Genome-wide identification of the MIOX gene family and their expression profile in cotton development and response to abiotic stress

The enzyme myo-inositol oxygenase (MIOX) catalyzes the myo-inositol into glucuronic acid. In this study, 6 MIOX genes were identified from all of the three diploid cotton species (Gossypium arboretum, Gossypium herbaceum and Gossypium raimondii) and Gossypioides kirkii, 12 MIOX genes were identified from two domesticated tetraploid cottons Gossypium hirsutum, Gossypium barbadense, and 11 MIOX genes were identified from three wild tetraploid cottons Gossypium tomentosum, Gossypium mustelinum and Gossypium darwinii. The number of MIOX genes in tetraploid cotton genome is roughly twice that of diploid cotton genome. Members of MIOX family were classified into six groups based on the phylogenetic analysis. Integrated analysis of collinearity events and chromosome locations suggested that both whole genome duplication and segmental duplication events contributed to the expansion of MIOX genes during cotton evolution. The ratios of non-synonymous (Ka) and synonymous (Ks) substitution rates revealed that purifying selection was the main force driving the evolution of MIOX genes. Numerous cis-acting elements related to light responsive element, defense and stress responsive element were identified in the promoter of the MIOX genes. Expression analyses of MIOX genes based on RNA-seq data and quantitative real time PCR showed that MIOX genes within the same group shared similar expression patterns with each other. All of these results provide the foundation for further study of the biological functions of MIOX genes in cotton environmental adaptability.

Genome-Wide Identification and Characterization of The MIOX Gene Family in Cotton

Background: The enzyme myo-inositol oxygenase (MIOX) catalyzes the myo-inositol into glucuronic acid. Previous studies indicated that MIOX may play an important role in plant responses to abiotic stresses. Cotton is a major source of natural and renewable textile. However, the MIOX gene family of cotton has not been systematically identified and characterized yet.Results: In this study, 6 MIOX genes were identified from all of the three diploid cotton species (Gossypium arboretum, Gossypium herbaceum and Gossypium raimondii), 12 MIOX genes were identified from two domesticated tetraploid cottons Gossypium hirsutum, Gossypium barbadense, and 11 MIOX genes were identified from three wild tetraploid cottons Gossypium tomentosum, Gossypium mustelinum and Gossypium darwinii. The number of MIOX genes in tetraploid cotton genome is roughly twice that of diploid cotton genome. Members of MIOX family were classified into six groups based on the phylogenetic analysis. Integrated analysis of collinearity events and chromosome locations suggested that both whole genome duplication and segmental duplication events contributed to the expansion of MIOX genes during cotton evolution. The ratios of non-synonymous (Ka) and synonymous (Ks) substitution rates revealed that purifying selection was the main force driving the evolution of MIOX genes. Numerous cis-acting elements related to light responsive element, defense and stress responsive element were identified in the promoter of the MIOX genes. Expression analyses of MIOX genes based on RNA-seq data showed that MIOX genes within the same group shared similar expression patterns with each other.Conclusions: In this work, we systematically analyzed MIOX genes from eight Gossypium genomes and the Gossypioides kirkii genome using a set of bioinformatics approaches. All of these results provide the foundation for further study of the biological functions of MIOX genes in cotton environmental adaptability.

Analysis of pollen fertility in aneuploid hybrids with substitutions for specific chromosomes or their arms in cotton G.hirsutum L.

Analysis of pollen fertility in interspecific aneuploid F1 hybrids with substitutions of specific chromosomes (2, 4, 6, 7, 18) and chromosome arms (telo 6, telo11) of the cotton genome G. hirsutum L. revealed a decrease in fertility in all hybrid plants. It was shown that hybrid monosomics for chromosome 2 were characterized by a slight decrease in pollen fertility; hybrid monosomics of different families with substitution on chromosome 4 and on chromosome 6 - a significant decrease; hybrid monosomics with substitution on chromosome 7 and 18, as well as monotelodisome hybrid plants with substitution of an individual arm of chromosome 6 or 11 - a strong decrease, which indicated the existence of specific differences in pollen fertility in hybrid monosomic plants with substitution of specific chromosomes of the cotton genome due to the formation of partially unbalanced haplo-deficient gametes.