Transcriptome analysis and identification of genes associated with floral transition and fruit development in rabbiteye blueberry (Vaccinium ashei)

Flowering and fruit set are important traits affecting fruit quality and yield in rabbiteye blueberry (Vaccinium ashei). Intense efforts have been made to elucidate the influence of vernalization and phytohormones on flowering, but the molecular mechanisms of flowering and fruit set remain unclear. To unravel these mechanisms, we performed transcriptome analysis to explore blueberry transcripts from flowering to early fruit stage. We divided flowering and fruit set into flower bud (S2), initial flower (S3), bloom flower (S4), pad fruit (S5), and cup fruit (S6) based on phenotype and identified 1,344, 69, 658, and 189 unique differentially expressed genes (DEGs) in comparisons of S3/S2, S4/S3, S5/S4, and S6/S5, respectively. There were obviously more DEGs in S3/S2 and S5/S4 than in S4/S3, and S6/S5, suggesting that S3/S2 and S5/S4 represent major transitions from buds to fruit in blueberry. GO and KEGG enrichment analysis indicated these DEGs were mostly enriched in phytohormone biosynthesis and signaling, transporter proteins, photosynthesis, anthocyanins biosynthesis, disease resistance protein and transcription factor categories, in addition, transcript levels of phytohormones and transporters changed greatly throughout the flowering and fruit set process. Gibberellic acid and jasmonic acid mainly acted on the early stage of flowering development like expression of the florigen gene FT, while the expression of auxin response factor genes increased almost throughout the process from bud to fruit development. Transporter proteins were mainly associated with minerals during the early flowering development stage and sugars during the early fruit stage. At the early fruit stage, anthocyanins started to accumulate, and the fruit was susceptible to diseases such as fungal infection. Expression of the transcription factor MYB86 was up-regulated during initial fruit development, which may promote anthocyanin accumulation. These results will aid future studies exploring the molecular mechanism underlying flowering and fruit set of rabbiteye blueberry.

Potential function of CbuSPL and gene encoding its interacting protein during flowering in Catalpa bungei

Abstract“Bairihua”, a variety of the Catalpa bungei, has a large amount of flowers and a long flowering period which make it an excellent material for flowering researches in trees. SPL is one of the hub genes that regulate both flowering transition and development. Here, a SPL homologues CbuSPL9 was cloned using degenerate primers with RACE. Expression studies during flowering transition in Bairihua and ectopic expression in Arabidopsis showed that CbuSPL9 was functional similarly with its Arabidopsis homologues. In the next step, we used Y2H to identify the proteins that could interact with CbuSPL9. HMGA, an architectural transcriptional factor, was identified and cloned for further research. BiFC and BLI showed that CbuSPL9 could form a heterodimer with CbuHMGA in the nucleus. The expression analysis showed that CbuHMGA had a similar expression trend to that of CbuSPL9 during flowering in “Bairihua”. Intriguingly, ectopic expression of CbuHMGA in Arabidopsis would lead to aberrant flowers, but did not effect flowering time. Taken together, our results implied a novel pathway that ChuSPL9 regulated flowering development, but not flowering transition, with the participation of ChuHMGA. Further investments need to be done to verify the details of this pathway.

Flowering Development of Longan (Dimocarpus longan Lour) ‘Diamond river’

‘Diamond river’ is introduction plant that cultivated in Indonesian. Development of longan flower divided into eight stadium during 28 days. First and second stadium is the induction phase that lasts for 8 days, this phase is characterized by a change in color of the leaves become older by using the Munsell color charts for plant tissues indicate the scale of 7.5 GY (4/4) to GY 7.5 scale (3\2). Third stadium is the phase of flower initiation occurred by day eigth. Initiation stage appearance were showed by merristem axilar, which will form part of primordial flower. Fourth to seventh stadium are phase that a differentiation occurred on day 12 to day 24. Differentiation phase showed the development in suitable with the typical angiosperms are sepals, stamens, petals and pistils. Eighth stadium is the phase of anthesis occurred on day 28. In the phase of anthesis, flowers have undergone a process of pollination and fertilization. Keywords: Development, Diamond river, Flowering, stadium

Simulating fababean development, growth, and yield in Australia

The capability to simulate fababean (Vicia faba L.) production across the range of environments in which it is grown in Australia provides a tool for assessing agronomic and management options for the crop. This paper describes the building and testing of a model of fababean (cv. Fiord) development and growth, designed for use in the cropping systems simulator, APSIM. Parameters describing leaf area expansion, radiation interception, biomass accumulation and partitioning, root growth, water use, and nitrogen accumulation were sourced from the literature or developed from experiments conducted by the authors. In addition, parameters defining phenological development in response to temperature and photoperiod were derived from a comprehensive dataset of times to flowering and maturity.Routines for pre-flowering phenology predicted time to flowering ranging from 43 to 94 days with a root mean squared deviation (RMSD) of 4.3 days. Post-flowering development could not be satisfactorily predicted using thermal time alone; analysis of the collated data suggested that the lengths of some post-flowering phases were related to photoperiod. With incorporation of a photoperiod effect on post-flowering development, time from sowing to maturity was simulated with an R2 of 92% and an RMSD of 6.7 days.The model was tested over a diverse range of latitudinal and climatic conditions within Australia, using data from experiments in which sowing date, crop density, and water supply varied. Observed grain yield (n = 42) varied from 500 to 5600 kg/ha. In general, observed biomass and yield patterns within a growing season were reproduced well. Simulated grain yield explained 87% of the variance in observed yields (RMSD = 466 kg/ha). Apart from demonstrating the capability of the model over a wide range of growing conditions, the tests highlighted a number of areas for future improvement, including accounting for lodging, variation in harvest index under wet conditions, and accurate simulation of the response of leaf area expansion to mild levels of water deficit.