Plant Gene最新文献

Graminaceous plants take up iron (Fe) from soil using specialized chelating agents known as phytosiderophores, which largely comprise mugineic acids (MAs). Biosynthesis of MAs involves three enzymes, of which nicotianamine aminotransferase (NAAT) catalyses the key step in the synthesis of 2′-deoxymugineic acids (DMA). In the present study, a total of 24 TaNAAT genes distributed on 15 of the 21 bread wheat chromosomes were identified using the whole genome sequence. We also identified NAAT genes in diploid and tetraploid relatives of bread wheat. Two gene duplication events involving NAAT genes were also identified, one in Triticum urartu (AA) and the other in Aegilops tauschii (DD). In the promoter regions, a number of cis-regulatory elements were also identified for responses to biotic and abiotic stresses and to different developmental stages. Phylogenetic analysis using NAAT proteins of wheat and seven other plant species led to the identification of six clusters. Both in silico and qRT-PCR expression analyses indicated relatively higher expression of TaNAAT genes in shoot and root of genotypes with low Fe content. The results provided insights into the structure and function of TaNAAT genes, which may further help in planning strategies to develop high yielding wheat varieties tolerant to Fe-deficiency.

Exploring novel QTLs for drought tolerance traits using a new rice genetic resource would be valuable to dissect the mechanisms underlying the complexity of the trait. Here, we used a recombinant inbred line population to detect the QTL associated with agro-physiological traits under drought stress, in particular incorporating the SNPs and 147 phenotype data, analyzed the transcript expression of genes within QTL using differential gene expression meta-analysis and qRT-PCR technique. Composite interval mapping analysis allowed the detection of 154 QTLs distributed into 66 regions, which included a large QTL cluster called ‘hotspot QTL’ that strongly associated with drought tolerance on rice chromosome 8. We found several genes within the QTL-containing regions that were highly expressed based on the meta-analysis approach. In the future, the QTL reported here may be utilized for marker-assisted breeding and the candidate drought-responsive genes could be characterized for dissecting a comprehensive molecular mechanism of drought tolerance in rice.

Squalene is the crucial intermediate for the biosynthesis of many bioactive triterpenoids, such as phytosterol in plants or cholesterol in animals. Squalene synthase (SQS) is the essential gene of the squalene biosynthetic pathway, which catalyzes the head-to-head condensation of two farnesyl pyrophosphate or farnesyl diphosphate (FPP) molecules in a two-step reaction and formation of linear C₃₀ squalene. SQS ubiquitously occurs in all eukaryotic organisms. However, the activity of this gene varies significantly, leading to diverse squalene content in plants. The present study focused on the variation in the expression landscape of SQS gene copies with varying evolutionary backgrounds. Afterward, a reflection of the sequence divergence on the catalytic structure of the protein was examined. The genome-scale mining of the SQS homologs revealed varying degrees of duplication events, sequence evolution of the gene sequence itself, and the adjoining regulatory architecture. Contrasting expressional patterns and the regulatory modules pinpoint the importance of transcriptional regulation of this essential gene. Three-dimensional organizations of SQS from diverse evolutionary taxa and their consensus structures enlightened the conservation of critical catalytic domains, nonetheless divergence in the majority of the protein. As a whole, the outputs of this study provide some valuable insights for understanding the functional regulation of SQS under different tissues and environments.

Chilli veinal mottle virus (ChiVMV) is a serious potyvirus affecting chilli cultivation in India causing economic yield losses. Breeding resistant varieties/ hybrids is best advocated strategy for viral management. Molecular mapping and markers development greatly facilitates accelerated breeding. Genotyping-by-sequencing was employed for marker discovery and simultaneous genotyping of F2 population developed using contrast parents. Total 6628 single nucleotide polymorphisms (SNP) and 18,125 silicoDArT markers were determined. The SNPs and silicoDArT markers ranged from 280 on chromosome 8 to 625 on chromosome 3 and 857 on chromosome 8 to 1753 on chromosome 3, respectively. Genome wide association study (GWAS) detected 17 SNPs and 21 silicoDArT markers associated with ChiVMV resistance. A major genomic region on chromosome 9 was identified as major candidate loci for ChiVMV resistance. A cluster of defense related genes and elongation translation factors (eIFLE) responsible for disease resistance were predicted within the GWAS regions. A cleaved amplified polymorphic sequence ChiVMVR9_2 CAPS marker was developed for the major resistant locus which was physically mapped at 2,458,715 bp on chromosome 9. This marker can be used in marker-assisted breeding and genomic selection. Further fine mapping of the identified region will facilitate precise marker assisted selection for resistance.

Damage from pre-harvest sprouting leads to lower quality and prices or rejection of wheat grain by reducing Falling Number. In previous studies, the changes in physical and chemical characteristics of wheat grain by pre-harvest sprouting is well studied where few genes controlling it have been identified. To explore their interaction, more genes must be identified. RNAseq analysis was performed on two varieties of soft red winter wheat sharing 82% of 1978 markers with significantly different Falling Numbers. Here, RNAseq analysis revealed 48 genes from eight families with a likely function related to pre-harvest sprouting. Few genes may be a part of the regulatory pathway controlling seed germination while others appear to be downstream germination-related genes. Gene under study, MFT, was previously associated with pre-harvest sprouting in wheat. Whereas FLC, potentially part of the regulatory pathway, was upregulated only in the resistant line (Scotty) at 35 days after anthesis under conditions favoring pre-harvest sprouting. Three other gene families totaling 11 genes had a similar expression pattern.

Plant basic helix-loop-helix (bHLH) transcription factors are involved in diverse biological process. So far, there has been no report to systematically carry out comprehensive identification of bHLH members in Pueraria lobata var. thomsonii (Benth.) (P. thomsonii), a traditional Chinese herb that is an excellent source of puerarin. Phylogenetic analysis showed that 219 bHLH genes were identified in the P. thomsonii and classified into 13 subfamilies. All the PlbHLH genes were distributed on the 11 chromosomes unevenly and the number of PlbHLH genes on each chromosome varied from 12 to 44. Both of tandem and segmental duplications were key factors driving bHLH gene family expansion in P. thomsonii. A total of 20 conserved motifs were found in PlbHLH gene family, 185 PlbHLH members contain more than two introns, and genes within the same subfamily appeared to share similar intron-exon gene structures. The Ka/Ks analysis indicated PlbHLH gene family undergo purifying selection during evolution. Combined the RNA-seq data with the qRT-PCR detection results, PlbHLH79/148/149 were found to be the most probably candidate genes which were involved in puerarin biosynthesis pathway. Together, our study provided a good foundation for further research into the regulatory mechanism of the candidate PlbHLH proteins for puerarin biosynthesis in P. thomsonii.

As the tomato fruit grows, it goes through different developmental stages until it acquires its full size. This size is achieved with the completion οf the Μature Green stage of tomato development, after which the fruit enters the Turning stage, signifying the passage from growth to ripening, where it gradually loses its green color in favor of red and begins to soften. Until it reaches the Mature Green, the tomato goes through a series of cell divisions and expansions. Several vital factors control and affect the final size of the tomato. Those factors include genes controlling the cells' size and structure, the meristematic tissue, growth hormones essential for the initiation of the fruit, the compartmentalization of the fruit, as well as genes respοnsible fοr the structure οf the cell wall. In this review, we present critical genetic and hormonal factors that influence the final size of a fruit. Tomato is a model οrganism for elucidating fleshy fruit growth and development. In this review we emphasize on factors affecting the fruit's final size up tο the completion οf the Mature Green growth phase, where the fruits reach their prime size.