Fang JingGui

Comparison and verification of the genes involved in ethylene biosynthesis and signaling in apple, grape, peach, pear and strawberry

Ethylene, which plays important roles in regulating plants’ life cycles, is biologically active in trace amounts, and its effects are of great commercial importance. The large-scale identification and comparison of the genes, which are involved in ethylene biosynthesis and signaling in multiple plants has not been reported. In this study, some key enzymes that involved in ethylene biosynthesis and signaling pathway in two non-climacteric fruits and three climacteric fruits have been identified through the comparison of gene copy number and related ESTs. The total EST number of the ethylene biosynthesis and signaling pathway related genes in grape and apple was more than that in peach. However, the ratios of the EST number in fruit to those in all the other tissues of the related genes in peach were more than that in apple and grape. We verified 27 genes in pear, 18 genes in apple, 23 genes in strawberry, 16 genes in peach and 23 genes in grape. The result showed that the transcript amounts of different members in the same gene family will be different in the expression and function of fruit ripening process. The difference between non-climacteric fruits and climacteric fruits was that the former could produce significant levels of ethylene during the ripening of fruits. Ethylene was produced during the early stages of fruit developments, which may indicate that the mechanism of ethylene perception occurs in these fruits prior to ripening.

Characterization of strawberry (Fragaria vesca) sequence genome

Background In order to understand strawberry genes’ structure and evolution in this era of genomics, it is important to know the general statistical characteristics of the gene, intron and exon structures of strawberry and the expression of genes on different parts of strawberry genome. In the present study, about 32,422 genes on strawberry chromosomes were evaluated, and a number of bioinformatic softwares were used to analyze the characteristics of genes, exons and introns, expression of genes in different regions on the chromosomes. Also, the positions of strawberry centromeres were predicted. Results Our results showed that, there are differences in the various features of different chromosomes and also vary in different parts of the same chromosome. The longer the number of genes, the longer the length of chromosome. The average length of genes is about 2809bp and the length of the individual gene is 0–2000bp with 5.3 exons and 4.3 introns per gene. The average length of the exon was 229bp and the intron was 413bp. Among the evaluated genes, ehe intronless gene accounted for 20.05%. Consistently a same trend with the expression levels of the same parts of the gene on a chromosome in different organizations was observed. Finally, the number of genes was positively correlated with the number of intronless, and there was a negative correlation of the length of the gene. The length of the gene depends primarily on the length of the intron, and the length of the exon has little effect on it. The number of exons was negatively correlated with the length of the exons, and the intron was also true. Conclusion The results of this investigation could definitely provide a significant foundation for further research on function analysis of gene family in Strawberry.Background: In order to understand strawberry genes structure and evolution in this era of genomics, it is important to know the general statistical characteristics of the gene, intron and exon structures of strawberry and the expression of genes on different parts of strawberry genome. In the present study, about 32,422 genes on strawberry chromosomes were evaluated, and a number of bioinformatic softwares were used to analyze the characteristics of genes, exons and introns, expression of genes in different regions on the chromosomes. Also, the positions of strawberry centromeres were predicted. Results: Our results showed that, there are differences in the various features of different chromosomes and also vary in different parts of the same chromosome. The longer the number of genes, the longer the length of chromosome. The average length of genes is about 2809bp and the length of the individual gene is 0-2000bp with 5.3 exons and 4.3 introns per gene. The average length of the exon was 229bp and the intron was 413bp. Among the evaluated genes, ehe intronless gene accounted for 20.05%. Consistently a same trend with the expression levels of the same parts of the gene on a chromosome in different organizations was observed. Finally, the number of genes was positively correlated with the number of intronless, and there was a negative correlation of the length of the gene. The length of the gene depends primarily on the length of the intron, and the length of the exon has little effect on it. The number of exons was negatively correlated with the length of the exons, and the intron was also true. Conclusion: The results of this investigation could definitely provide a significant foundation for further research on function analysis of gene family in Strawberry.

The Regulatory and Signaling Roles of Glutathione in Modulating Abiotic Stress Responses and Tolerance

Glutathione (GSH) plays a key role in the maintenance of tissue antioxidant defence and in the regulation of redox-sensitive signal transduction. The size of the GSH pool and its redox status are strongly correlated with the tolerance of plants. The effect of GSH on plant stress resistance is achieved mainly through the cycle of ascorbate (AsA)-GSH producing dehydroascorbate (DHA) re-reduction, in which GSH is intermediate in the recycling of H2O2 reduction and the recycling of GSH is regulated by the glutathione reductase (GR) enzyme. Under oxidative stress, H2O2 and reactive oxygen species (ROS) can be reduced by GSH, while GSH is oxidized to oxidized glutathione (GSSG). Under normal physiological conditions, GSSG can be reduced to GSH by GR in the presence and with the involvement of NADPH, thus creating the redox cycle. AsA/DHA, GSH/GSSG, NADPH/NADP are the three most important interconnected and coordinated redox pairs in plant cells, and plants can scavenge ROS and strengthen their resistance to abiotic stresses by modulating the status of redox pairs; thus the redox metabolism pathways are initiated by diverse environmental stresses. In addition, GSH can regulate the ROS signal transduction pathway, and ROS levels depend on the redox status of redox pairs in plant cells. GSH can activate the genes involved in phytoalexin biosynthesis to repress the accumulation of plant toxin. H2O2 can strengthen this effect through the up-regulation of GSSG. When H2O2 reaches a higher level, the biosynthesis of GSH is stimulated, while GSH, on the other hand, can mediate the response of the plant to the H2O2 signal.