exposed to a cool temperature shock or simply cool temperature during the early to middle stages of grain filling. This phenomenon is referred to as late maturity α-amylase (LMA). The enzyme persists in the grain until harvest and may result in wheat with a low Falling Number that does not meet receival and export specifications. Resistance to LMA is therefore a valuable target for wheat breeders and wheat industries in general. Genetic evidence implicating a locus on the long arm of chromosome 7B in variation in LMA phenotype was confirmed in this investigation. Through intensive fine-mapping an ent-copalyl diphosphate synthase (CPS), hitherto named LMA-1, was identified as the likely candidate gene associated with variation in LMA phenotype. Single Nucleotide Polymorphisms (SNPs) within the LMA-1 coding sequence of Chinese Spring, Maringa and Halberd result in either prematurely terminated or functionally altered proteins that are associated with useful levels of resistance to LMA. LMA-1 transcripts detected in de-embryonated grain tissue from around 15 days after anthesis, several days before the synthesis of α-amylase, were low in the resistant varieties Chinese Spring and Maringa compared with LMA susceptible genotype Spica. This was associated with a dramatic reduction in the concentrations of intermediates in the gibberellin biosynthesis pathway such as GA19, evidence that LMA-1 was functioning as CPS in the gibberellin biosynthesis pathway. A survey of a large collection of Australian and international wheat varieties distinguished 9 major haplotypes at the LMA-1 locus. Generally, within classes, there was notable variation for LMA phenotype and evidence for genotypes whose resistance is presumed to be due to genetic loci located elsewhere on the wheat genome. Further investigation is required to characterize the sequence of steps between LMA-1 and α-amylase synthesis as well as to gain a better understanding of the role and potential impact of other genetic loci. Diagnostic markers for sources of resistance and SNP variation reported in this study should assist breeders to deploy resistance associated with LMA-1 variants in breeding programs.

Genome-wide identification and analysis of WRKY gene family in jute(Corchorus capsularis)

Background WRKY transcription factor is a kind of transcription factor which plays an important role in plant response to biotic, abiotic stress, plant growth and development. However, little information was available about the WRKY genes in jute ( Corchorus capsularis ).Results In the present study, 43 jute WRKY (CcWRKY) genes were identified by using Pfam database domain search and BLAST homology alignment based on the transcriptome data of jute. And the gene structure, phylogeny, conserved domain and three-dimensional structure of protein were also analyzed by GSDS2.0, MEGA7.0, DNAMAN5.0, WebLogo 3 and SWISS-MODEL bioinformatics tools. According to the WRKY conserved domain features and the evolution analysis with Arabidopsis thaliana , 43 members were divided into three classes: I, II and III containing 9, 28, 6 members, respectively. According to the evolutionary relationship, class II further divided into five subclasses: II-a (2), II-b (7), II-c (7), II-d (6) and II-e (6). Genetic structure analysis showed that exon and intron number of CcWRKY genes had high variability (3-11 exons), even within the same subgroup. Most of the CcWRKY genes were expressed in different tissues, but they were mainly expressed in stem bark and stem stick. After GA 3 stress, the expression of most WRKY genes in GA 3 -sensitive variety "Aidianyehuangma" was significantly different from that of normal variety "Huangma 179". These results indicated that CcWRKY genes play an important role in gibberellin biosynthesis pathway and fiber development.Conclusions CcWRKY proteins are highly conserved, the length of the gene sequence and the number of introns varied widely, all WRKY genes showed a variety of expression patterns in different tissues, most of the WRKY genes responded to GA 3 stress, which play an important role in gibberellin biosynthesis pathway and bast fiber development.

Genome-wide identification and analysis of WRKY gene family in jute (Corchorus capsularis)

Background WRKY transcription factor is a kind of transcription factor which plays an important role in plant response to biotic, abiotic stress, plant growth and development. However, little information was available about the WRKY genes in jute ( Corchorus capsularis ).Results In the present study, 43 jute WRKY (CcWRKY) genes were identified by using Pfam database domain search and BLAST homology alignment based on the transcriptome data of jute. And the gene structure, phylogeny, conserved domain and three-dimensional structure of protein were also analyzed by GSDS2.0, MEGA7.0, DNAMAN5.0, WebLogo 3 and SWISS-MODEL bioinformatics tools. According to the WRKY conserved domain features and the evolution analysis with Arabidopsis thaliana , 43 members were divided into three classes: I, II and III containing 9, 28, 6 members, respectively. According to the evolutionary relationship, class II further divided into five subclasses: II-a (2), II-b (7), II-c (7), II-d (6) and II-e (6). Genetic structure analysis showed that exon and intron number of CcWRKY genes had high variability (3-11 exons), even within the same subgroup. Most of the CcWRKY genes were expressed in different tissues, but they were mainly expressed in stem bark and stem stick. After GA 3 stress, the expression of most WRKY genes in GA 3 -sensitive variety "Aidianyehuangma" was significantly different from that of normal variety "Huangma 179". These results indicated that CcWRKY genes play an important role in gibberellin biosynthesis pathway and fiber development.Conclusions CcWRKY proteins are highly conserved, the length of the gene sequence and the number of introns varied widely, all WRKY genes showed a variety of expression patterns in different tissues, most of the WRKY genes responded to GA 3 stress, which play an important role in gibberellin biosynthesis pathway and bast fiber development.