Fruit development of the diploid kiwifruit, Actinidia chinensis 'Hort16A'

<p>Abstract</p> <p>Background</p> <p>With the advent of high throughput genomic tools, it is now possible to undertake detailed molecular studies of individual species outside traditional model organisms. Combined with a good understanding of physiological processes, these tools allow researchers to explore natural diversity, giving a better understanding of biological mechanisms. Here a detailed study of fruit development from anthesis through to fruit senescence is presented for a non-model organism, kiwifruit, <it>Actinidia chinensis </it>('Hort16A').</p> <p>Results</p> <p>Consistent with previous studies, it was found that many aspects of fruit morphology, growth and development are similar to those of the model fruit tomato, except for a striking difference in fruit ripening progression. The early stages of fruit ripening occur as the fruit is still growing, and many ripening events are not associated with autocatalytic ethylene production (historically associated with respiratory climacteric). Autocatalytic ethylene is produced late in the ripening process as the fruit begins to senesce.</p> <p>Conclusion</p> <p>By aligning <it>A. chinensis </it>fruit development to a phenological scale, this study provides a reference framework for subsequent physiological and genomic studies, and will allow cross comparison across fruit species, leading to a greater understanding of the diversity of fruits found across the plant kingdom.</p

A MADS-box gene-induced early flowering pear (Pyrus communis L.) for accelerated pear breeding

There have been a considerable number of studies that have successfully sped up the flowering cycle in woody perennial horticultural species. One particularly successful study in apple (Malus domestica) accelerated flowering using a silver birch (Betula pendula) APETALA1/FRUITFULL MADS-box gene BpMADS4, which yielded a good balance of vegetative growth to support subsequent flower and fruit development. In this study, BpMADS4 was constitutively expressed in European pear (Pyrus communis) to establish whether this could be used as a tool in a rapid pear breeding program. Transformed pear lines flowered within 6–18 months after grafting onto a quince (Cydonia oblonga) rootstock. Unlike the spindly habit of early flowering apples, the early flowering pear lines displayed a normal tree-like habit. Like apple, the flower appearance was normal, and the flowers were fertile, producing fruit and seed upon pollination. Seed from these transformed lines were germinated and 50% of the progeny flowered within 3 months of sowing, demonstrating a use for these in a fast breeding program

A manually annotated Actinidia chinensis var. chinensis (kiwifruit) genome highlights the challenges associated with draft genomes and gene prediction in plants

Most published genome sequences are drafts, and most are dominated by computational gene prediction. Draft genomes typically incorporate considerable sequence data that are not assigned to chromosomes, and predicted genes without quality confidence measures. The current Actinidia chinensis (kiwifruit) 'Hongyang' draft genome has 164\ua0Mb of sequences unassigned to pseudo-chromosomes, and omissions have been identified in the gene models

Image_1_A MADS-box gene-induced early flowering pear (Pyrus communis L.) for accelerated pear breeding.tif

There have been a considerable number of studies that have successfully sped up the flowering cycle in woody perennial horticultural species. One particularly successful study in apple (Malus domestica) accelerated flowering using a silver birch (Betula pendula) APETALA1/FRUITFULL MADS-box gene BpMADS4, which yielded a good balance of vegetative growth to support subsequent flower and fruit development. In this study, BpMADS4 was constitutively expressed in European pear (Pyrus communis) to establish whether this could be used as a tool in a rapid pear breeding program. Transformed pear lines flowered within 6–18 months after grafting onto a quince (Cydonia oblonga) rootstock. Unlike the spindly habit of early flowering apples, the early flowering pear lines displayed a normal tree-like habit. Like apple, the flower appearance was normal, and the flowers were fertile, producing fruit and seed upon pollination. Seed from these transformed lines were germinated and 50% of the progeny flowered within 3 months of sowing, demonstrating a use for these in a fast breeding program.</p

Military pollution in no war zone: the military representation in the local media

This article analyses the local press’ representation of an experimental military activity located in Sardinia (Italy). We seek to assess the changes of the portrait of the military over a 57-year period, looking at the relevant narratives that have occurred in the local press. The authors’ perspective scrutinises the local print media as a key medium for understanding representations of the military and its activities. The adoption of frame analysis and the study of the frame effects highlight two main historical storylines. In the early stages of the military base, the military was portrayed as an agent of change, a frame defined as modernity versus tradition. A gradual decline followed in the wake of growing concerns related to the after-effects of experimental military activities, and the military came to be perceived as a threat to local community, military personnel and the environment

A genomics approach to understanding the role of auxin in apple (<it>Malus </it>x <it>domestica) </it>fruit size control

<p>Abstract</p> <p>Background</p> <p>Auxin is an important phytohormone for fleshy fruit development, having been shown to be involved in the initial signal for fertilisation, fruit size through the control of cell division and cell expansion, and ripening related events. There is considerable knowledge of auxin-related genes, mostly from work in model species. With the apple genome now available, it is possible to carry out genomics studies on auxin-related genes to identify genes that may play roles in specific stages of apple fruit development.</p> <p>Results</p> <p>High amounts of auxin in the seed compared with the fruit cortex were observed in 'Royal Gala' apples, with amounts increasing through fruit development. Injection of exogenous auxin into developing apples at the start of cell expansion caused an increase in cell size. An expression analysis screen of auxin-related genes involved in auxin reception, homeostasis, and transcriptional regulation showed complex patterns of expression in each class of gene. Two mapping populations were phenotyped for fruit size over multiple seasons, and multiple quantitative trait loci (QTLs) were observed. One QTL mapped to a region containing an Auxin Response Factor (<it>ARF106</it>). This gene is expressed during cell division and cell expansion stages, consistent with a potential role in the control of fruit size.</p> <p>Conclusions</p> <p>The application of exogenous auxin to apples increased cell expansion, suggesting that endogenous auxin concentrations are at least one of the limiting factors controlling fruit size. The expression analysis of <it>ARF106 </it>linked to a strong QTL for fruit weight suggests that the auxin signal regulating fruit size could partially be modulated through the function of this gene. One class of gene (<it>GH3</it>) removes free auxin by conjugation to amino acids. The lower expression of these <it>GH3 </it>genes during rapid fruit expansion is consistent with the apple maximising auxin concentrations at this point.</p

Additional file 4: of A manually annotated Actinidia chinensis var. chinensis (kiwifruit) genome highlights the challenges associated with draft genomes and gene prediction in plants

BLASTP comparison of manually edited gene models to the revised ‘Hongyang’ gene models. List of best reciprocal BLASTp matches between the revised Actinidia chinensis ‘Hongyang’ genes [18]and the Red5 gene set (XLSX 436 kb