using-phylogenetic-analysis-to-investigate-eukaryotic-gene-origin

Using Phylogenetic Analysis to Investigate Eukaryotic Gene Origin

Phylogenetic analysis uses nucleotide or amino acid sequences or other parameters, such as domain sequences and three-dimensional structure, to construct ...

China Three Gorges University

This study investigated the role of the sugar transporter OsSWEET11 during the early stage of rice caryopsis development using β-glucoronidase (GUS) to represent its expression, together with clustered regularly interspaced short palindromic repeats-CRISPR-associated protein 9 (CRISPR-Cas9)-mediated knockout, cross-fertilization and RNA sequencing (RNA-seq) analyses. The results showed that OsSWEET11 was expressed strongly in developing caryopsis, particularly in the ovular vascular trace, nucellar epidermis and cross cells. The knockout of OsSWEET11 significantly decreased the sucrose concentration in the mutant embryo sacs and led to defective grain filling compared with that of the wild-type (WT) plant. Moreover, the expression of 2,549 genes in the mutant caryopsis was affected. The grain weight and seed setting percentage were also decreased in the mutants. The cross-fertilization of the mutant and WT rice revealed that the mutated maternal donor induced defective grain filling. These results strongly suggested that OsSWEET11 played an important role in sucrose release from maternal tissue to the maternal-filial interface during the early stage of caryopsis development. It might also induce sucrose release from the ovular vascular trace and cross cells of developing caryopsis. These findings bridge the gap in the understanding of post-phloem sugar transport during the early stage of rice caryopsis development.

Essential Role of Sugar Transporter OsSWEET11 During the Early Stage of Rice Grain Filling.

The dioecious relic Cercidiphyllum japonicum is one of two species of the sole genus Cercidiphyllum, with a tight inflorescence lacking an apparent perianth structure. In addition, its systematic place has been much debated and, so far researches have mainly focused on its morphology and chloroplast genes. In our investigation, we identified 10 floral organ identity genes, including four A-class, three B-class, two C-class and one D-class. Phylogenetic analyses showed that all ten genes are grouped with Saxifragales plants, which confirmed the phylogenetic place of C. japonicum. Expression patterns of those genes were examined by quantitative reverse transcriptase PCR, with some variations that did not completely coincide with the ABCDE model, suggesting some subfunctionalization. As well, our research supported the idea that thebract actually is perianth according to our morphological and molecular analyses in Cercidiphyllum japonicum.

Floral organ MADS-box genes in Cercidiphyllum japonicum (Cercidiphyllaceae): Implications for systematic evolution and bracts definition.

Double-flower phenotype is more popular and attractive in garden and ornamental plants. There is great interest in exploring the molecular mechanisms underlying the double-flower formation for further breeding and selection. , a commercial ornamental shrub of the Rosaceae family, is considered an excellent system to determine the mechanisms of morphological alterations, because it naturally has a single-flower form and double-flower variant with homeotic conversion of stamens into petals and carpels into leaf-like carpels. In this study,  ( homolog of single-flower ) and  ( homolog of double-flower ) were isolated and characterized as two  () homologs that occur strictly in single- and double-flower , respectively. Our sequence comparison showed that  is derived from ectopic splicing with the insertion of a 2411 bp transposon-like fragment, which might disrupt mRNA accumulation and protein function, into intron 1. Ectopic expression analysis in  revealed that  is highly conserved in specifying carpel and stamen identities. However,  did not show any putative C-class function in floral development. Moreover, yeast-two-hybrid assays showed that Sf-KjAG can interact with KjAGL2, KjAGL9, and KjAP1, whereas Df-KjAG has lost interactions with these floral identity genes. In addition, loss-of-function of  affected not only its own expression, but also that of other putative floral organ identity genes such as , and . In conclusion, our findings suggest that double-flower formation in  can be attributed to , which appears to be a mutant produced by the insertion of a transposon-like fragment in the normal  homolog () of single-flower .  and  are different variations only distinguished by a transposon-like fragment insertion which lead to the evolutionary transformation from single-flower to double-flowers morphogenesis in .

Article	Year
Essential Role of Sugar Transporter OsSWEET11 During the Early Stage of Rice Grain Filling. Plant & cell physiology\| PubMed ID: 28371825	2017
Floral organ MADS-box genes in Cercidiphyllum japonicum (Cercidiphyllaceae): Implications for systematic evolution and bracts definition. PloS one\| PubMed ID: 28562649	2017
Isolation and Characterization of Genes Associated With Double-Flower Morphogenesis in (Rosaceae). Frontiers in plant science\| PubMed ID: 30050547	2018

Dechun Zhang

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